Merge pull request square#2935 from square/jwilson.1022.slack_client_…

…example

A WebSockets sample that uses the Slack API.

checkstyle.xml

@@ -4,6 +4,7 @@
     "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
 
 <module name="Checker">
+  <module name="SuppressWarningsFilter"/>
   <module name="NewlineAtEndOfFile"/>
   <module name="FileLength"/>
   <module name="FileTabCharacter"/>
@@ -139,5 +140,8 @@
     <!--module name="FinalParameters"/-->
     <!--module name="TodoComment"/-->
     <module name="UpperEll"/>
+
+    <!-- Make the @SuppressWarnings annotations available to Checkstyle -->
+    <module name="SuppressWarningsHolder"/>
   </module>
 </module>

pom.xml

@@ -193,7 +193,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-checkstyle-plugin</artifactId>
-        <version>2.10</version>
+        <version>2.12</version>
         <configuration>
           <failsOnError>true</failsOnError>
           <configLocation>checkstyle.xml</configLocation>

samples/pom.xml

@@ -18,6 +18,7 @@
     <module>guide</module>
     <module>crawler</module>
     <module>simple-client</module>
+    <module>slack</module>
     <module>static-server</module>
   </modules>
 

samples/slack/pom.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>com.squareup.okhttp3.sample</groupId>
+    <artifactId>sample-parent</artifactId>
+    <version>3.5.0-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>slack</artifactId>
+  <name>Sample: Slack</name>
+
+  <dependencies>
+    <dependency>
+      <groupId>com.squareup.okhttp3</groupId>
+      <artifactId>mockwebserver</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>com.squareup.moshi</groupId>
+      <artifactId>moshi</artifactId>
+    </dependency>
+  </dependencies>
+</project>

samples/slack/src/main/java/okhttp3/slack/OAuthSession.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2016 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package okhttp3.slack;
+
+/** Authorization for an application to make Slack API calls on behalf of a user. */
+@SuppressWarnings("checkstyle:membername")
+public final class OAuthSession {
+  public final boolean ok;
+  public final String access_token;
+  public final String scope;
+  public final String user_id;
+  public final String team_name;
+  public final String team_id;
+
+  public OAuthSession(
+      boolean ok, String accessToken, String scope, String userId, String teamName, String teamId) {
+    this.ok = ok;
+    this.access_token = accessToken;
+    this.scope = scope;
+    this.user_id = userId;
+    this.team_name = teamName;
+    this.team_id = teamId;
+  }
+
+  @Override public String toString() {
+    return String.format("(ok=%s, access_token=%s, scope=%s, user_id=%s, team_name=%s, team_id=%s)",
+        ok, access_token, scope, user_id, team_name, team_id);
+  }
+}

samples/slack/src/main/java/okhttp3/slack/OAuthSessionFactory.java

@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2016 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package okhttp3.slack;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.security.SecureRandom;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import okhttp3.HttpUrl;
+import okhttp3.mockwebserver.Dispatcher;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.MockWebServer;
+import okhttp3.mockwebserver.RecordedRequest;
+import okio.ByteString;
+
+/**
+ * Runs a MockWebServer on localhost and uses it as the backend to receive an OAuth session.
+ *
+ * <p>Clients should call {@link #start}, {@link #newAuthorizeUrl} and {@link #close} in that order.
+ * Clients may request multiple sessions.
+ */
+public final class OAuthSessionFactory extends Dispatcher implements Closeable {
+  private final SecureRandom secureRandom = new SecureRandom();
+
+  private final SlackApi slackApi;
+  private MockWebServer mockWebServer;
+
+  /** Guarded by this. */
+  private Map<ByteString, Listener> listeners = new LinkedHashMap<>();
+
+  public OAuthSessionFactory(SlackApi slackApi) {
+    this.slackApi = slackApi;
+  }
+
+  public void start() throws Exception {
+    if (mockWebServer != null) throw new IllegalStateException();
+
+    mockWebServer = new MockWebServer();
+    mockWebServer.setDispatcher(this);
+    mockWebServer.start(slackApi.port);
+  }
+
+  public HttpUrl newAuthorizeUrl(String scopes, String team, Listener listener) {
+    if (mockWebServer == null) throw new IllegalStateException();
+
+    ByteString state = randomToken();
+    synchronized (this) {
+      listeners.put(state, listener);
+    }
+
+    return slackApi.authorizeUrl(scopes, redirectUrl(), state, team);
+  }
+
+  private ByteString randomToken() {
+    byte[] bytes = new byte[16];
+    secureRandom.nextBytes(bytes);
+    return ByteString.of(bytes);
+  }
+
+  private HttpUrl redirectUrl() {
+    return mockWebServer.url("/oauth/");
+  }
+
+  /** When the browser hits the redirect URL, use the provied code to ask Slack for a session. */
+  @Override public MockResponse dispatch(RecordedRequest request) throws InterruptedException {
+    HttpUrl requestUrl = mockWebServer.url(request.getPath());
+    String code = requestUrl.queryParameter("code");
+    String stateString = requestUrl.queryParameter("state");
+    ByteString state = stateString != null ? ByteString.decodeBase64(stateString) : null;
+
+    Listener listener;
+    synchronized (this) {
+      listener = listeners.get(state);
+    }
+
+    if (code == null || listener == null) {
+      return new MockResponse()
+          .setResponseCode(404)
+          .setBody("unexpected request");
+    }
+
+    try {
+      OAuthSession session = slackApi.exchangeCode(code, redirectUrl());
+      listener.sessionGranted(session);
+    } catch (IOException e) {
+      return new MockResponse()
+          .setResponseCode(400)
+          .setBody("code exchange failed: " + e.getMessage());
+    }
+
+    synchronized (this) {
+      listeners.remove(state);
+    }
+
+    // Success!
+    return new MockResponse()
+        .setResponseCode(302)
+        .addHeader("Location", "https://twitter.com/CuteEmergency/status/789457462864863232");
+  }
+
+  public interface Listener {
+    void sessionGranted(OAuthSession session);
+  }
+
+  @Override public void close() {
+    if (mockWebServer == null) throw new IllegalStateException();
+    try {
+      mockWebServer.close();
+    } catch (IOException ignored) {
+    }
+  }
+}

