（二）fastJson和其他类型转换

//String to Json 
        String str = "{\"语文\":\"88\",\"数学\":\"78\",\"计算机\":\"99\"}";
        JSONObject jsonObject;
        jsonObject = JSONObject.parseObject(str); 
        System.out.println("jsonObject: "+jsonObject);
        // Json to String 
        String chinessName = jsonObject.getString("语文");
        System.out.println("chinessName: "+chinessName);
        

        //对象转json字符串简单，就一个toJSONString(对象);方法
        User user = new User();
        user.setName("zhangsan");
        user.setPassword("123");
        user.setAge(18);
        String string = JSON.toJSONString(user);
        System.out.println("user.toString(): "+user.toString());
        System.out.println("JSON.toJSONString(user): "+string);
        
        System.out.println("..................................................");
        
        //List的json字符串转会list对象，只需要使用parseArray(str,类名.class);
        User user1 = new User();
        user1.setName("lisi");
        user1.setPassword("321");
        user1.setAge(17);
        List users = new ArrayList();
        users.add(user);
        users.add(user1);
        String string2 = JSON.toJSONString(users);
        System.out.println("user list"+string2);
        
        List list = JSON.parseArray(string2, User.class);
        for (User user2 : list) {
            System.out.println(user2);
        }
        
        System.out.println("..................................................");
        
        //Map的json字符串转为map对象，使用parseObject(str,new TypeReference
        Map map = new HashMap();
        map.put("用户1", user);
        map.put("用户2", user1);
        String string3 = JSON.toJSONString(map);
        System.out.println(string3);