根据json路径规则获取json任意节点信息（工具向）_java 指定节点path 获取json

做这个的目的？

        基于接口的质量检核，需要对接口数据进行标准化（类似表结构）。由于接口数据由数据共享平台拦截接口保存数据，故各种接口的返回数据形式各不相同，为了质量检核得以实现，对拦截的接口数据进行相应的实体抽取得到标准化数据

举个栗子

        假设有如下数据：

{
  "code": "200", 
  "total": 1, 
  "data": [
    {
     "people":{
     	"name":"SS",
       "age":10,
       "sex":"F",
       "address":{
         "country":"中国",
         "city":"重庆市",
       	  "street":"皇室桀骜"
       }
     }
    },{
     "people":{
     	"name":"SS",
       "age":10,
       "sex":"F",
        "address":{
         "country":"中国",
         "city":"重庆市",
       	  "street":"皇室桀骜"
       }
     }
    },{
     "people":{
     	"name":"SS",
       "age":10,
       "sex":"F",
        "address":{
         "country":"中国",
         "city":"重庆市",
       	  "street":"皇室桀骜"
       }
     }
    },{
     "people":{
     	"name":"SS",
       "age":10,
       "sex":"F",
        "address":{
         "country":"中国",
         "city":"重庆市",
       	  "street":"皇室桀骜"
       }
     }
    }
  ]
}

        假设我需要拿到address的相关信息。我的json路径就是data.people.address

但是需要对每个people进行解析取出address，所以为了快速取出数据，根据路径，定制了下面的规则。

        同样以取address为目标，规则路径为data[?].people.address ；data为key，[]代表数组，？代表data下的每一个对象都需要进行解析，如果为数字0，1，2则表示取第几个元素。

程序实现

        由于数据层级与数据是对象还是数组的不确定性，所以采用递归的方式进行实现

package org.zxhy.tool;
 
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
/**
 * @author Ryan
 * @version 1.0
 * @date 2021/9/9
 */
public class JSONUtil {
    private Pattern pattern = Pattern.compile("\\[.\\]");
    private String str = "{\n" +
            "  \"code\": \"200\", \n" +
            "  \"total\": 1, \n" +
            "  \"data\": [\n" +
            "    {\n" +
            "     \"people\":{\n" +
            "     \t\"name\":\"SS\",\n" +
            "       \"age\":10,\n" +
            "       \"sex\":\"F\",\n" +
            "       \"address\":{\n" +
            "         \"country\":\"中国\",\n" +
            "         \"city\":\"重庆市\",\n" +
            "       \t  \"street\":\"皇室桀骜\"\n" +
            "       }\n" +
            "     }\n" +
            "    },{\n" +
            "     \"people\":{\n" +
            "     \t\"name\":\"SS\",\n" +
            "       \"age\":10,\n" +
            "       \"sex\":\"F\",\n" +
            "        \"address\":{\n" +
            "         \"country\":\"中国\",\n" +
            "         \"city\":\"重庆市\",\n" +
            "       \t  \"street\":\"皇室桀骜\"\n" +
            "       }\n" +
            "     }\n" +
            "    },{\n" +
            "     \"people\":{\n" +
            "     \t\"name\":\"SS\",\n" +
            "       \"age\":10,\n" +
            "       \"sex\":\"F\",\n" +
            "        \"address\":{\n" +
            "         \"country\":\"中国\",\n" +
            "         \"city\":\"重庆市\",\n" +
            "       \t  \"street\":\"皇室桀骜\"\n" +
            "       }\n" +
            "     }\n" +
            "    },{\n" +
            "     \"people\":{\n" +
            "     \t\"name\":\"SS\",\n" +
            "       \"age\":10,\n" +
            "       \"sex\":\"F\",\n" +
            "        \"address\":{\n" +
            "         \"country\":\"中国\",\n" +
            "         \"city\":\"重庆市\",\n" +
            "       \t  \"street\":\"皇室桀骜\"\n" +
            "       }\n" +
            "     }\n" +
            "    }\n" +
            "  ]\n" +
            "}";
 
    public static void main(String[] args) {
        JSONUtil util = new JSONUtil();
        JSONObject obj = (JSONObject) JSONObject.parse(util.str);
        List<String> list = util.splitDataByPath(obj,"data[?].people.address",new ArrayList<>());
        for(String s:list){
            System.out.println(s);
        }
    }
 
    private List<String> splitDataByPath(JSONObject object, String path, List<String> list)  {
        if(path == null||"".equals(path)){
            System.out.println("path 不能为空");
        }
        if(object == null){
            return  list;
        }
        int poz = path.indexOf(".");
        if(poz!=-1){
            String p = path.substring(0,poz);
            String idx = regexPath(p);
            //继续封装，递归
            String nextPath = path.substring(poz+1);
            if(idx==null){
                splitDataByPath(object.getJSONObject(p),nextPath,list);
            }else{
                JSONArray array = object.getJSONArray(p.substring(0,p.length()-3));
                if("?".equals(idx)){
                    //everyone should to do
                    for(Object o:array){
                        splitDataByPath((JSONObject)o,nextPath,list);
                    }
                }else {
                    //just get one
                    int index = Integer.valueOf(idx);
                    //防止下标越界
                    if(index<array.size()){
                        splitDataByPath((JSONObject) array.get(index),nextPath,list);
                    }
 
                }
            }
        }else{
            String idx = regexPath(path);
            //取数据，封装返回
            if(idx==null){
                list.add(object.getString(path));
            }else{
                JSONArray array = object.getJSONArray(path.substring(0,path.length()-3));
                if("?".equals(idx)){
                    //everyone should to do
                    for(Object o:array){
                        list.add(o.toString());
                    }
                }else {
                    //just get one
                    int index = Integer.valueOf(idx);
                    if(index<array.size()){
                        list.add(array.getString(index));
                    }
                }
            }
        }
        return list;
    }
 
    /**
     * 解析path，并判断是否为数组，及数组中的位置
     * @param path
     * @return
     */
    private String regexPath(String path){
        Matcher matcher = pattern.matcher(path);
        if(matcher.find()){
            String pos =  matcher.group();
            return pos.substring(1,2);
        }
        return  null;
    }
}

这里使用了fastjson，也可以使用其他json替换。最终得到的结果如下：

{"country":"中国","city":"重庆市","street":"皇室桀骜"}
{"country":"中国","city":"重庆市","street":"皇室桀骜"}
{"country":"中国","city":"重庆市","street":"皇室桀骜"}
{"country":"中国","city":"重庆市","street":"皇室桀骜"}