自己写的一个给struts返回的json数据包装格式类，不喜勿喷，原创，需在项目中引入com.alibaba.fastjson的jar包
先看下效果（这里没有使用msg，有兴趣的往下看）：
上demo：
1 import java.util.HashMap; 2 ?3 ?4 /** 5 * JSON响应处理工具类 6 * ?7 * 返回一个json对象，包含status/msg/data， 8 * checkOK()默认status:200/checkFail()默认status:500 9 * 其中checkOK(Object data)比较特殊，直接返回的是这个对象的json10 * 其他均为status/msg/data返回格式11 * 12 * @author Hellxz13 * @date 2017年10月21日14 * @version 1.015 */16 public class JsonResult {17 18 ????/**检查成功，返回200**/19 ????public static Object checkOK(){20 ????????Object result = build(200, null, null);21 ????????return result;22 ????}23 ????/**检测成功，返回200,msg**/24 ????public static Object checkOK(String msg){25 ????????Object result = build(200, msg, null);26 ????????return result;27 ????}28 ????/**检查成功，直接返回json对象**/29 ????public static Object checkOK(Object data){30 ????????Object result = com.alibaba.fastjson.JSONObject.toJSON(data);31 ????????return result;32 ????}33 ????34 ????/**检查成功的响应，返回200,msg,data**/35 ????public static Object checkOK(String msg, Object data){36 ????????Object result = build(200, msg, data);37 ????????return result;38 ????}39 ????40 ????/**检查失败，只返回500**/41 ????public static Object checkFail(){42 ????????Object result = build(500, null, null);43 ????????return result;44 ????}45 ????public static Object checkFail(String msg){46 ????????Object result = build(500, msg, null);47 ????????return result;48 ????}49 ????50 ????/**检查失败的响应 500,msg,data**/51 ????public static Object checkFail(String msg,Object data){52 ????????Object result = build(500, msg, data);53 ????????return result;54 ????}55 ????56 ????/**返回转换后的json对象（自定义状态码，信息，data）**/57 ????public static Object build(Integer status, String msg, Object data){58 ????????HashMap<String,Object> map = new HashMap<>();59 ????????map.put("status", status);60 ????????map.put("msg", msg);61 ????????map.put("data", data);62 ????????Object json = com.alibaba.fastjson.JSONObject.toJSON(map);63 ????????return json;64 ????}65 ????66 }因为这是个工具类，所有方法都是静态方法，所以，写出输出流需要自己手动写出来，下边就简单写一个需要放在action类中的小方法，配合以上工具类食用风味更佳~！
/**以response形式将对象写回客户端，推荐传入JSON对象**/ ???public void writeOut(Object obj){ ???????response.setContentType("text/json;charset=utf-8"); ???????PrintWriter writer = null; ???????try { ???????????writer = response.getWriter(); ???????????writer.println(obj); ???????} catch (IOException e) { ???????????e.printStackTrace(); ???????} finally{ ???????????writer.flush(); ???????????writer.close(); ???????} ???}于是在action中只需要引入最上边提到的工具类，然后用这个方法写回给客户端就好了，so简单~
//写出成功writeOut(JsonResult.checkOK();writeOut(JsonResult.checkOK("输出成功");writeOut(JsonResult.checkOK("输出成功"，Object o);writeOut(JsonResult.checkOK(Object o); //这个是唯一不同格式的//写出失败writeOut(JsonResult.checkFail();writeOut(JsonResult.checkFail("输出失败");writeOut(JsonResult.checkFail("输出失败"，Object o);//自定义writeOut(JsonResult.build(400,"你好",Object o);如果有更好的代码欢迎交流
【自制工具类】struts返回json数据包装格式类
原文地址：http://www.cnblogs.com/hellxz/p/7782264.html