java将map转json字符串或者再将json字符串转回map，java将对象转json字符串或者互想转换，对象集合和json字符串互转

1.导入hutool工具依赖

  <dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId><version>5.8.16</version></dependency>

2.直接复制一下代码运行

import cn.hutool.json.JSONUtil;import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;public class Test {public static void main(String[] args) throws Exception{Map<String,String> map = new HashMap<>();map.put("host","127.0.0.1");map.put("port","1433");map.put("username","xu");map.put("password","123456");//将map转json字符串String jsonStr = JSONUtil.toJsonStr(map);System.out.println("jsonStr:"+jsonStr);//将json字符串转mapMap<String,String> jsonStrTomap = JSONUtil.toBean(jsonStr, Map.class);System.out.println("jsonStrTomap:"+jsonStrTomap);Person person = new Person();person.setAge(18);person.setName("妹妹今年18岁");//将person对象转json字符串String personJSonStr = JSONUtil.toJsonStr(person);System.out.println("personJSonStr:"+personJSonStr);//将person字符串转换回person对象Person personFromJsonStr = JSONUtil.toBean(personJSonStr, Person.class);System.out.println("personFromJsonStr:"+personFromJsonStr);//person对象集合转json字符串List<Person> personList = new ArrayList<>();for (int i = 0; i < 10; i++) {Person p = new Person();p.setAge(18+i);p.setName("妹妹今年"+p.getAge()+"岁");personList.add(p);}//将集合对象转json字符串String personListJsonStr = JSONUtil.toJsonStr(personList);System.out.println("personListJsonStr:"+personListJsonStr);//再将json字符串转回到对象集合List<Person> personListFromJsonStr = JSONUtil.toList(personListJsonStr, Person.class);System.out.println("personListFromJsonStr:"+personListFromJsonStr);}static class Person {public String name;public int age;public Person() {}public Person(String name, int age) {this.name = name;this.age = age;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}@Overridepublic String toString() {return "Person{" +"name='" + name + '\'' +", age=" + age +'}';}}}