-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy path11802.html
245 lines (236 loc) · 110 KB
/
11802.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
<!DOCTYPE html><html lang="zh-CN" data-theme="light"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width,initial-scale=1"><title>Bean的加载和控制 | 征蓬</title><meta name="keywords" content="SpringBoot"><meta name="author" content="huy"><meta name="copyright" content="huy"><meta name="format-detection" content="telephone=no"><meta name="theme-color" content="#ffffff"><meta name="description" content="Bean的加载方式、加载控制（编程式、注解式）、依赖属性配置">
<meta property="og:type" content="article">
<meta property="og:title" content="Bean的加载和控制">
<meta property="og:url" content="http://example.com/11802.html">
<meta property="og:site_name" content="征蓬">
<meta property="og:description" content="Bean的加载方式、加载控制（编程式、注解式）、依赖属性配置">
<meta property="og:locale" content="zh_CN">
<meta property="og:image" content="http://example.com/pics/scenery/03.jpg">
<meta property="article:published_time" content="2022-05-02T09:59:38.000Z">
<meta property="article:modified_time" content="2022-05-17T01:05:49.343Z">
<meta property="article:author" content="huy">
<meta property="article:tag" content="SpringBoot">
<meta name="twitter:card" content="summary">
<meta name="twitter:image" content="http://example.com/pics/scenery/03.jpg"><link rel="shortcut icon" href="/pics/avatar/8.png"><link rel="canonical" href="http://example.com/11802"><link rel="preconnect" href="//cdn.jsdelivr.net"/><link rel="stylesheet" href="/css/index.css"><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@fortawesome/fontawesome-free/css/all.min.css" media="print" onload="this.media='all'"><link rel="stylesheet" href="https://lf3-cdn-tos.bytecdntp.com/cdn/expire-1-M/node-snackbar/0.1.16/snackbar.min.css" media="print" onload="this.media='all'"><link rel="stylesheet" href="/font/wcsf.ttf" media="print" onload="this.media='all'"><script>const GLOBAL_CONFIG = {
root: '/',
algolia: undefined,
localSearch: {"path":"search.xml","languages":{"hits_empty":"找不到您查询的内容：${query}"}},
translate: undefined,
noticeOutdate: undefined,
highlight: {"plugin":"highlighjs","highlightCopy":true,"highlightLang":true,"highlightHeightLimit":false},
copy: {
success: '复制成功',
error: '复制错误',
noSupport: '浏览器不支持'
},
relativeDate: {
homepage: false,
post: false
},
runtime: '',
date_suffix: {
just: '刚刚',
min: '分钟前',
hour: '小时前',
day: '天前',
month: '个月前'
},
copyright: undefined,
lightbox: 'fancybox',
Snackbar: {"chs_to_cht":"你已切换为繁体","cht_to_chs":"你已切换为简体","day_to_night":"你已切换为深色模式","night_to_day":"你已切换为浅色模式","bgLight":"#49b1f5","bgDark":"#121212","position":"bottom-left"},
source: {
jQuery: 'https://lf26-cdn-tos.bytecdntp.com/cdn/expire-1-M/jquery/3.6.0/jquery.min.js',
justifiedGallery: {
js: 'https://cdn.jsdelivr.net/npm/justifiedGallery/dist/js/jquery.justifiedGallery.min.js',
css: 'https://cdn.jsdelivr.net/npm/justifiedGallery/dist/css/justifiedGallery.min.css'
},
fancybox: {
js: 'https://cdn.jsdelivr.net/npm/@fancyapps/fancybox@latest/dist/jquery.fancybox.min.js',
css: 'https://cdn.jsdelivr.net/npm/@fancyapps/fancybox@latest/dist/jquery.fancybox.min.css'
}
},
isPhotoFigcaption: false,
islazyload: false,
isanchor: false
}</script><script id="config-diff">var GLOBAL_CONFIG_SITE = {
title: 'Bean的加载和控制',
isPost: true,
isHome: false,
isHighlightShrink: false,
isToc: true,
postUpdate: '2022-05-17 09:05:49'
}</script><noscript><style type="text/css">
#nav {
opacity: 1
}
.justified-gallery img {
opacity: 1
}
#recent-posts time,
#post-meta time {
display: inline !important
}
</style></noscript><script>(win=>{
win.saveToLocal = {
set: function setWithExpiry(key, value, ttl) {
if (ttl === 0) return
const now = new Date()
const expiryDay = ttl * 86400000
const item = {
value: value,
expiry: now.getTime() + expiryDay,
}
localStorage.setItem(key, JSON.stringify(item))
},
get: function getWithExpiry(key) {
const itemStr = localStorage.getItem(key)
if (!itemStr) {
return undefined
}
const item = JSON.parse(itemStr)
const now = new Date()
if (now.getTime() > item.expiry) {
localStorage.removeItem(key)
return undefined
}
return item.value
}
}
win.getScript = url => new Promise((resolve, reject) => {
const script = document.createElement('script')
script.src = url
script.async = true
script.onerror = reject
script.onload = script.onreadystatechange = function() {
const loadState = this.readyState
if (loadState && loadState !== 'loaded' && loadState !== 'complete') return
script.onload = script.onreadystatechange = null
resolve()
}
document.head.appendChild(script)
})
win.activateDarkMode = function () {
document.documentElement.setAttribute('data-theme', 'dark')
if (document.querySelector('meta[name="theme-color"]') !== null) {
document.querySelector('meta[name="theme-color"]').setAttribute('content', '#0d0d0d')
}
}
win.activateLightMode = function () {
document.documentElement.setAttribute('data-theme', 'light')
if (document.querySelector('meta[name="theme-color"]') !== null) {
document.querySelector('meta[name="theme-color"]').setAttribute('content', '#ffffff')
}
}
const t = saveToLocal.get('theme')
if (t === 'dark') activateDarkMode()
else if (t === 'light') activateLightMode()
const asideStatus = saveToLocal.get('aside-status')
if (asideStatus !== undefined) {
if (asideStatus === 'hide') {
document.documentElement.classList.add('hide-aside')
} else {
document.documentElement.classList.remove('hide-aside')
}
}
const detectApple = () => {
if (GLOBAL_CONFIG_SITE.isHome && /iPad|iPhone|iPod|Macintosh/.test(navigator.userAgent)){
document.documentElement.classList.add('apple')
}
}
detectApple()
})(window)</script><link rel="stylesheet" href="/css/custom.css" media="defer" onload="this.media='all'"><!-- hexo injector head_end start --><link rel="stylesheet" href="https://npm.elemecdn.com/hexo-butterfly-tag-plugins-plus@latest/lib/assets/font-awesome-animation.min.css" media="defer" onload="this.media='all'"><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/hexo-butterfly-tag-plugins-plus@latest/lib/tag_plugins.min.css" media="defer" onload="this.media='all'"><script async src="https://npm.elemecdn.com/hexo-butterfly-tag-plugins-plus@latest/lib/assets/carousel-touch.js"></script><!-- hexo injector head_end end --><meta name="generator" content="Hexo 5.4.1"></head><body><div id="sidebar"><div id="menu-mask"></div><div id="sidebar-menus"><div class="avatar-img is-center"><img src="/pics/Asoul/8.jpg" onerror="onerror=null;src='/img/friend_404.gif'" alt="avatar"/></div><div class="site-data"><div class="data-item is-center"><div class="data-item-link"><a href="/archives/"><div class="headline">文章</div><div class="length-num">54</div></a></div></div><div class="data-item is-center"><div class="data-item-link"><a href="/tags/"><div class="headline">标签</div><div class="length-num">17</div></a></div></div><div class="data-item is-center"><div class="data-item-link"><a href="/categories/"><div class="headline">分类</div><div class="length-num">12</div></a></div></div></div><hr/><div class="menus_items"><div class="menus_item"><a class="site-page" href="/"><i class="fa-fw fas fa-home"></i><span> 首页</span></a></div><div class="menus_item"><a class="site-page" href="/archives/"><i class="fa-fw fas fa-archive"></i><span> 时间轴</span></a></div><div class="menus_item"><a class="site-page" href="/tags/"><i class="fa-fw fas fa-tags"></i><span> 标签</span></a></div><div class="menus_item"><a class="site-page" href="/categories/"><i class="fa-fw fas fa-folder-open"></i><span> 分类</span></a></div><div class="menus_item"><a class="site-page" href="/about/"><i class="fa-fw fas fa-heart"></i><span> 关于</span></a></div></div></div></div><div class="post" id="body-wrap"><header class="post-bg" id="page-header" style="background-image: