struts2-json-plugin插件实现异步通信

用例需要依赖的jar：

1. struts2-core.jar
2. struts2-convention-plugin.jar，非必须，
3. struts2-json-plugin.jar
4. org.codehaus.jackson.jar，提供json支持

用例代码如下：

• 数据库DDL语句

无

• struts.xml

 <?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>
     <package name="basePackage" extends="json-default">
         <!-- 未到找Action指向页面 -->
         <default-action-ref name="404" />

         <global-exception-mappings>
             <exception-mapping result="exception" exception="java.lang.Exception"></exception-mapping>
         </global-exception-mappings>

         <action name="404">
             <result type="dispatcher">/WEB-INF/jsp/error/error_page_404.jsp</result>
         </action>
     </package>

     <!-- 入口地址：http://localhost:8888/struts2-test/test/gotoStruts2JsonPlugin.action -->
     <package name="ajax" namespace="/test" extends="basePackage">
         <action name="struts2JsonPlugin" method="struts2JsonPlugin"
             class="test.action.ajax.Struts2JsonPluginAction">
             <result type="json">
                 <!-- 指定浏览器不缓存服务器响应 -->
                 <param name="noCache">true</param>
                 <!-- 指定不包括Action中值为null的属性 -->
                 <param name="excludeNullProperties">true</param>
             </result>
         </action>
     </package>
 </struts>

• java类

action类

BaseAction.java

 package test.util;
 import java.io.IOException;
 import java.io.StringWriter;
 import java.io.Writer;
 import java.util.HashMap;
 import java.util.Map;
 import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import org.apache.log4j.Logger;
 import org.apache.struts2.ServletActionContext;
 import org.codehaus.jackson.JsonGenerator;
 import org.codehaus.jackson.JsonProcessingException;
 import org.codehaus.jackson.map.ObjectMapper;
 import com.opensymphony.xwork2.ActionSupport;

 public class BaseAction extends ActionSupport {

     private static final long serialVersionUID = 4271951142973483943L;

     protected Logger logger = Logger.getLogger(getClass());

     // 获取Attribute
     public Object getAttribute(String name) {
         return ServletActionContext.getRequest().getAttribute(name);
     }

     // 设置Attribute
     public void setAttribute(String name, Object value) {
         ServletActionContext.getRequest().setAttribute(name, value);
     }

     // 获取Parameter
     public String getParameter(String name) {
         return getRequest().getParameter(name);
     }

     // 获取Parameter数组
     public String[] getParameterValues(String name) {
         return getRequest().getParameterValues(name);
     }

     // 获取Request
     public HttpServletRequest getRequest() {
         return ServletActionContext.getRequest();
     }

     // 获取Response
     public HttpServletResponse getResponse() {
         return ServletActionContext.getResponse();
     }

     // 获取Application
     public ServletContext getApplication() {
         return ServletActionContext.getServletContext();
     }

     // AJAX输出，返回null
     public String ajax(String content, String type) {
         try {
             HttpServletResponse response = ServletActionContext.getResponse();
             response.setContentType(type + ";charset=UTF-8");
             response.setHeader("Pragma", "No-cache");
             response.setHeader("Cache-Control", "no-cache");
             response.setDateHeader("Expires", 0);
             response.getWriter().write(content);
             response.getWriter().flush();
         } catch (IOException e) {
             e.printStackTrace();
         }
         return null;
     }

     // AJAX输出文本，返回null
     public String ajaxText(String text) {
         return ajax(text, "text/plain");
     }

     // AJAX输出HTML，返回null
     public String ajaxHtml(String html) {
         return ajax(html, "text/html");
     }

     // AJAX输出XML，返回null
     public String ajaxXml(String xml) {
         return ajax(xml, "text/xml");
     }

     // 根据字符串输出JSON，返回null
     public String ajaxJson(String jsonString) {
         return ajax(jsonString, "application/json");
     }

     // 根据Map输出JSON，返回null
     public String ajaxJson(Map<String, String> jsonMap) {
         return ajax(mapToJson(jsonMap), "application/json");
     }

     // 输出JSON成功消息，返回null
     public String ajaxJsonSuccessMessage(String message) {
         Map<String, String> jsonMap = new HashMap<String, String>();
         jsonMap.put("status", SUCCESS);
         jsonMap.put("message", message);
         return ajax(mapToJson(jsonMap), "application/json");
     }

