JSONObject与JSONArray的使用1

一、JAR包简介

要使程序可以运行必须引入JSON-lib包,JSON-lib包同时依赖于以下的JAR包:

1.commons-lang.jar

2.commons-beanutils.jar

3.commons-collections.jar

4.commons-logging.jar

5.ezmorph.jar

6.json-lib-2.2.2-jdk15.jar

二、JSONObject(json对象),JSONArray(json数组)的创建

import java.util.ArrayList;
import java.util.HashMap;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

public class Test {

    public static void main(String[] args) {
        //JsonObject和JsonArray区别就是JsonObject是对象形式,JsonArray是数组形式
        //创建JsonObject第一种方法
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("UserName", "xxb");
        jsonObject.put("age", "27");
        System.out.println("jsonObject1:" + jsonObject);
        
        //创建JsonObject第二种方法
        HashMap<String, String> hashMap = new HashMap<String, String>();
        hashMap.put("UserName", "xxb");
        hashMap.put("age", "27");
        System.out.println("jsonObject2:" + JSONObject.fromObject(hashMap));
        
        //创建一个JsonArray方法1
        JSONArray jsonArray = new JSONArray();
        jsonArray.add(0, "xxb");
        jsonArray.add(1, "27");
        System.out.println("jsonArray1:" + jsonArray);
        
        //创建JsonArray方法2
        ArrayList<String> arrayList = new ArrayList<String>();
        arrayList.add("xxb");
        arrayList.add("27");
        System.out.println("jsonArray2:" + JSONArray.fromObject(arrayList));
        
        //如果JSONArray解析一个HashMap,则会将整个对象的放进一个数组的值中
        System.out.println("jsonArray FROM HASHMAP:" + JSONArray.fromObject(hashMap));
        
        //组装一个复杂的JSONArray
        JSONObject jsonObject2 = new JSONObject();
        jsonObject2.put("UserName", "xxb");
        jsonObject2.put("age", "27");
        jsonObject2.element("Array", arrayList);
        System.out.println("jsonObject2:" + jsonObject2);
                
    }
}

结果:

jsonObject1:{"UserName":"xxb","age":"27"}
jsonObject2:{"age":"27","UserName":"xxb"}
jsonArray1:["xxb","27"]
jsonArray2:["xxb","27"]
jsonArray FROM HASHMAP:[{"age":"27","UserName":"xxb"}]
jsonObject2:{"UserName":"ZHULI","age":"30","Array":["ZHULI","30","ALI"]}

二、解析JSON字符串

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


public class Test {

    public static void main(String[] args) {
        String jsonString = "{"UserName":"xxb","age":"27","Array":["xxb","27"]}";
        //将Json字符串转为java对象
        JSONObject obj = JSONObject.fromObject(jsonString);
        //获取Object中的UserName
        if (obj.has("UserName")) {
            System.out.println("UserName:" + obj.getString("UserName"));
        }
        //获取ArrayObject
        if (obj.has("Array")) {
            JSONArray transitListArray = obj.getJSONArray("Array");
            for (int i = 0; i < transitListArray.size(); i++) {
                System.out.print("Array:" + transitListArray.getString(i) + " ");
            }
        }
    }
}

结果:

UserName:xxb

Array:xxb Array:27