url('/pics/scenery/03.jpg')"><nav id="nav"><span id="blog_name"><a id="site-name" href="/">征蓬</a></span><div id="menus"><div id="search-button"><a class="site-page social-icon search"><i class="fas fa-search fa-fw"></i><span> 搜索</span></a></div><div class="menus_items"><div class="menus_item"><a class="site-page" href="/"><i class="fa-fw fas fa-home"></i><span> 首页</span></a></div><div class="menus_item"><a class="site-page" href="/archives/"><i class="fa-fw fas fa-archive"></i><span> 时间轴</span></a></div><div class="menus_item"><a class="site-page" href="/tags/"><i class="fa-fw fas fa-tags"></i><span> 标签</span></a></div><div class="menus_item"><a class="site-page" href="/categories/"><i class="fa-fw fas fa-folder-open"></i><span> 分类</span></a></div><div class="menus_item"><a class="site-page" href="/about/"><i class="fa-fw fas fa-heart"></i><span> 关于</span></a></div></div><div id="toggle-menu"><a class="site-page"><i class="fas fa-bars fa-fw"></i></a></div></div></nav><div id="post-info"><h1 class="post-title">Bean的加载和控制</h1><div id="post-meta"><div class="meta-firstline"><span class="post-meta-date"><i class="far fa-calendar-alt fa-fw post-meta-icon"></i><span class="post-meta-label">发表于</span><time class="post-meta-date-created" datetime="2022-05-02T09:59:38.000Z" title="发表于 2022-05-02 17:59:38">2022-05-02</time><span class="post-meta-separator">|</span><i class="fas fa-history fa-fw post-meta-icon"></i><span class="post-meta-label">更新于</span><time class="post-meta-date-updated" datetime="2022-05-17T01:05:49.343Z" title="更新于 2022-05-17 09:05:49">2022-05-17</time></span><span class="post-meta-categories"><span class="post-meta-separator">|</span><i class="fas fa-inbox fa-fw post-meta-icon"></i><a class="post-meta-categories" href="/categories/SpringBoot/">SpringBoot</a></span></div><div class="meta-secondline"></div></div></div></header><main class="layout" id="content-inner"><div id="post"><article class="post-content" id="article-container"><h2 id="Bean的加载方式">Bean的加载方式</h2>
<h3 id="第一种：XML">第一种：XML</h3>
<p><strong>使用该方式声明 Bean 时，Spring 会调用 Bean 中的无参构造方法。</strong></p>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">修改配置文件</button></li><li class="tab"><button type="button" data-href="#test4-2">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-3">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight xml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta"><?xml version="1.0" encoding="UTF-8"?></span></span><br><span class="line"><span class="tag"><<span class="name">beans</span> <span class="attr">xmlns</span>=<span class="string">"http://www.springframework.org/schema/beans"</span></span></span><br><span class="line"><span class="tag"> <span class="attr">xmlns:xsi</span>=<span class="string">"http://www.w3.org/2001/XMLSchema-instance"</span></span></span><br><span class="line"><span class="tag"> <span class="attr">xsi:schemaLocation</span>=<span class="string">"http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"</span>></span></span><br><span class="line"> <span class="comment"><!-- XML方式声明自定义 Bean --></span></span><br><span class="line"> <span class="tag"><<span class="name">bean</span> <span class="attr">id</span>=<span class="string">"cat"</span> <span class="attr">class</span>=<span class="string">"com.bean.Cat"</span> <span class="attr">scope</span> = <span class="string">"singleton"</span>></span><span class="tag"></<span class="name">bean</span>></span></span><br><span class="line"></span><br><span class="line"> <span class="comment"><!-- XML方式声明第三方 Bean --></span></span><br><span class="line"> <span class="tag"><<span class="name">bean</span> <span class="attr">id</span>=<span class="string">"fastJson"</span> <span class="attr">class</span>=<span class="string">"com.alibaba.fastjson.JSONObject"</span>></span><span class="tag"></<span class="name">bean</span>></span></span><br><span class="line"><span class="tag"></<span class="name">beans</span>></span></span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App1</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> ApplicationContext context = <span class="keyword">new</span> ClassPathXmlApplicationContext(<span class="string">"applicationContext1.xml"</span>);</span><br><span class="line"> String[] names = context.getBeanDefinitionNames();</span><br><span class="line"> <span class="keyword">for</span> (String name : names) {</span><br><span class="line"> System.out.println(name);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp1.png" alt=""></p><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
<h3 id="第二种：注解">第二种：注解</h3>
<ol>
<li>使用 <code>@Component</code> 及其衍生注解，<code>@Controller</code>、<code>@Service</code>、<code>@Repository</code> 定义Bean。</li>
<li>使用 <code>@Bean</code> 定义第三方 Bean，并将其所在类定义为配置类或 Bean，<code>@Configuration</code>。</li>
</ol>
<h4 id="自定义-Bean">自定义 Bean</h4>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">修改配置文件</button></li><li class="tab"><button type="button" data-href="#test4-2">在 bean 上添加注解</button></li><li class="tab"><button type="button" data-href="#test4-3">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-4">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight xml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta"><?xml version="1.0" encoding="UTF-8"?></span></span><br><span class="line"><span class="tag"><<span class="name">beans</span> <span class="attr">xmlns</span>=<span class="string">"http://www.springframework.org/schema/beans"</span></span></span><br><span class="line"><span class="tag"> <span class="attr">xmlns:xsi</span>=<span class="string">"http://www.w3.org/2001/XMLSchema-instance"</span></span></span><br><span class="line"><span class="tag"> <span class="attr">xmlns:context</span>=<span class="string">"http://www.springframework.org/schema/context"</span></span></span><br><span class="line"><span class="tag"> <span class="attr">xsi:schemaLocation</span>=<span class="string">"</span></span></span><br><span class="line"><span class="string"><span class="tag"> http://www.springframework.org/schema/beans</span></span></span><br><span class="line"><span class="string"><span class="tag"> http://www.springframework.org/schema/beans/spring-beans.xsd</span></span></span><br><span class="line"><span class="string"><span class="tag"> http://www.springframework.org/schema/context</span></span></span><br><span class="line"><span class="string"><span class="tag"> http://www.springframework.org/schema/context/spring-context.xsd"</span>></span></span><br><span class="line"></span><br><span class="line"> <span class="comment"><!-- 指定加载 Bean 的位置 --></span></span><br><span class="line"> <span class="tag"><<span class="name">context:component-scan</span> <span class="attr">base-package</span>=<span class="string">"com.bean"</span>/></span></span><br><span class="line"></span><br><span class="line"><span class="tag"></<span class="name">beans</span>></span></span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Component("tom")</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">Cat</span> </span>{</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="meta">@Service("dog")</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">Dog</span> </span>{</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App2</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> ApplicationContext context = <span class="keyword">new</span> ClassPathXmlApplicationContext(<span class="string">"applicationContext2.xml"</span>);</span><br><span class="line"> String[] names = context.getBeanDefinitionNames();</span><br><span class="line"> <span class="keyword">for</span> (String name : names){</span><br><span class="line"> System.out.println(name);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-4"><p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp2-1.png" alt=""></p><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
