java 返回json数据

  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}]}

可以将存放Java对象的 列表 直接转化为 json 数组 或对象，不必要过分麻烦的转换。

从数据库取出后换：

 SourceDao sd = new SourceDao();
 JSONArray ja = new JSONArray(sd.query(content));