json java simple-json

public class QueryAttribute implements JSONStreamAware {

   private String query;
   private String cat;
   private int guanwang;
   private String icon;
   private String entity_name;
   private double score;
   private String clkurl;

   public QueryAttribute(String query, double score, String cat,
        String entity_name, int guanwang, String icon, String clkurl) {
     this.query = query;
     this.cat = cat;
     this.entity_name = entity_name;
     this.score = score;
     this.guanwang = guanwang;
     this.icon = icon;
     this.clkurl = clkurl;
   }

   public void writeJSONString(Writer out) throws IOException {
     LinkedHashMap obj = new LinkedHashMap();
     obj.put("query", query);
     obj.put("score", score);
     obj.put("cat", cat);
     obj.put("ename", entity_name);
     obj.put("gw", guanwang);
     obj.put("icon", icon);
     obj.put("clkurl", clkurl);
     JSONValue.writeJSONString(obj, out);
   }
}

import org.json.simple.JSONObject;
import org.json.simple.JSONArray;
import org.json.simple.JSONValue;
import java.util.*;
public class Segment
{
    public static void main(String[] args)
    {
        String s="[0,{\"1\":{\"2\":{\"3\":{\"4\":[5,{\"6\":7}]}}}}]";
        Object obj = JSONValue.parse(s);
        JSONArray array = (JSONArray)obj;
        System.out.println(array.get(0));
        System.out.println(array.get(1));
        System.out.println();
        JSONObject obj2 = (JSONObject)array.get(1);
        System.out.println("=============field \"1\"=======");
        System.out.println(obj2.get("1"));
        System.out.println(obj);

        s = "{}";
        obj = JSONValue.parse(s);
        System.out.println(obj);

        s = "[5,]";
        obj = JSONValue.parse(s);
        System.out.println(obj);

        s = "[5,,2]";
        obj = JSONValue.parse(s);
        System.out.println(obj);
    }
}