import org.apache.logging.log4j.LogManager;

import org.apache.logging.log4j.Logger;

import java.io.*;

/**

 * Json读取工具类

 */

public class JsonUtil {

    private static final Logger logger = LogManager.getLogger(JsonUtil.class);

    /**

     * 读取json文件

     * @param fileName json文件名

     * @return 返回json字符串

     */

    public String readJsonFile(File jsonFile) {

        String jsonStr = "";

        logger.info("————开始读取" + jsonFile.getPath() + "文件————");

        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();

            logger.info("————读取" + jsonFile.getPath() + "文件结束!————");

            return jsonStr;

        } catch (Exception e) {

            logger.info("————读取" + jsonFile.getPath() + "文件出现异常，读取失败!————");

            e.printStackTrace();

            return null;

        }

    }

}

import com.alibaba.fastjson.JSON;

String jsonStr = jsonUtil.readJsonFile(file);

Map jsonMap = (Map) JSON.parse(jsonStr);