jdk8 獲取fastJson中所有的KEY

本文采用java8forEach的方式，遍歷JSON中所有的KEY。

JSON格式如下：

"{"name":"tom","age":18,"email":"[email protected]","address":[{"province":"湖北省"},{"city":"武漢市"},{"disrtict":"武昌區"}]}

處理後得到如下結果：

address,addressprovincecitydisrtictname,nameage,ageemail

具體實現代碼如下：

package com.hyx.util;

import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;

import java.util.concurrent.atomic.AtomicInteger;

/**
 * JsonUtil
 *
 * @author HYX
 * @date 2020/5/18 21:40
 */
public class JsonUtil {
    /**
     * 遞歸讀取所有的key
     *
     * @param jsonObject 需要獲取key的
     */
    public static StringBuffer getAllKey(JSONObject jsonObject) {
        if (jsonObject == null || jsonObject.isEmpty()) {
            return null;
        }
        StringBuffer stringBuffer = new StringBuffer();
        int countKey=jsonObject.size();
        AtomicInteger count= new AtomicInteger();
        jsonObject.forEach((key,value)->{
            count.addAndGet(1);
            //判斷是否爲json最後一個key,如果不是則加逗號隔開
            if(count.get()!=countKey){
                stringBuffer.append(key).append(",");
            }
            stringBuffer.append(key);
            if (jsonObject.get(key) instanceof JSONObject) {
                JSONObject innerObject = (JSONObject) jsonObject.get(key);
                stringBuffer.append(getAllKey(innerObject));
            } else if (jsonObject.get(key) instanceof JSONArray) {
                JSONArray innerObject = (JSONArray) jsonObject.get(key);
                stringBuffer.append(getAllKey(innerObject));
            }
        });
        return stringBuffer;
    }

    public static StringBuffer getAllKey(JSONArray json1) {
        StringBuffer stringBuffer = new StringBuffer();
        if (json1 == null || json1.size() == 0) {
            return null;
        }
        json1.forEach(key->{
            if (key instanceof JSONObject) {
                JSONObject innerObject = (JSONObject) key;
                stringBuffer.append(getAllKey(innerObject));
            } else if (key instanceof JSONArray) {
                JSONArray innerObject = (JSONArray) key;
                stringBuffer.append(getAllKey(innerObject));
            }
        });
        return stringBuffer;
    }

    private final static String st1 = "{\"name\":\"tom\",\"age\":18,\"email\":\"[email protected]\",\"address\":[{\"province\":\"湖北省\"},{\"city\":\"武漢市\"},{\"disrtict\":\"武昌區\"}]}";
    private final static String st2 = "{name:\"tom\",age:18,email:\"[email protected]\"}";

    public static void main(String[] args) {
        System.out.println(st1);
        JSONObject jsonObject1 = JSONObject.parseObject(st1);
        StringBuffer stb = getAllKey(jsonObject1);
        System.err.println(stb);

    }
}