struts2，实现Ajax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. 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();
     }
 }

Struts2AjaxAction.java

 package test.action.ajax;
 import java.io.UnsupportedEncodingException;
 import java.util.HashMap;
 import java.util.Map;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.struts2.convention.annotation.Action;
 import org.apache.struts2.convention.annotation.Namespace;
 import org.apache.struts2.convention.annotation.ParentPackage;
 import org.apache.struts2.convention.annotation.Result;
 import test.util.BaseAction;

 @ParentPackage("ajax")
 @Namespace("/test")
 public class Struts2AjaxAction extends BaseAction
 {
     /**
      * struts2-ajax 用例
      */
     private static final long serialVersionUID = -4227395311084215139L;

     @Action(value = "gotoStruts2JsonPlugin", results = {
     @Result(name = "success", location = "/WEB-INF/content/test/ajax/struts2JsonPlugin.jsp")})
     public String gotoStruts2JsonPlugin()
     {
         return SUCCESS;
     }

     @Action(value = "gotoStruts2Ajax_post", results = {
     @Result(name = "success", location = "/WEB-INF/content/test/ajax/struts2Ajax_post.jsp")})
     public String struts2Ajax_post()
     {
         return SUCCESS;
     }

     @Action(value = "gotoStruts2Ajax_ajax", results = {
     @Result(name = "success", location = "/WEB-INF/content/test/ajax/struts2Ajax_ajax.jsp")})
     public String struts2Ajax_ajax()
     {
         return SUCCESS;
     }

     @Action(value = "post")
     public String post()
     {
         String f1 = StringUtils.defaultString(getRequest().getParameter("field1"));
         String f2 = StringUtils.defaultString(getRequest().getParameter("field2"));
         ajaxText(f1+"，测试，"+f2);
         return null;
     }

     @Action(value = "ajax")
     public String ajax() throws UnsupportedEncodingException
     {
         String f1 = StringUtils.defaultString(getRequest().getParameter("field1"));
         String f2 = StringUtils.defaultString(getRequest().getParameter("field2"));

         Map<String, String> jsonMap = new HashMap<String, String>();
         jsonMap.put(f1, f1);
         jsonMap.put(f2, f2);
         jsonMap.put("status", SUCCESS);
         super.ajaxJson(jsonMap);
         return null;
     }
 }

• jsp

struts2Ajax_post.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$.ajax提交Ajax请求</title>
<s:property value="cxtpath"/>
<script src="${cxtpath}/js/common/jquery-1.9.1.js" type="text/javascript"></script>
<script type="text/javascript">
function ajax()
{
    // 以form1表单封装的请求参数发送请求。
    var val1 = $("#form1_field1").val();
    var val2 = $("#form1_field2").val();
    $.ajax({
        url: '${cxtpath}/test/ajax.action',
        data: {"field1": val1,"field2": val2},
        dataType: "json",
        async: false,
        type: "POST",
        success: function(data) {
            console.log("data:"+JSON.stringify(data));
            if (data.status == "success") {
                console.log("succ");
            }else{
                data;
                console.log("fail");
            }
        }
    });
}
</script>
</head>
<body>
<div>使用$.ajax提交Ajax请求
<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="ajax();"/></td>
    </tr>
</s:form>
</div>
</body>
</html>

struts2Ajax_ajax.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$.post提交Ajax请求</title>
 <s:property value="cxtpath"/>
 <script src="${cxtpath}/js/common/jquery-1.9.1.js" type="text/javascript"></script>
 <script type="text/javascript">
 function post()
 {
     // 以form1表单封装的请求参数发送请求。
     $.post('${cxtpath}/test/post.action', $("#form1").serializeArray(),
         // data代表服务器响应，此处只是把服务器响应显示出来
         function(data) {
             console.log("data:"+JSON.stringify(data));
         }
     )
 }
 </script>
 </head>
 <body>
 <div>使用$.post提交Ajax请求
 <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="post();"/></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-Ajax.rar