Java 读取json

代码：

package com.util;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;


import java.io.*;
public class Josn_load {
     //读取json文件
    public static String readJsonFile(String fileName) {
        String jsonStr = "";
        try {
            File jsonFile = new File(fileName);
            FileReader fileReader = new FileReader(jsonFile);
            Reader reader = new InputStreamReader(new FileInputStream(jsonFile),"utf-8");
            int ch = 0;
            StringBuffer sb = new StringBuffer();
            while ((ch = reader.read()) != -1) {
                sb.append((char) ch);
            }
            fileReader.close();
            reader.close();
            jsonStr = sb.toString();
            return jsonStr;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }
    
    public static void main(String[] args) {
        String path = "E:\Myeclipse\WorkPlace_graduate\基于合同纠纷知识图谱构建及应用\WebContent\data\data_node.json";
        String s = readJsonFile(path);
        JSONObject jobj = JSON.parseObject(s);
        JSONArray Nodes = jobj.getJSONArray("Nodes");//构建JSONArray数组
        for (int i = 0 ; i < Nodes.size();i++){
            JSONObject key = (JSONObject)Nodes.get(i);
            String symbolSize = (String)key.get("name");
            System.out.println(key.get("symbolSize"));
            System.out.println(symbolSize);
        }
    }
}

JSON：