samples/slack/src/main/java/okhttp3/slack/RtmSession.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2016 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package okhttp3.slack;
+
+import java.io.Closeable;
+import java.io.IOException;
+import okhttp3.Response;
+import okhttp3.ResponseBody;
+import okhttp3.WebSocket;
+import okhttp3.WebSocketCall;
+import okhttp3.WebSocketListener;
+import okio.ByteString;
+
+/** A realtime messaging session. */
+public final class RtmSession implements WebSocketListener, Closeable {
+  private final SlackApi slackApi;
+  private WebSocketCall webSocketCall;
+
+  /** Guarded by this. */
+  private WebSocket webSocket;
+
+  public RtmSession(SlackApi slackApi) {
+    this.slackApi = slackApi;
+  }
+
+  public void open(String accessToken) throws IOException {
+    if (webSocketCall != null) throw new IllegalStateException();
+
+    RtmStartResponse rtmStartResponse = slackApi.rtmStart(accessToken);
+    webSocketCall = slackApi.rtm(rtmStartResponse.url);
+    webSocketCall.enqueue(this);
+  }
+
+  // TODO(jwilson): can I read the response body? Do I have to?
+  //                the body from slack is a 0-byte-buffer
+  @Override public synchronized void onOpen(WebSocket webSocket, Response response) {
+    System.out.println("onOpen: " + response);
+    this.webSocket = webSocket;
+  }
+
+  // TOOD(jwilson): decode incoming messages and dispatch them somewhere.
+  @Override public void onMessage(ResponseBody message) throws IOException {
+    System.out.println("onMessage: " + message.string());
+  }
+
+  @Override public void onPong(ByteString payload) {
+    System.out.println("onPong: " + payload);
+  }
+
+  @Override public void onClose(int code, String reason) {
+    System.out.println("onClose (" + code + "): " + reason);
+  }
+
+  // TODO(jwilson): can I read the response body? Do I have to?
+  @Override public void onFailure(Throwable t, Response response) {
+    System.out.println("onFailure " + response);
+  }
+
+  @Override public void close() throws IOException {
+    if (webSocketCall == null) return;
+
+    WebSocket webSocket;
+    synchronized (this) {
+      webSocket = this.webSocket;
+    }
+
+    // TODO(jwilson): Racy? Is there an interleaving of events where the websocket is not closed?
+    //                Our docs say we can’t close if we have an active writer: that seems like it
+    //                could cause problems?
+    if (webSocket != null) {
+      webSocket.close(1000, "bye");
+    } else {
+      webSocketCall.cancel();
+    }
+  }
+}

samples/slack/src/main/java/okhttp3/slack/RtmStartResponse.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2016 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package okhttp3.slack;
+
+import java.util.List;
+import okhttp3.HttpUrl;
+
+/** See https://api.slack.com/methods/rtm.start. */
+public final class RtmStartResponse {
+  HttpUrl url;
+  Object self;
+  Object team;
+  List<Object> users;
+  List<Object> channels;
+  List<Object> groups;
+  List<Object> mpims;
+  List<Object> ims;
+  List<Object> bots;
+}