18 gson fastjson

1 gson

1.1依存関係を追加する

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

1.2一般的に使用される方法：

文字列へのオブジェクト：

User userObject = new User(  
    "Norman", 
    "[email protected]", 
    26, 
    true
);

Gson gson = new Gson();
String userJson = gson.toJson(userObject);

オブジェクトへの文字列：

String userJson = "{'isDeveloper':false,'name':'xiaoqiang','age':26,'email':'[email protected]'}";

User user = gson.fromJson(userJson, User.class);

https://blog.csdn.net/chenrenxiang/article/details/80291224を参照して
ください

2 fastjson

package demo;
import java.util.ArrayList;
import java.util.List;
import org.junit.Test;
import com.alibaba.fastjson.JSON;

/**
 * fastJson测试类
 * @author dmego
 *
 */
public class TestFastJosn {
    
    
	/**
	 * java对象转 json字符串 
	 */
	@Test
	public void objectTOJson(){
    
    
		//简单java类转json字符串
		User user = new User("dmego", "123456");
		String UserJson = JSON.toJSONString(user);
		System.out.println("简单java类转json字符串:"+UserJson);
		
		//List<Object>转json字符串
		User user1 = new User("zhangsan", "123123");
		User user2 = new User("lisi", "321321");
		List<User> users = new ArrayList<User>();
		users.add(user1);
		users.add(user2);
		String ListUserJson = JSON.toJSONString(users);
		System.out.println("List<Object>转json字符串:"+ListUserJson);	
		
		//复杂java类转json字符串
		UserGroup userGroup = new UserGroup("userGroup", users);
		String userGroupJson = JSON.toJSONString(userGroup);
		System.out.println("复杂java类转json字符串:"+userGroupJson);		
		
	}
	
	/**
	 * json字符串转java对象
	 * 注：字符串中使用双引号需要转义 (" --> \"),这里使用的是单引号
	 */
	@Test
	public void JsonTOObject(){
    
    
		/* json字符串转简单java对象
	     * 字符串：{"password":"123456","username":"dmego"}*/
		
		String jsonStr1 = "{'password':'123456','username':'dmego'}";
		User user = JSON.parseObject(jsonStr1, User.class);
		System.out.println("json字符串转简单java对象:"+user.toString());
		
		/*
		 * json字符串转List<Object>对象
		 * 字符串：[{"password":"123123","username":"zhangsan"},{"password":"321321","username":"lisi"}]
		 */
		String jsonStr2 = "[{'password':'123123','username':'zhangsan'},{'password':'321321','username':'lisi'}]";
		List<User> users = JSON.parseArray(jsonStr2, User.class);
		System.out.println("json字符串转List<Object>对象:"+users.toString());
			
		/*json字符串转复杂java对象
		 * 字符串：{"name":"userGroup","users":[{"password":"123123","username":"zhangsan"},{"password":"321321","username":"lisi"}]}
		 * */
		String jsonStr3 = "{'name':'userGroup','users':[{'password':'123123','username':'zhangsan'},{'password':'321321','username':'lisi'}]}";
		UserGroup userGroup = JSON.parseObject(jsonStr3, UserGroup.class);
		System.out.println("json字符串转复杂java对象:"+userGroup);	
	}
}

参照：https：
//www.cnblogs.com/dmego/p/9033080.html