后台json传递
json除了可以用于前台传递，还可用于后台之间传递。它可以传递List,Map,Bean等类型的数据。例如：
User u1=new User();u1.setUsername("zy");u1.setPassword("123");User u2=new User();u2.setUsername("msl");u2.setPassword("456"); List list = new ArrayList();//把两个对象放进list中list.add(u1); list.add(u2); JSONArray jsonArray = JSONArray.fromObject( list ); //把list放进json数组 Map map = new HashMap(); map.put("message", "111"); map.put("users", jsonArray); //把json数组做为一个值放进Map中JSONObject jsonObject = JSONObject.fromObject(map); //把map放进json对象中PrintWriter out = response.getWriter();out.print(jsonObject);// 传递json
传递的json格式为： {"message":"111","users":[{"password":"123","username":"zy"},{"password":"456","username":"msl"}]}
在接收端的java文件中取：
returnJson是从输入流中得到的json格式的字符串。输出为：
{"message":"111","users":[{"password":"123","username":"zy"}, {"password":"456","username":"msl"}]}
if(returnJson != null && returnJson != ""){ String strJson = returnJson.replace("?(", "").replace(")", "").replace(";", ""); if(strJson.startsWith("{")){ JSONObject jsonObject = JSONObject.fromObject(strJson); JSONArray jsonArray = JSONArray.fromObject(jsonObject.get("users")); for (int i = 0, len = jsonArray.size(); i < len; i++) { JSONObject jsonUser = jsonArray.getJSONObject(i);User vo = (User)JSONObject.toBean(jsonUser, User.class);System.out.println(vo.getUsername()+":"+vo.getPassword()); } } }
ps: 在这里通过toBean的方法把json对象转换成了java对象。
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