1. 简单的直接Bean.class
2. 复杂的用 TypeReference
public class TestMain2 {
代码如下：
public static void main(String[] args) throws JsonProcessingException {
/*
首先说明 readValue 针对String 一共有3个重载，如下：
public
public
public
*/
ObjectMapper objectMapper = new ObjectMapper();
String json1 = "{"userName":"小李飞刀","age":18,"addTime":1591851786568}";
String json2 = "[{"userName":"小李飞刀","age":18,"addTime":123}, {"userName":"小李飞刀2","age":182,"addTime":1234}]";
//1.最简单的常用方法，直接将一个json转换成实体类
UserBase userBase1 = objectMapper.readValue(json1, UserBase.class); //简单类型的时候，这样最方便
System.out.println("简单: " + userBase1.getUserName());
//用 TypeReference 也可以，但是麻烦 不如第一种直接 TypeReference 主要针对繁杂类型
//UserBase userBase2 = objectMapper.readValue(json1, new TypeReference
//2.把Json转换成map，必须使用 TypeReference , map的类型定义 可以根据实际情况来定，比如若值都是String那么就可以 Map
Map
System.out.println("map: " + userBaseMap.get("userName"));
//3.list
List
System.out.println("list: " + userBaseList.get(0).getUserName());
//4.Bean[] 数组，必须用 TypeReference
UserBase[] userBaseAry = objectMapper.readValue(json2, new TypeReference
System.out.println("ary: " + userBaseAry[0].getUserName());
}
}
