java读取文件数据

直接上代码，拿走可用。读取几百兆的大文件也么得问题~

package com.test.util;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import java.io.*;

/**
 * Json读取工具类
 *
 * @author yyh
 */
public class JsonFileUtil {

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

    public static void main(String[] args) {
        File file = new File("D:/test.json");
        String readJsonFile = readJsonFile(file);
        System.out.println(readJsonFile);
    }
    /**
     * 读取json文件
     *
     * @param jsonFile json文件
     * @return 返回json字符串
     */
    public static String readJsonFile(File jsonFile) {
        String jsonStr;
        logger.info("————开始读取" + jsonFile.getPath() + "文件————");
        try {
            BufferedInputStream fis = new BufferedInputStream(new FileInputStream(jsonFile));
            BufferedReader reader = new BufferedReader(new InputStreamReader(fis, "utf-8"), 5 * 1024 * 1024);// 5M缓冲
            StringBuilder sb = new StringBuilder();
            String line = "";
            while ((line = reader.readLine()) != null) {
                //每一行数据
                sb.append(line);
            }
            fis.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;
        }
    }

}