Map<String,String>转换json字符串

import java.util.HashMap;
import java.util.Map;
import net.sf.json.JSONObject;

public class testJson {
 
    public static void main(String[] args) {
        testPingping();
    }
    public static void testPingping(){ 
        Map<String, String> smallMap = new HashMap<String, String>(); 
        smallMap.put("userId", "438");
        smallMap.put("name", "平平/萍萍");
        smallMap.put("sex", "不知男女");
        smallMap.put("reason", "和学成睡一晚，后来学成嘴疼"); 
    JSONObject jsonObject = JSONObject.fromObject(smallMap);
    System.out.println("下面是专家开具的鉴定结果："); //A joke
    System.out.println(jsonObject);
    System.out.println("患者鉴定完毕！"); //A joke
    System.out.println("下一位"); //A joke

    } 
}