Question

下面这个action,为什么JSONArray jsonlist = JSONArray.fromObject( "['json','is','easy']" );会异常呢

<2012-11-8 下午11时15分02秒 GMT+08:00> <Error> <HTTP> <BEA-101020> <[ServletContext@5667705[app:_appsdir_testWebForEJB_dir module:testWebForEJB path:/testWebForEJB spec-version:2.5]] Servlet failed with Exception
java.lang.NullPointerException
at weblogic.servlet.internal.ServletResponseImpl.sendContentError(ServletResponseImpl.java:622)
at weblogic.servlet.internal.ServletResponseImpl.sendError(ServletResponseImpl.java:666)
at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:771)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:506)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
Truncated. see log file for complete stacktrace
>

代码如下：

package com.jackie.action;

import java.util.ArrayList;
import java.util.List;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

import com.jackie.entity.PMaxIdEntity;
import com.jackie.entity.userEntity;
import com.jackie.service.MaxIdService;

public class PMaxId {
MaxIdService service;
List<PMaxIdEntity> maxidList;

public String getMaxId(){
//maxidList = service.queryAll();
List<userEntity> userlist = new ArrayList<userEntity>();
userEntity user1 = new userEntity();
user1.setPassword("123123");
user1.setUsername("user1");
userEntity user2 = new userEntity();
user2.setPassword("345345");
user2.setUsername("user2");
userlist.add(user1);
userlist.add(user2);
JSONArray jsonlist = JSONArray.fromObject( "['json','is','easy']" );
System.out.println(jsonlist);
JSONObject jsondata = JSONObject.fromObject(user1);
System.out.println(jsondata);
return null;
}

public MaxIdService getService() {
return service;
}

public void setService(MaxIdService service) {
this.service = service;
}

public List<PMaxIdEntity> getMaxidList() {
return maxidList;
}

public void setMaxidList(List<PMaxIdEntity> maxidList) {
this.maxidList = maxidList;
}

}

Answer 1

最好不要直接存到JSONObject 中，struts2的VS中不支持这种方式，
如果把JSONObject的结果存这String 然后再到页面中解释，或者可以将结果封装到response中，
再从页面上取也行，也就是结果结果对象必须封装页不能直接用JSONObject对象传。

Answer 2

不是很明白，求好人帮助，在做毕业设计也遇到了同样的问题，你后来怎么解决的呢？。。急求帮助，谢谢