map对象转换成json,代码编译测试 - 在线编译器(yxjc123.com)

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                    import com.fasterxml.jackson.core.JsonEncoding;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/**
 *1. map对象转换成json
 */
public class map2json {
    //JSON转java对象
    public static void main(String[] args) {
        try {
            ObjectMapper objectMapper = new ObjectMapper();
            JsonGenerator jsonGenerator = objectMapper.getJsonFactory().createJsonGenerator(System.out, JsonEncoding.UTF8);
            //map转JSON
            Map < String,Object > map = new HashMap < String,Object > ();
            map.put("one", new User("张", 12, "深圳"));
            map.put("two", new User("李", 22, "武汉"));
            map.put("three", new User("王", 32, "北京"));
            System.out.println("ObjectMapper方式");
            objectMapper.writeValue(System.out, map);  
            System.out.println("JsonGenerator方式");
            jsonGenerator.writeObject(map);
        } catch(IOException e) {
            e.printStackTrace();
        }
    }

}
//User.java
 class User {
    private String name;
    private Integer age;
    private String address;
    public User(){

    }
    public User(String name, Integer age, String address) {
        super();
        this.name = name;
        this.age = age;
        this.address = address;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
}
                

map对象转换成json在线测试，这是一个简单方便的Java在线运行工具，支持在线编译、在线调试和在线结果的实时反馈。