struts2 json传递对象

今天在用struts2 异步请求从后台传一个对象到前台时遇到了一个小小的问题，现在此作一个标记，把主要的代码贴上以作备忘。

struts.xml

[html] view plaincopy

1. <action name="getSystemContactorInfo" class="userAction" method="getSystemContactorInfo">  
2.             <result type="json">  
3.                 <param name="includeProperties">systemContactor\.userName,systemContactor\.cellPhone,  
4.                     systemContactor\.notesMail  
5.                 </param>  
6.                 <!-- <param name="includeProperties">systemContactor</param> 这样不对-->  
7.                 <!-- <param name="includeProperties">systemContactor.*</param> 这样同样不正确-->  
8.             </result>  
9.         </action>  

UserAction

[java] view plaincopy

1. public String getSystemContactorInfo() {  
2.         UserModel systemContactor = new UserModel();  
3.         systemContactor.setUserName("张三");  
4.         systemContactor.setCellPhone("13240151465");  
5.         systemContactor.setNotesMail("[e-mail]");  
6.         return Action.SUCCESS;  
7.      }  

UserModel

[java] view plaincopy

1. public class UserModel{  
2.    private String userName;  
3.    private String cellPhone;  
4.    private String notesMail;  
5. //省略get、set方法  
6. }  

jsp页面中

[html] view plaincopy

1. $.ajax({  
2.             type:'post',  
3.             url: 'getSystemContactorInfo.action',  
4.             dataType: 'json',  
5.             async: true,  
6.             success: function showContent(json) {  
7.                 var userInfo = json.systemContactor;  
8.                 $("#userName").html(userInfo.userName);  
9.                 $("#cellPhone").html(userInfo.cellPhone);  
10.                 $("#notesMail").html(userInfo.notesMail);  
11.             }  
12.         });  

<param name="includeProperties">systemContactor</param> 当systemContactor为一个字串或数字时可以这样写
<param name="includeProperties">systemContactor.*</param>当systemContactor为list时可这样传
到现在也不是太明白当systemContactor为一个对象时为什么不能直接写在里面