jquery发送ajax请求，以及struts2的action响应请求并传回json数据的做法

-------------------jquery代码------------------

package com.login.action;

import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.login.pojo.Customer;
import com.login.service.LoginService;
import com.opensymphony.xwork2.ActionSupport;
import com.util.classes.JSONBean;

public class loginAction extends ActionSupport {

   // 客户管理服务
   private LoginService loginService;

   public static final String TILES = "tiles";
   protected String targetUrl; // 跳转的页面

   // 用户名
   private String username;
   // 密码，旧密码
   private String password;
   // 验证码
   private String checkCode;
   // 记住用户名
   private String remember;

   private JSONBean root = new JSONBean(); //定义要回传的json对象，注意一定要有get，set方法

   public JSONBean getRoot() {
       return root;
   }
   public void setRoot(JSONBean root) {
       this.root = root;
   }

   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 getCheckCode() {
       return checkCode;
   }

   public void setCheckCode(String checkCode) {
       this.checkCode = checkCode;
   }

   public String getRemember() {
       return remember;
   }

   public void setRemember(String remember) {
       this.remember = remember;
   }

   public String validateUser(){
       HttpSession session = ServletActionContext.getRequest().getSession();
       String v_code = session.getAttribute("vcode").toString();
       String msg ="";
       Customer dbCustomer = null;
       if(!checkCode.equals(v_code)){
           msg="验证码错误";
           root.setSuccess(false);
           root.setMsg(msg);
       }else{
           msg="登录成功";
           dbCustomer=loginService.checkCustomerByLoginId(username);

           if(dbCustomer!=null){
               root.setSuccess(true);
               root.setMsg(msg);
           }else{
               dbCustomer = loginService.checkCustomerByUsername(username);
               msg="登录成功";
               if(dbCustomer!=null){
                   root.setSuccess(true);
                   root.setMsg(msg);
               }else{
                   root.setMsg("用户在系统中不存在！");
               }
           }

       }
       return "json";
   }
}
jsonBean 类中定义了一些变量如success,msg，jsonMap 也可以直接在action中定义

------------------------------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="default" extends="struts-default,tiles-default,json-default"> 
                <action name="*" class="loginAction" method="{1}">
                     <result name="success">page/jsp/login.jsp</result>
                     <result name="tiles" type="tiles" >${targetUrl}</result>
                     <result name="json" type="json">　　　　
                          <param name="root">root</param>
                      </result>
                </action>
        </package>
    </struts>

--------------------------------对了最后记得项目中一定要有json的jar struts2-json-plugin-2.3.4.jar 版本尽量跟struts2的核心包的版本一致---------------------