<h4 id="第三方-Bean">第三方 Bean</h4>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">修改配置文件</button></li><li class="tab"><button type="button" data-href="#test4-2">在 bean 上添加注解</button></li><li class="tab"><button type="button" data-href="#test4-3">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-4">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight xml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta"><?xml version="1.0" encoding="UTF-8"?></span></span><br><span class="line"><span class="tag"><<span class="name">beans</span> <span class="attr">xmlns</span>=<span class="string">"http://www.springframework.org/schema/beans"</span></span></span><br><span class="line"><span class="tag"> <span class="attr">xmlns:xsi</span>=<span class="string">"http://www.w3.org/2001/XMLSchema-instance"</span></span></span><br><span class="line"><span class="tag"> <span class="attr">xmlns:context</span>=<span class="string">"http://www.springframework.org/schema/context"</span></span></span><br><span class="line"><span class="tag"> <span class="attr">xsi:schemaLocation</span>=<span class="string">"</span></span></span><br><span class="line"><span class="string"><span class="tag"> http://www.springframework.org/schema/beans</span></span></span><br><span class="line"><span class="string"><span class="tag"> http://www.springframework.org/schema/beans/spring-beans.xsd</span></span></span><br><span class="line"><span class="string"><span class="tag"> http://www.springframework.org/schema/context</span></span></span><br><span class="line"><span class="string"><span class="tag"> http://www.springframework.org/schema/context/spring-context.xsd"</span>></span></span><br><span class="line"></span><br><span class="line"> <span class="comment"><!-- 指定加载 Bean 的位置 --></span></span><br><span class="line"> <span class="tag"><<span class="name">context:component-scan</span> <span class="attr">base-package</span>=<span class="string">"com.bean,com.config"</span>/></span></span><br><span class="line"></span><br><span class="line"><span class="tag"></<span class="name">beans</span>></span></span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Configuration</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">DbConfig</span> </span>{</span><br><span class="line"></span><br><span class="line"> <span class="meta">@Bean</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> JSONObject <span class="title">jsonObject</span><span class="params">()</span></span>{</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">new</span> JSONObject();</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App2</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> ApplicationContext context = <span class="keyword">new</span> ClassPathXmlApplicationContext(<span class="string">"applicationContext2.xml"</span>);</span><br><span class="line"> String[] names = context.getBeanDefinitionNames();</span><br><span class="line"> <span class="keyword">for</span> (String name : names){</span><br><span class="line"> System.out.println(name);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-4"><p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp2-2.png" alt=""></p><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
<h3 id="第三种：配置类和FactoryBean">第三种：配置类和FactoryBean</h3>
<h4 id="配置类">配置类</h4>
<ol>
<li>
<p>约等于第二种方法，把 XML 配置文件的形式变成配置类。</p>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">新建配置类，并指定扫描范围</button></li><li class="tab"><button type="button" data-href="#test4-2">在 bean 上添加注解</button></li><li class="tab"><button type="button" data-href="#test4-3">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-4">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@ComponentScan({"com.bean", "com.config"})</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">SpringConfig3</span> </span>{</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Configuration</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">DbConfig</span> </span>{</span><br><span class="line"> </span><br><span class="line"> <span class="meta">@Bean</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> JSONObject <span class="title">jsonObject</span><span class="params">()</span></span>{</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">new</span> JSONObject();</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App3</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> ApplicationContext context = <span class="keyword">new</span> AnnotationConfigApplicationContext(SpringConfig3.class);</span><br><span class="line"> String[] names = context.getBeanDefinitionNames();</span><br><span class="line"> <span class="keyword">for</span> (String name : names){</span><br><span class="line"> System.out.println(name);</span><br><span class="line"> }</span><br><span class="line"> </span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-4"><p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp3.png" alt=""></p><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
</li>
<li>
<p>使用 <code>@ImportResource</code> 注解加载配置类并且加载其他的配置文件</p>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">新建配置类，并加载指定的配置文件</button></li><li class="tab"><button type="button" data-href="#test4-2">配置文件</button></li><li class="tab"><button type="button" data-href="#test4-3">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-4">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@ImportResource("applicationContext1.xml")</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">SpringConfig3_2</span> </span>{</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight xml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta"><?xml version="1.0" encoding="UTF-8"?></span></span><br><span class="line"><span class="tag"><<span class="name">beans</span> <span class="attr">xmlns</span>=<span class="string">"http://www.springframework.org/schema/beans"</span></span></span><br><span class="line"><span class="tag"> <span class="attr">xmlns:xsi</span>=<span class="string">"http://www.w3.org/2001/XMLSchema-instance"</span></span></span><br><span class="line"><span class="tag"> <span class="attr">xsi:schemaLocation</span>=<span class="string">"http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"</span>></span></span><br><span class="line"> <span class="comment"><!-- XML方式声明自定义 Bean --></span></span><br><span class="line"> <span class="tag"><<span class="name">bean</span> <span class="attr">id</span>=<span class="string">"cat"</span> <span class="attr">class</span>=<span class="string">"com.bean.Cat"</span>></span><span class="tag"></<span class="name">bean</span>></span></span><br><span class="line"> <span class="tag"><<span class="name">bean</span> <span class="attr">class</span>=<span class="string">"com.bean.Dog"</span>></span><span class="tag"></<span class="name">bean</span>></span></span><br><span class="line"></span><br><span class="line"> <span class="comment"><!-- XML方式声明第三方 Bean --></span></span><br><span class="line"> <span class="tag"><<span class="name">bean</span> <span class="attr">id</span>=<span class="string">"fastJson"</span> <span class="attr">class</span>=<span class="string">"com.alibaba.fastjson.JSONObject"</span>></span><span class="tag"></<span class="name">bean</span>></span></span><br><span class="line"><span class="tag"></<span class="name">beans</span>></span></span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App3_2</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> ApplicationContext context = <span class="keyword">new</span> AnnotationConfigApplicationContext(SpringConfig3_2.class);</span><br><span class="line"> String[] names = context.getBeanDefinitionNames();</span><br><span class="line"> <span class="keyword">for</span> (String name : names){</span><br><span class="line"> System.out.println(name);</span><br><span class="line"> }</span><br><span class="line"> </span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-4"><p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp3-2.png" alt=""></p><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
