Java中Map与对象之间互相转换的几种常用方式

	public static Map<String,Object> initMap(){
        Map<String,Object> map = new HashMap<>();
        map.put("userId", 1L);
        map.put("userName", "张三");
        map.put("age", 18);
        map.put("weight", 58.6);
        return map;
    }
    
	public void mapToObj1(){
        Map<String,Object> map = initMap();
        User user = new User();
        BeanMap beanMap = BeanMap.create(user);
        beanMap.putAll(map);
        System.out.println(user);
    }

	public void mapToObj2(){
        Map<String,Object> map = initMap();
        String s = JSON.toJSONString(map);
        User user = JSON.parseObject(s, User.class);
        System.out.println(user);
    }

	public void mapToObj3(){
        Map<String,Object> map = initMap();
        Gson gson = new Gson();
        String s = gson.toJson(map);
        User user = gson.fromJson(s, User.class);
        System.out.println(user);
    }

	public static User initUser(){
        User user = new User();
        user.setUserId(2L);
        user.setUserName("李四");
        user.setAge(19);
        user.setWeight(60.4);
        return user;
    }
    
	public void objToMap1(){
        User user = initUser();
        BeanMap beanMap = BeanMap.create(user);
        Map<String, Object> map = beanMap;
        System.out.println(map);
    }

	public void objToMap2(){
        User user = initUser();
        String s = JSON.toJSONString(user);
        Map<String, Object> map = JSON.parseObject(s, new TypeReference<Map<String,Object>>(){});
        //下面这种方式也可以转
        //Map<String, Object> map = JSON.parseObject(s, HashMap.class);
        System.out.println(map);
    }

	public void objToMap3(){
        User user = initUser();
        Gson gson = new Gson();
        String s = gson.toJson(user);
        Map<String, Object> map = gson.fromJson(s, HashMap.class);
        System.out.println(map);
    }