map，对象，字符串转为json格式

最新推荐文章于 2023-03-20 09:33:07 发布

原创最新推荐文章于 2023-03-20 09:33:07 发布 · 1.1k 阅读

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本文介绍了如何将Map、对象以及字符串转换为JSON格式。首先展示了一个Map实例并利用JSONObject将其转换为JSON对象，然后展示了直接将对象转换为JSON的方法，最后解释了如何将包含键值对的字符串转换为JSON，注意字符串中的转义字符。

一

将map转为json

新建一个map

Map<String, String> map = new HashMap<String, String>();
map.put("1","1");
map.put("2","2");

使用JSONObject就可以将map直接转为json

package test;

import java.io.File;
import java.util.HashMap;
import java.util.Map;
import org.json.JSONObject;

public class Test {
	public static void main(String[] args) {
		demo1();
	}
	public static void demo1() {
		//map->json
		Map<String, String> map = new HashMap<String, String>();
		map.put("1","1");
		map.put("2","2");
		JSONObject json = new JSONObject(map);
		System.out.println(json);
		//{"1":"1","2":"2"}
		//json格式
	} 
}

输出结果为{"1":"1","2":"2"}

二

将对象转为json

直接使用JSONObject 来将对象转为json格式：JSONObject json = new JSONObject(entity);

新建一个对象

package dao;

public class Entity {
	String name;
	int age;
	Address address;
	public Entity() {
	}
	public Entity(String name, int age, Address address) {
		super();
		this.name = name;
		this.age = age;
		this.address = address;
	}
	public Address getAddress() {
		return address;
	}
	public void setAddress(Address address) {
		this.address = address;
	}
	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;
	}

	@Override
	public String toString() {
		// TODO Auto-generated method stub
		return "name" + " " + name + " " + "age";
	}

}

package dao;

public class Address {
	String a1;
	String a2;

	public Address() {
	}

	public Address(String a1, String a2) {
		super();
		this.a1 = a1;
		this.a2 = a2;
	}

	public String getA1() {
		return a1;
	}

	public void setA1(String a1) {
		this.a1 = a1;
	}

	public String getA2() {
		return a2;
	}

	public void setA2(String a2) {
		this.a2 = a2;
	}

}

package test;

import org.json.JSONObject;
import dao.Address;
import dao.Entity;

public class Test {
	public static void main(String[] args) throws IOException {
		demo2();
	}
	public static void demo2() {
		//javaBean->json
		Entity entity = new Entity();
		Address address = new Address("a1","a2"); 
		entity.setAddress(address);
		entity.setAge(15);
		entity.setName("s");
		JSONObject json = new  JSONObject(entity); 
		System.out.println(json);
		//{"address":{"a1":"a1","a2":"a2"},"name":"s","age":15}
	}
	
}

三

将字符串转为json

在字符串中要写成键值对的形式，如果是字符串要有转义字符

String str = "{\"name\":\"zs\",\"age\":23}";

package test;

import org.json.JSONObject;

public class Test {
	public static void main(String[] args){
		demo3();
	}
	public static void demo3() {
		String  str = "{\"name\":\"zs\",\"age\":23}"; 
		JSONObject json = new JSONObject(str);
		System.out.println(str);
		//{"name":"zs","age":23}
	}
}