</li>
</ol>
<h4 id="FactoryBean">FactoryBean</h4>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">实现 FactoryBean 接口</button></li><li class="tab"><button type="button" data-href="#test4-2">配置类</button></li><li class="tab"><button type="button" data-href="#test4-3">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-4">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">DogFactoryBean</span> <span class="keyword">implements</span> <span class="title">FactoryBean</span><<span class="title">Dog</span>> </span>{</span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> Dog <span class="title">getObject</span><span class="params">()</span> <span class="keyword">throws</span> Exception </span>{</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">new</span> Dog();</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="keyword">public</span> Class<?> getObjectType() {</span><br><span class="line"> <span class="keyword">return</span> Dog.class;</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">boolean</span> <span class="title">isSingleton</span><span class="params">()</span> </span>{</span><br><span class="line"> <span class="comment">// 默认为 true</span></span><br><span class="line"> <span class="keyword">return</span> FactoryBean.<span class="keyword">super</span>.isSingleton();</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@ComponentScan({"com.bean", "com.config"})</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">SpringConfig3</span> </span>{</span><br><span class="line"></span><br><span class="line"> <span class="meta">@Bean</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> DogFactoryBean <span class="title">dog</span><span class="params">()</span></span>{</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">new</span> DogFactoryBean();</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App3</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> ApplicationContext context = <span class="keyword">new</span> AnnotationConfigApplicationContext(SpringConfig3.class);</span><br><span class="line"> String[] names = context.getBeanDefinitionNames();</span><br><span class="line"> <span class="keyword">for</span> (String name : names){</span><br><span class="line"> System.out.println(name);</span><br><span class="line"> }</span><br><span class="line"> System.out.println(context.getBean(<span class="string">"dog"</span>));</span><br><span class="line"> <span class="comment">// 测试创建多个对象是否单例</span></span><br><span class="line"> System.out.println(context.getBean(<span class="string">"dog"</span>));</span><br><span class="line"> System.out.println(context.getBean(<span class="string">"dog"</span>));</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-4"><p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitAppFactory.png" alt=""></p><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
<h3 id="第四种：使用-Import注解">第四种：使用@Import注解</h3>
<p>被导入的 Bean 不需要使用注解声明为 Bean，<strong>可以有效降低代码与 Spring 的耦合</strong>。</p>
<p>输出的结果为全路径类名：<em>com.bean.Dog</em>。</p>
<blockquote>
<p>也可以导入配置类，且被导入的配置类不需要使用 <code>@Configuration</code> 注解，配置类下声明的其他类也会被注入。</p>
</blockquote>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">配置类</button></li><li class="tab"><button type="button" data-href="#test4-2">Bean</button></li><li class="tab"><button type="button" data-href="#test4-3">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-4">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Import({Dog.class})</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">SpringConfig4</span> </span>{</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">Dog</span> </span>{</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App4</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> ApplicationContext context = <span class="keyword">new</span> AnnotationConfigApplicationContext(SpringConfig4.class);</span><br><span class="line"> String[] names = context.getBeanDefinitionNames();</span><br><span class="line"> <span class="keyword">for</span> (String name : names){</span><br><span class="line"> System.out.println(name);</span><br><span class="line"> }</span><br><span class="line"> System.out.println(context.getBean(Dog.class));</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-4"><p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp4.png" alt=""></p><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
<h3 id="第五种：上下文容器对象初始化完成后注入">第五种：上下文容器对象初始化完成后注入</h3>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">被注入的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-2">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-3">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Component("tom")</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">Cat</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="title">Cat</span><span class="params">()</span> </span>{</span><br><span class="line"></span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="keyword">private</span> <span class="keyword">int</span> age;</span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="title">Cat</span><span class="params">(<span class="keyword">int</span> age)</span> </span>{</span><br><span class="line"> <span class="keyword">this</span>.age = age;</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> String <span class="title">toString</span><span class="params">()</span> </span>{</span><br><span class="line"> <span class="keyword">return</span> <span class="string">"Cat{"</span> +</span><br><span class="line"> <span class="string">"age="</span> + age +</span><br><span class="line"> <span class="string">'}'</span>;</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App5</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> AnnotationConfigApplicationContext context = <span class="keyword">new</span> AnnotationConfigApplicationContext(SpringConfig4.class);</span><br><span class="line"></span><br><span class="line"> <span class="comment">// 上下文容器对象初始化完成后，手工加载 Bean，如果注册的 beanName 相同，只保留最后一个</span></span><br><span class="line"> context.registerBean(<span class="string">"tom"</span>, Cat.class, <span class="string">"1"</span>);</span><br><span class="line"> context.registerBean(<span class="string">"tom"</span>, Cat.class, <span class="string">"2"</span>);</span><br><span class="line"> context.registerBean(<span class="string">"tom"</span>, Cat.class, <span class="string">"3"</span>);</span><br><span class="line"> </span><br><span class="line"> <span class="comment">// 使用该方式声明，名称为类名小写</span></span><br><span class="line"> context.register(Mouse.class);</span><br><span class="line"></span><br><span class="line"> String[] names = context.getBeanDefinitionNames();</span><br><span class="line"> <span class="keyword">for</span> (String name : names) {</span><br><span class="line"> System.out.println(name);</span><br><span class="line"> }</span><br><span class="line"> System.out.println(context.getBean(<span class="string">"tom"</span>.toString()));</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp5.png" alt=""></p><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
