{
 "button": [
  {
   "type": "click",
   "name": "今日歌曲",
   "key": "V1001_TODAY_MUSIC"
  },
  {
   "name": "菜單",
   "sub_button": [
    {
     "type": "view",
     "name": "搜索",
     "url": "http://www.soso.com/"
    },
    {
     "type": "miniprogram",
     "name": "wxa",
     "url": "http://mp.weixin.qq.com",
     "appid": "wx286b93c14bbf93aa",
     "pagepath": "pages/lunar/index"
    },
    {
     "type": "click",
     "name": "贊一下我們",
     "key": "V1001_GOOD"
    }
   ]
  }
 ]
}

  <dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>fastjson</artifactId>
   <version>1.2.54</version>
  </dependency>
  <dependency>
   <groupId>org.apache.commons</groupId>
   <artifactId>commons-io</artifactId>
   <version>1.3.2</version>
  </dependency>

package com.jeff.demo;
import java.io.InputStream;
import org.apache.commons.io.IOUtils;
import com.alibaba.fastjson.JSONObject;
public class FileDemo3 {
	public static JSONObject fileToJson(String fileName) {
		JSONObject json = null;
		try (
			InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream(fileName);
		) {
			json = JSONObject.parseObject(IOUtils.toString(is, "utf-8"));
		} catch (Exception e) {
			System.out.println(fileName + "文件讀取異常" + e);
		}
		return json;
	}
	public static void main(String[] args) {
		String fileName = "doc/demo.json";
		JSONObject json = FileDemo3.fileToJson(fileName);
		System.out.println(json);
	}
}

String jsonFilePath = "C:/a.json";
File file = new File(jsonFilePath );
String input = FileUtils.readFileToString(file,"UTF-8");
JSONObject obj = new JSONObject(input);