Json使用示例

Posted 2020-10-10 王晓东

使用Json，可以下载如下所示的6个Jar包

 

整个工程目录结构如下：

 

简单的用法：

package json;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

public class JsonTest {

    public static void main(String[] args) {
        //1、输出Json字符串
        JSONObject container1 = new JSONObject();
        container1.put("ClassName", "1班");
        System.out.println(container1.toString());
        
        //2、输出Json字符串 + Json数组
        JSONArray className =new JSONArray();
        className.add("2班");
        className.add("3班");
        container1.put("classname", className);
        System.out.println(container1.toString());
    
        //3、输出Json字符串 + Json数组 + Json字符串
        JSONObject classInfo = new JSONObject();
        classInfo.put("stuCount", 50);
        classInfo.put("leader", "rah");
        container1.put("classInfo", classInfo);
        System.out.println(container1);
        
        //4、字符串 转为 Json数组对象
        String jsonMessage = 
                "[{\'num\':\'成绩\', \'外语\':88, \'历史\':65, \'地理\':99, \'object\':{\'aaa\':\'1111\',\'bbb\':\'2222\',\'cccc\':\'3333\'}}," +
                   "{\'num\':\'兴趣\', \'外语\':28, \'历史\':45, \'地理\':19, \'object\':{\'aaa\':\'11a11\',\'bbb\':\'2222\',\'cccc\':\'3333\'}}," +
                   "{\'num\':\'爱好\', \'外语\':48, \'历史\':62, \'地理\':39, \'object\':{\'aaa\':\'11c11\',\'bbb\':\'2222\',\'cccc\':\'3333\'}}]";
        
        JSONArray test = JSONArray.fromObject(jsonMessage);
        System.out.println(test.toString());
        //获取Json数组的某个索引的值
        System.out.println(test.get(0));
        System.out.println(test.get(1));
    }
    
}