json和对象之间的转换

@Test
    public void parseJsonStrToJsonObj() {
        //json字符
        String jsonStr = "{\"id\":\"1\",\"email\":\"12312@qq.com\",\"username\":\"qwerty\",\"bronDate\":\"2012-12-12\",\"num\":\"32.2\",\"password\":\"342frsd\"}";
        //转json对象
        JSONObject jsonUser = JSONObject.fromObject(jsonStr);
        System.out.println(jsonUser.get("id"));
        System.out.println(jsonUser.get("username"));
        System.out.println(jsonUser.get("bronDate"));
        System.out.println(jsonUser.get("num"));
        //json对象转json字符串
        System.out.println(jsonUser.toString());
        //转java对象
        User user = (User)JSONObject.toBean(jsonUser, User.class);
        System.out.println(user);
    }
    
    //java.list对象转json数组对象
    @Test
    public void parseJavaListToJsonStrArray(){
        
        //java.list对象
        List<User> userList = new ArrayList<User>();
        for (int i = 0; i < 6; i++) {
            User user = new User();
            user.setId(i);
            user.setBronDate(new Date());
            user.setEmail("4237498@qq.com");
            user.setUsername("xp"+i);
            userList.add(user);
        }
        //转json数组对象
        JSONArray jsonUserAray = JSONArray.fromObject(userList);
        System.out.println(jsonUserAray);
        //json字符串
        System.out.println(jsonUserAray.toString());
        System.out.println("=======================");
        
        //json数组转java.list
        @SuppressWarnings("unchecked")
        List<User> list = (List<User>)JSONArray.toCollection(jsonUserAray, User.class);
        System.out.println(list);
    }