Manage pagination

pom.xml

@@ -119,23 +119,10 @@
                 </executions>
             </plugin>
 
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-gpg-plugin</artifactId>
-                <version>1.6</version>
-                <configuration>
-                    <useAgent>true</useAgent>
-                </configuration>
-                <executions>
-                    <execution>
-                        <id>sign-artifacts</id>
-                        <phase>verify</phase>
-                        <goals>
-                            <goal>sign</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
+           <plugin>
+             <groupId>org.simplify4u.plugins</groupId>
+             <artifactId>sign-maven-plugin</artifactId>
+           </plugin>
 
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -154,8 +141,17 @@
                     <autoReleaseAfterClose>true</autoReleaseAfterClose>
                 </configuration>
             </plugin>
-
         </plugins>
+
+        <pluginManagement>
+          <plugins>
+          	<plugin>
+              <groupId>org.simplify4u.plugins</groupId>
+              <artifactId>sign-maven-plugin</artifactId>
+              <version>0.3.1</version>
+            </plugin>
+          </plugins>
+        </pluginManagement>
     </build>
 
 </project>

src/main/java/com/icoderman/woocommerce/DefaultHttpClient.java

@@ -1,7 +1,12 @@
 package com.icoderman.woocommerce;
 
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.ObjectMapper;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
 import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
 import org.apache.http.NameValuePair;
@@ -18,16 +23,15 @@
 import org.apache.http.impl.client.HttpClientBuilder;
 import org.apache.http.message.BasicNameValuePair;
 
-import java.io.IOException;
-import java.net.URISyntaxException;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
 
 public class DefaultHttpClient implements HttpClient {
 
     private static final String CONTENT_TYPE = "Content-Type";
     private static final String APPLICATION_JSON = "application/json";
+    private static final String WC_TOTAL_HEADER = "X-WP-Total";
+    private static final String WC_TOTAL_PAGES_HEADER = "X-WP-TotalPages";
 
     private CloseableHttpClient httpClient;
     private ObjectMapper mapper;
@@ -44,9 +48,14 @@ public Map get(String url) {
     }
 
     @Override
-    public List getAll(String url) {
+    public Page getAll(String url) {
         HttpGet httpGet = new HttpGet(url);
-        return getEntityAndReleaseConnection(httpGet, List.class);
+        Map result = getEntityWithHeaderAndReleaseConnection(httpGet, List.class);
+        List content =  (List) result.get("content");
+        int total = Integer.parseInt(result.get("total").toString());
+        int totalPages = Integer.parseInt(result.get("totalPages").toString());
+        Page page = new Page<>(content, total, totalPages, content.size());
+        return page;
     }
 
     @Override
@@ -131,4 +140,29 @@ private <T> T getEntityAndReleaseConnection(HttpRequestBase httpRequest, Class<T
             httpRequest.releaseConnection();
         }
     }
+
+    private <T> Map getEntityWithHeaderAndReleaseConnection(HttpRequestBase httpRequest, Class<T> objectClass) {
+        try {
+            HttpResponse httpResponse = httpClient.execute(httpRequest);
+            HttpEntity httpEntity = httpResponse.getEntity();
+            if (httpEntity == null) {
+                throw new RuntimeException("Error retrieving results from http request");
+            }
+            Object result = mapper.readValue(httpEntity.getContent(), Object.class);
+            if (objectClass.isInstance(result)) {
+            	Map<String, Object> map = new HashMap<>();
+            	if (httpResponse.containsHeader(WC_TOTAL_HEADER)) {
+            		map.put("total", httpResponse.getFirstHeader(WC_TOTAL_HEADER).getValue());
+            		map.put("totalPages", httpResponse.getFirstHeader(WC_TOTAL_PAGES_HEADER).getValue());            		
+            	}
+            	map.put("content", objectClass.cast(result));
+                return map;
+            }
+            throw new RuntimeException("Can't parse retrieved object: " + result.toString());
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        } finally {
+            httpRequest.releaseConnection();
+        }
+    }
 }

src/main/java/com/icoderman/woocommerce/HttpClient.java

@@ -1,6 +1,5 @@
 package com.icoderman.woocommerce;
 
-import java.util.List;
 import java.util.Map;
 
 /**
@@ -22,7 +21,7 @@ public interface HttpClient {
      * @param url url to request
      * @return retrieved result
      */
-    List getAll(String url);
+    Page getAll(String url);
 
     /**
      * Requests url with HTTP POST and retrieves result object as Map

src/main/java/com/icoderman/woocommerce/Page.java

@@ -0,0 +1,53 @@
+package com.icoderman.woocommerce;
+
+import java.util.List;
+
+public class Page<T> {
+
+	/**
+	 * List of element.
+	 */
+	private List<T> content;
+	/**
+	 * Total number of element.
+	 */
+	private int total;
+	/**
+	 * Total number of pages.
+	 */
+	private int totalPages;
+	/**
+	 * Size of the current page.
+	 */
+	private int size;
+
+	/**
+	 * Create new page of element.
+	 * @param content Content list
+	 * @param total total number of element.
+	 * @param totalPages total number of pages.
+	 * @param size size of the current result.
+	 */
+	public Page(List<T> content, int total, int totalPages, int size) {
+		this.content = content;
+		this.total = total;
+		this.totalPages = totalPages;
+		this.size = size;
+	}
+
+	public List<T> getContent() {
+		return content;
+	}
+
+	public int getTotal() {
+		return total;
+	}
+
+	public int getTotalPages() {
+		return totalPages;
+	}
+
+	public int getSize() {
+		return size;
+	}
+}

src/main/java/com/icoderman/woocommerce/WooCommerce.java

@@ -34,15 +34,15 @@ public interface WooCommerce {
      * @param params additional request params
      * @return List of retrieved entities
      */
-    List getAll(String endpointBase, Map<String, String> params);
+    Page getAll(String endpointBase, Map<String, String> params);
 
     /**
      * Retrieves all WooCommerce entities
      *
      * @param endpointBase API endpoint base @see EndpointBaseType
      * @return List of retrieved entities
      */
-    default List getAll(String endpointBase) {
+    default Page getAll(String endpointBase) {
         return getAll(endpointBase, Collections.emptyMap());
     }
 

src/main/java/com/icoderman/woocommerce/WooCommerceAPI.java

@@ -38,7 +38,7 @@ public Map get(String endpointBase, int id) {
     }
 
     @Override
-    public List getAll(String endpointBase, Map<String, String> params) {
+    public Page getAll(String endpointBase, Map<String, String> params) {
         String url = String.format(API_URL_FORMAT, config.getUrl(), apiVersion, endpointBase);
         String signature = OAuthSignature.getAsQueryString(config, url, HttpMethod.GET, params);
         String securedUrl = String.format(URL_SECURED_FORMAT, url, signature);