<h3 id="⭐-第六种：实现ImportSelector接口">⭐| 第六种：实现ImportSelector接口</h3>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">实现 ImportSelector 接口</button></li><li class="tab"><button type="button" data-href="#test4-2">配置类</button></li><li class="tab"><button type="button" data-href="#test4-3">Bean</button></li><li class="tab"><button type="button" data-href="#test4-4">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-5">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MySelector</span> <span class="keyword">implements</span> <span class="title">ImportSelector</span> </span>{</span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="keyword">public</span> String[] selectImports(AnnotationMetadata annotationMetadata) {</span><br><span class="line"> <span class="comment">/**</span></span><br><span class="line"><span class="comment"> * 可以进行各种条件判断，判断完毕后，决定是否加载指定 Bean</span></span><br><span class="line"><span class="comment"> * 需要使用全路径类名（和 import 后的路径相同）。</span></span><br><span class="line"><span class="comment"> *</span></span><br><span class="line"><span class="comment"> * 谁导入这个类（MySelector），就检测哪个类（此处检测SpringConfig6）</span></span><br><span class="line"><span class="comment"> *</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">boolean</span> flag = annotationMetadata.hasAnnotation(Configuration.class.getName());</span><br><span class="line"> <span class="keyword">if</span> (flag) {</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">new</span> String[]{<span class="string">"com.bean.Dog"</span>};</span><br><span class="line"> }</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">new</span> String[]{<span class="string">"com.bean.Cat"</span>};</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Configuration</span></span><br><span class="line"><span class="meta">@Import({MySelector.class})</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">SpringConfig6</span> </span>{</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">Dog</span> </span>{</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="meta">@Component("tom")</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">Cat</span> </span>{</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-4"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App6</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> ApplicationContext context = <span class="keyword">new</span> AnnotationConfigApplicationContext(SpringConfig6.class);</span><br><span class="line"></span><br><span class="line"> String[] names = context.getBeanDefinitionNames();</span><br><span class="line"> <span class="keyword">for</span> (String name : names) {</span><br><span class="line"> System.out.println(name);</span><br><span class="line"> }</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-5"><ol>
<li>使用了<code>@Configuration</code> 注解<br>
<img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp6-1.png" alt=""></li>
<li>没有使用<code>@Configuration</code> 注解<br>
<img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp6-2.png" alt=""></li>
</ol><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
<h3 id="第七种：实现ImportBeanDefinitionRegistrar接口">第七种：实现ImportBeanDefinitionRegistrar接口</h3>
<p>通过 <em>BeanDefinition</em> 注册器注册实名 Bean，实现对容器中 Bean 的处理，例如：覆盖现有 Bean。</p>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">实现 ImportBeanDefinitionRegistrar 接口</button></li><li class="tab"><button type="button" data-href="#test4-2">配置类</button></li><li class="tab"><button type="button" data-href="#test4-3">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-4">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyRegistrar</span> <span class="keyword">implements</span> <span class="title">ImportBeanDefinitionRegistrar</span> </span>{</span><br><span class="line"></span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">registerBeanDefinitions</span><span class="params">(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry)</span> </span>{</span><br><span class="line"> <span class="comment">// 可以使用 元数据（importingClassMetadata） 做条件判断（参考方式5）</span></span><br><span class="line"> BeanDefinition beanDefinition = BeanDefinitionBuilder.rootBeanDefinition(Dog.class).getBeanDefinition();</span><br><span class="line"> registry.registerBeanDefinition(<span class="string">"yellow"</span>, beanDefinition);</span><br><span class="line"></span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Import({MyRegistrar.class})</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">SpringConfig7</span> </span>{</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App7</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> ApplicationContext context = <span class="keyword">new</span> AnnotationConfigApplicationContext(SpringConfig7.class);</span><br><span class="line"></span><br><span class="line"> String[] names = context.getBeanDefinitionNames();</span><br><span class="line"> <span class="keyword">for</span> (String name : names) {</span><br><span class="line"> System.out.println(name);</span><br><span class="line"> }</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-4"><p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp7.png" alt=""></p><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
<h3 id="第八种：后置处理器-PostProcessor">第八种：后置处理器 PostProcessor</h3>
<p>最后处理 Bean 的注册，可以保障兜底。</p>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">实现 ImportBeanDefinitionRegistrar 接口</button></li><li class="tab"><button type="button" data-href="#test4-2">BookService</button></li><li class="tab"><button type="button" data-href="#test4-3">BookServiceImpl1</button></li><li class="tab"><button type="button" data-href="#test4-4">BookServiceImpl2</button></li><li class="tab"><button type="button" data-href="#test4-5">BookServiceImpl3</button></li><li class="tab"><button type="button" data-href="#test4-6">BookServiceImpl4</button></li><li class="tab"><button type="button" data-href="#test4-7">MyRegistrar</button></li><li class="tab"><button type="button" data-href="#test4-8">MyRegistrar2</button></li><li class="tab"><button type="button" data-href="#test4-9">配置文件</button></li><li class="tab"><button type="button" data-href="#test4-10">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-11">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyPostProcessor</span> <span class="keyword">implements</span> <span class="title">BeanDefinitionRegistryPostProcessor</span> </span>{</span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">postProcessBeanDefinitionRegistry</span><span class="params">(BeanDefinitionRegistry beanDefinitionRegistry)</span> <span class="keyword">throws</span> BeansException </span>{</span><br><span class="line"> BeanDefinition beanDefinition = BeanDefinitionBuilder.rootBeanDefinition(BookServiceImpl4.class).getBeanDefinition();</span><br><span class="line"> beanDefinitionRegistry.registerBeanDefinition(<span class="string">"bookService"</span>, beanDefinition);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">postProcessBeanFactory</span><span class="params">(ConfigurableListableBeanFactory configurableListableBeanFactory)</span> <span class="keyword">throws</span> BeansException </span>{</span><br><span class="line"></span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">interface</span> <span class="title">BookService</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">void</span> <span class="title">check</span><span class="params">()</span></span>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Service("bookService")</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">BookServiceImpl1</span> <span class="keyword">implements</span> <span class="title">BookService</span> </span>{</span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">check</span><span class="params">()</span> </span>{</span><br><span class="line"> System.out.println(<span class="string">"book service 1.."