1. pom依赖

 <dependency>
	<groupId>com.google.code.gson</groupId>
	<artifactId>gson</artifactId>
	<version>2.8.8</version>
</dependency>

2. javaBean转json字符串

import com.google.gson.Gson;

public class Example {
    public static void main(String[] args) {
        Person person = new Person();
        person.setName("John");
        person.setAge(30);
        person.setAddress("New York");

        Gson gson = new Gson();
        String json = gson.toJson(person);
        System.out.println(json);
    }
}

class Person {
    private String name;
    private int age;
    private String address;

    // getters and setters
}

输出结果：

{"name":"John","age":30,"address":"New York"}