<p>1. 首先是在struts2的工程里添加struts2-json-plugin.xxx.jar库，如果是使用的maven，添加以下dependency</p>    <p> </p>    <p></p>    <pre class="brush:xml; toolbar: true; auto-links: false;"> <dependency>   <groupId>org.apache.struts</groupId>   <artifactId>struts2-json-plugin</artifactId>   <version>2.1.8.1</version>  </dependency></pre>     <p></p>    <p> </p>    <p> </p>    <p>2. 创建Action类和一个用到的User类</p>    <p>Action类内容</p>    <p></p>    <pre class="brush:java; toolbar: true; auto-links: false;">import com.opensymphony.xwork2.Action; import java.util.ArrayList; import java.util.LinkedHashMap; import java.util.List; import java.util.Map; public class JSONExample2 {  private List<User> userList = new ArrayList<User>();  private Map<String, User> userMap = new LinkedHashMap<String, User>();  public String getMyUserList() {   for (int i = 0; i < 3; i++) {    User user = new User("id_" + i, "username_" + i, "password_" + i, "desc_" + i);    userList.add(user);   }   return Action.SUCCESS;  }  public String getMyUserMap() {   for (int i = 0; i < 3; i++) {    User user = new User("id_" + i, "username_" + i, "password_" + i, "desc_" + i);    userMap.put(user.getId(), user);   }   return Action.SUCCESS;  }  public List<User> getUserList() {   return userList;  }  public void setUserList(List<User> userList) {   this.userList = userList;  }  public Map<String, User> getUserMap() {   return userMap;  }  public void setUserMap(Map<String, User> userMap) {   this.userMap = userMap;  } }</pre>     <p></p>    <p> </p>    <p> </p>    <p>User类内容</p>    <p></p>    <pre class="brush:java; toolbar: true; auto-links: false;">import java.io.Serializable; public class User implements Serializable {  private static final long serialVersionUID = 1L;    private String id;  private String username;  private String password;  private String description;    public User() {  }  public User(String id, String username, String password, String description) {   this.id = id;   this.username = username;   this.password = password;   this.description = description;  }    public String getId() {   return id;  }  public void setId(String id) {   this.id = id;  }  public String getUsername() {   return username;  }  public void setUsername(String username) {   this.username = username;  }    public String getPassword() {   return password;  }  public void setPassword(String password) {   this.password = password;  }    public String getDescription() {   return description;  }  public void setDescription(String description) {   this.description = description;  } }</pre>     <p></p>    <p> </p>    <p>3. Spring配置文件</p>    <p></p>    <pre class="brush:java; toolbar: true; auto-links: false;"><?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"        xmlns:aop="http://www.springframework.org/schema/aop"        xmlns:lang="http://www.springframework.org/schema/lang"        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd                            http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd                            http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-2.0.xsd"        default-lazy-init="true">  <bean id="jsonExample2" class="JSONExample2" scope="prototype"/> </beans></pre>     <p></p>    <p> </p>    <p>4. Struts2配置文件</p>    <p></p>    <pre class="brush:java; toolbar: true; auto-links: false;"><?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" "http://struts.apache.org/dtds/struts-2.0.dtd"> <struts>    <include file="struts-default.xml" />  <package name="json" namespace="/json" extends="struts-default" >      <result-types>    <result-type name="json" class="org.apache.struts2.json.JSONResult"/>   </result-types>      <interceptors>    <interceptor name="json" class="org.apache.struts2.json.JSONInterceptor"/>   </interceptors>   <action name="getMyUserList" class="jsonExample2" method="getMyUserList">    <result type="json">     <param name="root">userList</param>    </result>   </action>   <action name="getMyUserMap" class="jsonExample2" method="getMyUserMap">    <result type="json">      <param name="root">userMap</param>    </result>   </action>  </package> </struts></pre>     <p></p>    <p> </p>    <p>5. 新建一个jsp文件json.jsp用来做测试</p>    <p></p>    <pre class="brush:xml; toolbar: true; auto-links: false;"><html>  <head>   <title></title>   <mce:script type="text/javascript" src="http://www.google.com/jsapi?key=helloworld" mce_src="http://www.google.com/jsapi?key=helloworld"></mce:script>   <mce:script type="text/javascript"><!--    google.load("jquery", "1.4.1");        function getMyUserList() {     var url = 'json/getMyUserList.action';     var params = {     };     jQuery.post(url, params, function(data) {      var s = "";      for (var idx = 0; idx < data.length; idx++) {       s += "user["+idx+"].id=" + data[idx].id + "/n";      }      alert(s);     }, 'json');    }    function getMyUserMap() {     var url = 'json/getMyUserMap.action';     var params = {     };     jQuery.post(url, params, function(data) {      var s = "";      for (var o in data) {       s += "user.id=" + data[o].id + ",";       s += "user.username=" + data[o].username + "/n";      }      alert(s);     }, 'json');    }    // --></mce:script>  </head>  <body style="margin: 20px;" mce_style="margin: 20px;">   <h3>json test</h3>   <ul>    <li><a href="#" mce_href="#" onclick="getMyUserList()">getMyUserList</a></li>    <li><a href="#" mce_href="#" onclick="getMyUserMap()">getMyUserMap</a></li>   </ul>  </body> </html></pre>     <p></p>    <p> </p>    <p> </p>    <p>6. 启动web容器测试，可以使用Tomcat或者maven自带的jetty，然后访问</p>    <p>  http://localhost:8080/json/json.jsp</p>    <p>  此时可以点击页面上的两个链接来测试结果。</p>    <p> </p>    <p>参考：https://cwiki.apache.org/confluence/display/WW/JSON%20Plugin</p>    <p> </p>