</span>);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-4"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">BookServiceImpl2</span> <span class="keyword">implements</span> <span class="title">BookService</span> </span>{</span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">check</span><span class="params">()</span> </span>{</span><br><span class="line"> System.out.println(<span class="string">"book service 2...."</span>);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-5"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">BookServiceImpl3</span> <span class="keyword">implements</span> <span class="title">BookService</span> </span>{</span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">check</span><span class="params">()</span> </span>{</span><br><span class="line"> System.out.println(<span class="string">"book service 3......"</span>);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-6"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">BookServiceImpl4</span> <span class="keyword">implements</span> <span class="title">BookService</span> </span>{</span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">check</span><span class="params">()</span> </span>{</span><br><span class="line"> System.out.println(<span class="string">"book service 4........"</span>);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-7"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyRegistrar</span> <span class="keyword">implements</span> <span class="title">ImportBeanDefinitionRegistrar</span> </span>{</span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">registerBeanDefinitions</span><span class="params">(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry)</span> </span>{</span><br><span class="line"> BeanDefinition beanDefinition = BeanDefinitionBuilder.rootBeanDefinition(BookServiceImpl2.class).getBeanDefinition();</span><br><span class="line"> registry.registerBeanDefinition(<span class="string">"bookService"</span>, beanDefinition);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-8"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyRegistrar2</span> <span class="keyword">implements</span> <span class="title">ImportBeanDefinitionRegistrar</span> </span>{</span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">registerBeanDefinitions</span><span class="params">(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry)</span> </span>{</span><br><span class="line"> BeanDefinition beanDefinition = BeanDefinitionBuilder.rootBeanDefinition(BookServiceImpl3.class).getBeanDefinition();</span><br><span class="line"> registry.registerBeanDefinition(<span class="string">"bookService"</span>, beanDefinition);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-9"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Import({BookServiceImpl1.class, MyRegistrar.class, MyRegistrar2.class, MyPostProcessor.class})</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">SpringConfig8</span> </span>{</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-10"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App8</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> ApplicationContext context = <span class="keyword">new</span> AnnotationConfigApplicationContext(SpringConfig8.class);</span><br><span class="line"></span><br><span class="line"> BookService bookService = context.getBean(<span class="string">"bookService"</span>, BookService.class);</span><br><span class="line"> bookService.check();</span><br><span class="line"></span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-11"><p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp8.png" alt=""></p><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
<h2 id="Bean的加载控制">Bean的加载控制</h2>
<p>第五种 ~ 第八种 都支持根据条件加载 Bean，此处使用第五种方式做示例。</p>
<h3 id="编程式控制">编程式控制</h3>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">实现 ImportSelector 接口</button></li><li class="tab"><button type="button" data-href="#test4-2">Bean</button></li><li class="tab"><button type="button" data-href="#test4-3">配置文件</button></li><li class="tab"><button type="button" data-href="#test4-4">获取加载的 Bean</button></li><li class="tab"><button type="button" data-href="#test4-5">返回结果</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyImportSelector</span> <span class="keyword">implements</span> <span class="title">ImportSelector</span> </span>{</span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="keyword">public</span> String[] selectImports(AnnotationMetadata importingClassMetadata) {</span><br><span class="line"></span><br><span class="line"> <span class="comment">// 1. 假设当前加载了 Mouse 类，则加载 Cat，否则不加载</span></span><br><span class="line"> <span class="keyword">try</span> {</span><br><span class="line"> <span class="comment">// 加载 Mouse 类</span></span><br><span class="line"> Class cl = Class.forName(<span class="string">"com.bean.Mouse"</span>);</span><br><span class="line"> <span class="keyword">if</span> (cl != <span class="keyword">null</span>) {</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">new</span> String[]{<span class="string">"com.bean.Cat"</span>};</span><br><span class="line"> }</span><br><span class="line"> } <span class="keyword">catch</span> (ClassNotFoundException e) {</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">new</span> String[<span class="number">0</span>];</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">null</span>;</span><br><span class="line"></span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">Mouse</span> </span>{</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="meta">@Component("tom")</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">Cat</span> </span>{</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Import(MyImportSelector.class)</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">SpringConfig</span> </span>{</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-4"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">App</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> ApplicationContext context = <span class="keyword">new</span> AnnotationConfigApplicationContext(SpringConfig.class);</span><br><span class="line"> String[] beanNames = context.getBeanDefinitionNames();</span><br><span class="line"> <span class="keyword">for</span> (String name : beanNames) {</span><br><span class="line"> System.out.println(name);</span><br><span class="line"> }</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-5"><p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/BeanInitApp8.png" alt=""></p><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
<h3 id="注解控制（Condition）">注解控制（Condition）</h3>
<p>Spring 4.0 新增的条件判断功能，通过该功能可以实现选择性的创建 Bean 操作。</p>
<p>用于判断当前环境中是否导入相关类。</p>
<h4 id="问题：如何判断-Bean-注入成功？">问题：如何判断 Bean 注入成功？</h4>
<div class="tabs" id="test4"><ul class="nav-tabs"><li class="tab active"><button type="button" data-href="#test4-1">创建一个实体类</button></li><li class="tab"><button type="button" data-href="#test4-2">实现 Condition 接口并重写 *matches* 方法</button></li><li class="tab"><button type="button" data-href="#test4-3">新建注解，实现动态注入参数</button></li><li class="tab"><button type="button" data-href="#test4-4">创建 Config 类作为配置注入</button></li><li class="tab"><button type="button" data-href="#test4-5">修改启动类，输出创建的 Person 对象</button></li></ul><div class="tab-contents"><div class="tab-item-content active" id="test4-1"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">Person</span> </span>{</span><br><span class="line"> <span class="keyword">private</span> String name;</span><br><span class="line"> <span class="keyword">private</span> String age;</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="title">Person</span><span class="params">(String name, String age)</span> </span>{</span><br><span class="line"> <span class="keyword">this</span>.name = name;</span><br><span class="line"> <span class="keyword">this</span>.age = age;</span><br><span class="line"> }</span><br><span class="line"> <span class="comment">// 