JSON解析依赖包

JSON

JSON (JavaScript Object Notation) 是一种轻量级的数据交换格式，易于人阅读和编写，同时也易于机器解析和生成。它基于 JavaScript 的一个子集，但独立于编程语言，广泛用于 Web 应用和 API 数据传输。

User对象

@Data
@NoArgsConstructor
public class User 
{
	private String name;
	private Integer age;
}

fastjson

依赖

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>2.0.31</version>
</dependency>

快速使用

/**
	 * fastjson依赖
	 */
	
	//对象
	@Test
	public void fastjsonJavaBean()
	{
		String jsonUser = JSON.toJSONString(new User("张三", 18));//User对象转换JSON
		System.out.println("Json: "+jsonUser);
		
		User user = JSON.parseObject(jsonUser,User.class);//JSON转换User对象
		System.out.println("Object: "+user);
		
		//结果：
		//Json: {"age":18,"name":"张三"}
		//Object: User(name=张三, age=18)
	}
	
	//集合
	@Test
	public void fastjsonList()
	{
		String jsonList = JSON.toJSONString(Arrays.asList("张三", "李四"));//集合转换JSON
		System.out.println("Json: "+jsonList);
		
		List list = JSON.parseObject(jsonList,ArrayList.class);//JSON转换集合
		System.out.println("List: "+list);

		//结果：
		//Json: ["张三","李四"]
		//List: [张三, 李四]
	}
	
	//Map
	@Test
	public void fastjsonHashMap()
	{
		Map map = new HashMap();
		map.put("user1",new User("张三",50));
		map.put("user2",new User("李四",25));
		String jsonHashMap = JSON.toJSONString(map);//Map对象转换JSON
		System.out.println("Json: "+jsonHashMap);
		
		HashMap hashMap = JSON.parseObject(jsonHashMap, HashMap.class);//JSON转换Map对象
		System.out.println("Map: "+hashMap);

		//结果：
		//Json: {"user1":{"age":50,"name":"张三"},"user2":{"age":25,"name":"李四"}}
		//Map: {user1={"name":"张三","age":50}, user2={"name":"李四","age":25}}
	}

gson

依赖

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

快速使用

	/**
	 * gson
	 */
	
	//对象
	@Test
	public void gsonJavaBean()
	{
		Gson gson = new Gson();
		
		String jsonUser = gson.toJson(new User("张三", 18));//User对象转换JSON
		System.out.println("Json: "+jsonUser);

		User user = gson.fromJson(jsonUser, User.class);//JSON转换User对象
		System.out.println("Object: "+user);
		
		//结果：
		//Json: {"name":"张三","age":18}
		//Object: User(name=张三, age=18)
	}
	
	//集合
	@Test
	public void gsonList()
	{
		Gson gson = new Gson();
		String jsonList = gson.toJson(Arrays.asList("张三", "李四"));//集合转换JSON
		System.out.println("Json: "+jsonList);

		List list = gson.fromJson(jsonList, ArrayList.class);//JSON转换集合
		System.out.println("List: "+list);

		//结果：
		//Json: ["张三","李四"]
		//List: [张三, 李四]
	}
	
	//HashMap
	@Test
	public void gsonHashMap()
	{
		Gson gson = new Gson();

		Map map = new HashMap();
		map.put("user1",new User("张三",50));
		map.put("user2",new User("李四",25));
		String jsonHashMap = gson.toJson(map);//Map对象转换JSON
		System.out.println("Json: "+jsonHashMap);

		HashMap hashMap = gson.fromJson(jsonHashMap, HashMap.class);//JSON转换Map对象
		System.out.println("Map: "+hashMap);

		//结果：
		//Json: {"user1":{"name":"张三","age":50},"user2":{"name":"李四","age":25}}
		//Map: {user1={name=张三, age=50.0}, user2={name=李四, age=25.0}}
	}