1. 簡單的直接Bean.class
2. 複雜的用 TypeReference
public class TestMain2 {
代碼如下:
public static void main(String[] args) throws JsonProcessingException {
/*
首先說明 readValue 針對String 一共有3個重載,如下:
public
public
public
*/
ObjectMapper objectMapper = new ObjectMapper();
String json1 = "{"userName":"小李飛刀","age":18,"addTime":1591851786568}";
String json2 = "[{"userName":"小李飛刀","age":18,"addTime":123}, {"userName":"小李飛刀2","age":182,"addTime":1234}]";
//1.最簡單的常用方法,直接將一個json轉換成實體類
UserBase userBase1 = objectMapper.readValue(json1, UserBase.class); //簡單類型的時候,這樣最方便
System.out.println("簡單: " + userBase1.getUserName());
//用 TypeReference 也可以,但是麻煩 不如第一種直接 TypeReference 主要針對繁雜類型
//UserBase userBase2 = objectMapper.readValue(json1, new TypeReference
//2.把Json轉換成map,必須使用 TypeReference , map的類型定義 可以根據實際情況來定,比如若值都是String那麼就可以 Map
Map
System.out.println("map: " + userBaseMap.get("userName"));
//3.list
List
System.out.println("list: " + userBaseList.get(0).getUserName());
//4.Bean[] 數組,必須用 TypeReference
UserBase[] userBaseAry = objectMapper.readValue(json2, new TypeReference
System.out.println("ary: " + userBaseAry[0].getUserName());
}
}