省去 getter/setter 和 toString() </span></span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-2"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">PersonConditional</span> <span class="keyword">implements</span> <span class="title">Condition</span> </span>{</span><br><span class="line"></span><br><span class="line"> <span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@param</span> context 上下文对象，用于获取环境、IOC容器、ClassLoader对象等</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@param</span> metadata 注解元对象，获取注解定义的属性值</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@return</span></span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"> <span class="meta">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">boolean</span> <span class="title">matches</span><span class="params">(ConditionContext context, AnnotatedTypeMetadata metadata)</span> </span>{</span><br><span class="line"> <span class="keyword">boolean</span> flag = <span class="keyword">true</span>;</span><br><span class="line"> Map<String, Object> map = metadata.getAnnotationAttributes(PersonConditionOnClass.class.getName());</span><br><span class="line"> String[] value = (String[]) map.get(<span class="string">"value"</span>);</span><br><span class="line"> <span class="keyword">try</span> {</span><br><span class="line"> <span class="keyword">for</span> (String className : value) {</span><br><span class="line"> Class<?> cls = Class.forName(className);</span><br><span class="line"> }</span><br><span class="line"> } <span class="keyword">catch</span> (ClassNotFoundException e) {</span><br><span class="line"> flag = <span class="keyword">false</span>;</span><br><span class="line"> }</span><br><span class="line"> <span class="keyword">return</span> flag;</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-3"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Target({ElementType.TYPE, ElementType.METHOD})</span></span><br><span class="line"><span class="meta">@Retention(RetentionPolicy.RUNTIME)</span></span><br><span class="line"><span class="meta">@Documented</span></span><br><span class="line"><span class="meta">@Conditional({PersonConditional.class})</span></span><br><span class="line"><span class="keyword">public</span> <span class="meta">@interface</span> PersonConditionOnClass {</span><br><span class="line"> String[] value();</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-4"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Configuration</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">PersonConfig</span> </span>{</span><br><span class="line"> <span class="comment">/**</span></span><br><span class="line"><span class="comment"> * <span class="doctag">@PersonConditionOnClass</span> 为自定义注解</span></span><br><span class="line"><span class="comment"> * 容器需要先加载 com.alibaba.fastjson.JSON 才会注入 Person 对象</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"> <span class="meta">@Bean</span></span><br><span class="line"> <span class="meta">@PersonConditionOnClass("com.alibaba.fastjson.JSON")</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> Person <span class="title">person</span><span class="params">()</span> </span>{</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">new</span> Person(<span class="string">"tom"</span>, <span class="string">"20"</span>);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div><div class="tab-item-content" id="test4-5"><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">TestApplication</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">main</span><span class="params">(String[] args)</span> </span>{</span><br><span class="line"> <span class="comment">// 启动 springboot 的容器，返回 spring 的 ioc 容器</span></span><br><span class="line"> ConfigurableApplicationContext context = SpringApplication.run(TestApplication.classargs);</span><br><span class="line"> Object object = context.getBean(<span class="string">"person"</span>);</span><br><span class="line"> System.out.println(object);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure><button type="button" class="tab-to-top" aria-label="scroll to top"><i class="fas fa-arrow-up"></i></button></div></div></div>
<h4 id="SpringBoot-自带的-Condition">SpringBoot 自带的 Condition</h4>
<p>路径为：<code>spring-boot-autoconfigure.jar \org\springframework\boot\autoconfigure\condition</code></p>
<p><img src="https://raw.githubusercontent.com/LazyLutra/imgBed/main/SpringbootAutoConfigureConditionExample.png" alt="示例"></p>
<h4 id="小结-2">小结</h4>
<ul>
<li>
<p>自定义条件流程</p>
<ol>
<li>创建类实现 Condition 接口并重写 matches 方法，并且在 matches 方法中进行判断，返回 boolean 值。
<ul>
<li>matches 方法有两个参数：
<ol>
<li>context：上下文对象，用于获取环境、IOC容器、ClassLoader对象等</li>
<li>metadata：注解元对象，获取注解定义的属性值</li>
</ol>
</li>
</ul>
</li>
<li>判断条件：<br>
在初始化 Bean 的时候，使用 <code>@Conditional({条件类.class})</code> 注解</li>
</ol>
</li>
<li>
<p>Springboot 提供了常用的条件注解</p>
<ol>
<li><code>@ConditionalOnClass</code>：判断环境中是否有对应的 class 文件，存在则初始化 Bean</li>
<li><code>@ConditionalOnProperty</code>： 判断配置文件是否有对应的属性和值，存在则初始化 Bean</li>
<li><code>@ConditionalOnMissingBean</code>：环境中如果不存在这个 Bean，则初始化</li>
</ol>
</li>
</ul>
<h2 id="依赖属性配置">依赖属性配置</h2>
<p>业务 Bean 尽量避免设置为强制加载，而是根据需要导入后加载，可以有效降低 Spring 容器管理 Bean 的强度。</p>
<p>将业务功能运行时所需的资源抽取出来独立成类（xxxProperties），读取配置文件信息。</p>
<p>而配置文件中使用固定格式为属性类注入数据。</p>
<p>定义业务功能 Bean，通常使用 <code>@Import</code> 导入，可以有效解耦。</p>
<p>使用 <code>@EnableConfigurationProperties</code> 注解，设置使用属性类时才加载 Bean。</p>
</article><div class="post-copyright"><div class="post-copyright__author"><span class="post-copyright-meta">文章作者: </span><span class="post-copyright-info"><a href="mailto:undefined">huy</a></span></div><div class="post-copyright__type"><span class="post-copyright-meta">文章链接: </span><span class="post-copyright-info"><a href="http://example.com/11802.html">http://example.com/11802.html</a></span></div><div class="post-copyright__notice"><span class="post-copyright-meta">版权声明: </span><span class="post-copyright-info">本博客所有文章除特别声明外，均采用 <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/" target="_blank">CC BY-NC-SA 4.0</a> 许可协议。转载请注明来自 <a href="http://example.com" target="_blank">征蓬</a>！</span></div></div><div class="tag_share"><div class="post-meta__tag-list"><a class="post-meta__tags" href="/tags/SpringBoot/">SpringBoot</a></div><div class="post_share"><div class="social-share" data-image="/pics/scenery/03.jpg" data-sites="facebook,twitter,wechat,weibo,qq"></div><link rel="stylesheet" href="https://jsdelivr.pai233.top/npm/social-share.js/dist/css/share.min.css" media="print" onload="this.media='all'"><script src="https://jsdelivr.pai233.top/npm/social-share.js/dist/js/social-share.min.js" defer></script></div></div><div class="relatedPosts"><div class="headline"><i class="fas fa-thumbs-up fa-fw"></i><span>相关推荐</span></div><div class="relatedPosts-list"><div><a href="/48587.html" title="SpringBoot（一）：日志框架配置"><img class="cover" src="/pics/scenery/03.jpg" alt="cover"><div class="content is-center"><div class="date"><i class="far fa-calendar-alt fa-fw"></i> 2021-01-29</div><div class="title">SpringBoot（一）：日志框架配置</div></div></a></div><div><a href="/35740.html" title="SpringBoot（七）：Application文件配置"><img class="cover" src="/pics/scenery/01.jpg" alt="cover"><div class="content is-center"><div class="date"><i class="far fa-calendar-alt fa-fw"></i> 2022-01-20</div><div class="title">SpringBoot（七）：Application文件配置</div></div></a></div><div><a href="/23140.html" title="SpringBoot（三）：数据库"><img class="cover" src="/pics/scenery/18.jpg" alt="cover"><div class="content is-center"><div class="date"><i class="far fa-calendar-alt fa-fw"></i> 2021-02-10</div><div class="title">SpringBoot（三）：数据库</div></div></a></div><div><a href="/3737.html" title="SpringBoot（五）：Swagger2配置和服务器部署"><img class="cover" src="/pics/scenery/15.jpg" alt="cover"><div class="content is-center"><div class="date"><i class="far fa-calendar-alt fa-fw"></i> 2021-12-09</div><div class="title">SpringBoot（五）：Swagger2配置和服务器部署</div></div></a></div><div><a href="/4811.html" title="SpringBoot（八）：Thymeleaf基础功能"><img class="cover" src="/pics/scenery/03.jpg" alt="cover"><div class="content is-center"><div class="date"><i class="far fa-calendar-alt fa-fw"></i> 2022-02-03</div><div class="title">SpringBoot（八）：Thymeleaf基础功能</div></div></a></div><div><a href="/44660.html" title="SpringBoot（六）：常见问题"><img class="cover" src="/pics/scenery/29.jpg" alt="cover"><div class="content is-center"><div class="date"><i class="far fa-calendar-alt fa-fw"></i> 2021-12-23</div><div class="title">SpringBoot（六）：常见问题</div></div></a></div></div></div></div><div class="aside-content" id="aside-content"><div class="sticky_layout"><div class="card-widget" id="card-toc"><div class="item-headline"><i class="fas fa-stream"></i><span>目录</span></div><div class="toc-content"><ol class="toc"><li class="toc-item toc-level-2"><a class="toc-link" href="#Bean%E7%9A%84%E5%8A%A0%E8%BD%BD%E6%96%B9%E5%BC%8F"><span class="toc-number">1.