     // 输出JSON错误消息，返回null
     public String ajaxJsonErrorMessage(String message) {
         Map<String, String> jsonMap = new HashMap<String, String>();
         jsonMap.put("status", ERROR);
         jsonMap.put("message", message);
         return ajax(mapToJson(jsonMap), "application/json");
     }
     // map转化为json数据
     public String mapToJson(Map<String,String> map){
         ObjectMapper mapper = new ObjectMapper();
         Writer sw = new StringWriter();
         try {
             JsonGenerator json = mapper.getJsonFactory().createJsonGenerator(sw);
             json.writeObject(map);
             sw.close();
         } catch (JsonProcessingException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }
         return sw.toString();
     }
 }

Struts2JsonPluginAction.java

 package test.action.ajax;
 import java.util.HashMap;
 import java.util.Map;
 import org.apache.struts2.json.annotations.JSON;
 import test.util.BaseAction;
 import com.opensymphony.xwork2.Action;

 public class Struts2JsonPluginAction extends BaseAction
 {
     /**
      * struts2-json-plugin 用例
      */
     private static final long serialVersionUID = -4227395311084215139L;
     // 模拟处理结果的属性
     private int[] ints = {10, 20};
     private Map<String, String> map = new HashMap<String, String>();
     private String customName = "张三";
     // 封装请求参数的三个属性
     private String field1;
     private String field2;

     // 没有setter和getter方法的字段不会被序列化
     @SuppressWarnings("unused")
     private String field3;

     // 执行
     public String struts2JsonPlugin()
     {
         map.put("name", "test");
         String test = getRequest().getParameter("field1");
         System.out.println("name:"+test);
         return Action.SUCCESS;
     }

     // 使用注释语法来改变该属性序列化后的属性名
     @JSON(name="newName")
     public Map<String, String> getMap()
     {
         return this.map;
     }
     public int[] getInts()
     {
         return this.ints;
     }
     public void setCustomName(String customName)
     {
         this.customName = customName;
     }
     public String getCustomName()
     {
         return this.customName;
     }
     public void setField1(String field1)
     {
         this.field1 = field1;
     }
     public String getField1()
     {
         return this.field1;
     }
     public void setField2(String field2)
     {
         this.field2 = field2;
     }
     public String getField2()
     {
         return this.field2;
     }
 }

• jsp

 <%@ page contentType="text/html; charset=GBK" language="java" errorPage="" %>
 <%@ taglib prefix="s" uri="/struts-tags"%>
 <%
 request.setAttribute("cxtpath",request.getContextPath());
 %>
 <!DOCTYPE html>
 <html>
 <head>
 <meta name="author" content="" />
 <meta http-equiv="Content-Type" content="text/html; charset=GBK" />
 <title>使用Struts2JsonPlugin插件 </title>
 <s:property value="cxtpath"/>
 <script src="${cxtpath}/js/common/jquery-1.9.1.js" type="text/javascript"></script>
 <script type="text/javascript">
 function struts2JsonPlugin()
 {
     // 以form1表单封装的请求参数发送请求。
     $.post('${cxtpath}/test/struts2JsonPlugin.action', $("#form1").serializeArray(),
         // data代表服务器响应，此处只是把服务器响应显示出来
         function(data) {
             console.log("data:"+JSON.stringify(data));
             for(var propName in data)
             {
                 var temp = data[propName];
                 if(propName == "newName"){
                     console.log("name:"+temp["name"])
                 }else{
                     console.log(propName + " = " + temp);
                 }
             }
         }
     );
 }
 </script>
 </head>
 <body>
 <div>使用Struts2JsonPlugin插件
 <s:form id="form1" method="post">
     field1：<s:textfield name="field1" label="field1"/><br/>
     field2：<s:textfield name="field2" label="field2"/><br/>
     field3：<s:textfield name="field3" label="field3"/><br/>
     <tr>
         <td colspan="2">
         <input type="button" value="提交" onClick="struts2JsonPlugin();"/></td>
     </tr>
 </s:form>
 </div>
 </body>
 </html>

环境：JDK1.6，MAVEN，tomcat，eclipse

源码地址：http://files.cnblogs.com/files/xiluhua/struts2-json-plugin.rar