[大数据]Java使用fastJson解析复杂Json

实现字符串方式调用复杂json

传值 "freeform.test2[0].test3" 调用返回的是键 test3的值对象

思想是利用 for 中变量迭代

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;

import java.io.PrintStream;

public class Demo2 {
        public static int getIndex(String str){
            String indexSub = str.substring(str.indexOf("["));
            return Integer.parseInt(indexSub.substring(1,indexSub.length()-1));
        }

        public static Object getVal(JSONObject js,String key){
            System.out.println("js is:");
            System.out.println(js.toString());
            if(key.endsWith("]")){
                int index = getIndex(key);
                System.out.println("index is "+String.valueOf(index));
                System.out.println("key is "+String.valueOf(key.substring(0,key.indexOf("["))));
                System.out.println();
                return js.getJSONArray(key.substring(0,key.indexOf("["))).get(index);
            }else {
                System.out.println("else key is "+key);
                Object o = js.get(key);
                System.out.println("o is "+o.toString());
                return o;
            }
        }

        public static Object getJsonVal(Object obj,String[] keyStr){
            Object iter = getVal((JSONObject) obj, keyStr[0]);;
            System.out.println("keyStr is:");
            for (String s :
                    keyStr) {
                System.out.print(s+"\t");
            }
            System.out.println("\n========================================");
            if (keyStr.length==1){
                System.out.println("iter is "+ iter.toString());
                return iter;

            }else {
            for(int i=1;i<keyStr.length;i++){
                if(iter instanceof JSONObject){
                    iter  = getVal((JSONObject) iter,keyStr[i]);
                }
            }}
            return iter;
        }
        public static void main(String[] args) {
            String body = "{\n" +
                    "    \"Content-Length\":\"87\",\n" +
                    "    \"Content-Type\":\"application/json\",\n" +
                    "    \"freeform\":{\n" +
                    "        \"test1\":\"test1val\",\n" +
                    "        \"test2\":[\n" +
                    "            {\n" +
                    "                \"test3\":\"test3val\"\n" +
                    "            },\n" +
                    "            {\n" +
                    "                \"test4\":{\n" +
                    "                    \"test5\":\"test5val\",\n" +
                    "                    \"test6\":\"test6val\"\n" +
                    "                }\n" +
                    "            }\n" +
                    "        ]\n" +
                    "    }\n" +
                    "}";
            String str = "freeform.test2[0].test3";
//            String str = "Content-Type";
            Object jsonVal = getJsonVal(JSON.parseObject(body), str.split("\\."));
            System.out.println("---------------------------------------");
            System.out.println(jsonVal.toString());
//            JSONObject js = JSON.parseObject(body);
//            JSONObject freeform = js.getJSONObject("freeform");
//            JSONObject test2 = freeform.getJSONArray("test2").getJSONObject(0);
//            String test4 = test2.getString("test4");


//            System.out.println(getIndex("test[5]"));
        }

}