</span> <span class="toc-text">Bean的加载方式</span></a><ol class="toc-child"><li class="toc-item toc-level-3"><a class="toc-link" href="#%E7%AC%AC%E4%B8%80%E7%A7%8D%EF%BC%9AXML"><span class="toc-number">1.1.</span> <span class="toc-text">第一种：XML</span></a></li><li class="toc-item toc-level-3"><a class="toc-link" href="#%E7%AC%AC%E4%BA%8C%E7%A7%8D%EF%BC%9A%E6%B3%A8%E8%A7%A3"><span class="toc-number">1.2.</span> <span class="toc-text">第二种：注解</span></a><ol class="toc-child"><li class="toc-item toc-level-4"><a class="toc-link" href="#%E8%87%AA%E5%AE%9A%E4%B9%89-Bean"><span class="toc-number">1.2.1.</span> <span class="toc-text">自定义 Bean</span></a></li><li class="toc-item toc-level-4"><a class="toc-link" href="#%E7%AC%AC%E4%B8%89%E6%96%B9-Bean"><span class="toc-number">1.2.2.</span> <span class="toc-text">第三方 Bean</span></a></li></ol></li><li class="toc-item toc-level-3"><a class="toc-link" href="#%E7%AC%AC%E4%B8%89%E7%A7%8D%EF%BC%9A%E9%85%8D%E7%BD%AE%E7%B1%BB%E5%92%8CFactoryBean"><span class="toc-number">1.3.</span> <span class="toc-text">第三种：配置类和FactoryBean</span></a><ol class="toc-child"><li class="toc-item toc-level-4"><a class="toc-link" href="#%E9%85%8D%E7%BD%AE%E7%B1%BB"><span class="toc-number">1.3.1.</span> <span class="toc-text">配置类</span></a></li><li class="toc-item toc-level-4"><a class="toc-link" href="#FactoryBean"><span class="toc-number">1.3.2.</span> <span class="toc-text">FactoryBean</span></a></li></ol></li><li class="toc-item toc-level-3"><a class="toc-link" href="#%E7%AC%AC%E5%9B%9B%E7%A7%8D%EF%BC%9A%E4%BD%BF%E7%94%A8-Import%E6%B3%A8%E8%A7%A3"><span class="toc-number">1.4.</span> <span class="toc-text">第四种：使用@Import注解</span></a></li><li class="toc-item toc-level-3"><a class="toc-link" href="#%E7%AC%AC%E4%BA%94%E7%A7%8D%EF%BC%9A%E4%B8%8A%E4%B8%8B%E6%96%87%E5%AE%B9%E5%99%A8%E5%AF%B9%E8%B1%A1%E5%88%9D%E5%A7%8B%E5%8C%96%E5%AE%8C%E6%88%90%E5%90%8E%E6%B3%A8%E5%85%A5"><span class="toc-number">1.5.</span> <span class="toc-text">第五种：上下文容器对象初始化完成后注入</span></a></li><li class="toc-item toc-level-3"><a class="toc-link" href="#%E2%AD%90-%E7%AC%AC%E5%85%AD%E7%A7%8D%EF%BC%9A%E5%AE%9E%E7%8E%B0ImportSelector%E6%8E%A5%E5%8F%A3"><span class="toc-number">1.6.</span> <span class="toc-text">⭐| 第六种：实现ImportSelector接口</span></a></li><li class="toc-item toc-level-3"><a class="toc-link" href="#%E7%AC%AC%E4%B8%83%E7%A7%8D%EF%BC%9A%E5%AE%9E%E7%8E%B0ImportBeanDefinitionRegistrar%E6%8E%A5%E5%8F%A3"><span class="toc-number">1.7.</span> <span class="toc-text">第七种：实现ImportBeanDefinitionRegistrar接口</span></a></li><li class="toc-item toc-level-3"><a class="toc-link" href="#%E7%AC%AC%E5%85%AB%E7%A7%8D%EF%BC%9A%E5%90%8E%E7%BD%AE%E5%A4%84%E7%90%86%E5%99%A8-PostProcessor"><span class="toc-number">1.8.</span> <span class="toc-text">第八种：后置处理器 PostProcessor</span></a></li></ol></li><li class="toc-item toc-level-2"><a class="toc-link" href="#Bean%E7%9A%84%E5%8A%A0%E8%BD%BD%E6%8E%A7%E5%88%B6"><span class="toc-number">2.</span> <span class="toc-text">Bean的加载控制</span></a><ol class="toc-child"><li class="toc-item toc-level-3"><a class="toc-link" href="#%E7%BC%96%E7%A8%8B%E5%BC%8F%E6%8E%A7%E5%88%B6"><span class="toc-number">2.1.</span> <span class="toc-text">编程式控制</span></a></li><li class="toc-item toc-level-3"><a class="toc-link" href="#%E6%B3%A8%E8%A7%A3%E6%8E%A7%E5%88%B6%EF%BC%88Condition%EF%BC%89"><span class="toc-number">2.2.</span> <span class="toc-text">注解控制（Condition）</span></a><ol class="toc-child"><li class="toc-item toc-level-4"><a class="toc-link" href="#%E9%97%AE%E9%A2%98%EF%BC%9A%E5%A6%82%E4%BD%95%E5%88%A4%E6%96%AD-Bean-%E6%B3%A8%E5%85%A5%E6%88%90%E5%8A%9F%EF%BC%9F"><span class="toc-number">2.2.1.</span> <span class="toc-text">问题：如何判断 Bean 注入成功？</span></a></li><li class="toc-item toc-level-4"><a class="toc-link" href="#SpringBoot-%E8%87%AA%E5%B8%A6%E7%9A%84-Condition"><span class="toc-number">2.2.2.</span> <span class="toc-text">SpringBoot 自带的 Condition</span></a></li><li class="toc-item toc-level-4"><a class="toc-link" href="#%E5%B0%8F%E7%BB%93-2"><span class="toc-number">2.2.3.</span> <span class="toc-text">小结</span></a></li></ol></li></ol></li><li class="toc-item toc-level-2"><a class="toc-link" href="#%E4%BE%9D%E8%B5%96%E5%B1%9E%E6%80%A7%E9%85%8D%E7%BD%AE"><span class="toc-number">3.</span> <span class="toc-text">依赖属性配置</span></a></li></ol></div></div></div></div></main><footer id="footer" style="background-image: url('/pics/scenery/03.jpg')"><div id="footer-wrap"><div class="copyright">©2021 - 2022 By huy</div><div class="framework-info"><span>框架 </span><a target="_blank" rel="noopener" href="https://hexo.io">Hexo</a><span class="footer-separator">|</span><span>主题 </span><a target="_blank" rel="noopener" href="https://github.com/jerryc127/hexo-theme-butterfly">Butterfly</a></div></div></footer></div><div id="rightside"><div id="rightside-config-hide"><button id="readmode" type="button" title="阅读模式"><i class="fas fa-book-open"></i></button><button id="darkmode" type="button" title="浅色和深色模式转换"><i class="fas fa-adjust"></i></button><button id="hide-aside-btn" type="button" title="单栏和双栏切换"><i class="fas fa-arrows-alt-h"></i></button></div><div id="rightside-config-show"><button id="rightside_config" type="button" title="设置"><i class="fas fa-cog fa-spin"></i></button><button class="close" id="mobile-toc-button" type="button" title="目录"><i class="fas fa-list-ul"></i></button><button id="go-up" type="button" title="回到顶部"><i class="fas fa-arrow-up"></i></button></div></div><div id="local-search"><div class="search-dialog"><div class="search-dialog__title" id="local-search-title">本地搜索</div><div id="local-input-panel"><div id="local-search-input"><div class="local-search-box"><input class="local-search-box--input" placeholder="搜索文章" type="text"/></div></div></div><hr/><div id="local-search-results"></div><span class="search-close-button"><i class="fas fa-times"></i></span></div><div id="search-mask"></div></div><div><script src="/js/utils.js"></script><script src="/js/main.js"></script><script src="https://lf26-cdn-tos.bytecdntp.com/cdn/expire-1-M/node-snackbar/0.1.16/snackbar.min.js"></script><script src="/js/search/local-search.js"></script><div class="js-pjax"></div><script defer="defer" id="ribbon" src="https://jsdelivr.pai233.top/npm/butterfly-extsrc@1/dist/canvas-ribbon.min.js" size="150" alpha="0.6" zIndex="-1" mobile="false" data-click="false"></script><script id="click-heart" src="https://jsdelivr.pai233.top/npm/butterfly-extsrc@1/dist/click-heart.min.js" async="async" mobile="false"></script></div><!-- hexo injector body_end start --><script async src="//at.alicdn.com/t/font_2032782_8d5kxvn09md.js"></script><!-- hexo injector body_end end --></body></html>