Question

怎么判断返回值的格式为json

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Answer 1

例如：　
　　Student st1 = new Student(1, "dg", 18, new Date());
　　Student st2 = new Student(2, "dg", 18, new Date());
　　Student st3 = new Student(3, "dg", 18, new Date());
　　Student st4 = new Student(4, "dg", 18, new Date());
　　Student st5 = new Student(5, "dg", 18, new Date());
　　List li = new ArrayList();
　　JSONObject JO1 = new JSONObject(st1);
　　JSONObject JO2 = new JSONObject(st2);
　　JSONObject JO3 = new JSONObject(st3);
　　JSONObject JO4 = new JSONObject(st4);
　　JSONObject JO5 = new JSONObject(st5);
　　li.add(JO1);
　　li.add(JO2);
　　li.add(JO3);
　　li.add(JO4);
　　li.add(JO5);
　　JSONArray Ja = new JSONArray(li);
　　Map ma = new HashMap();
　　ma.put("Result", "OK");
　　ma.put("Records", Ja);
　　JSONObject js = new JSONObject(ma);
　　out.print(js);

　　返回结果：

　　{"Result":"OK","Records":[{"recordDate":"Fri Dec 16 17:54:39 CST 2011","name":"dg","age":18,"personId":1},{"recordDate":"Fri Dec 16 17:54:39 CST 2011","name":"dg","age":18,"personId":2},{"recordDate":"Fri Dec 16 17:54:39 CST 2011","name":"dg","age":18,"personId":3},{"recordDate":"Fri Dec 16 17:54:39 CST 2011","name":"dg","age":18,"personId":4},{"recordDate":"Fri Dec 16 17:54:39 CST 2011","name":"dg","age":18,"personId":5}]}