使用java.io.RandomAccessFile更改文本文件的内容

原文本内容:

2020-01-21 08:31:08.520 [main] INFO  logbackCfg.App -秦时明月汉时关
2020-01-21 08:31:08.521 [main] ERROR logbackCfg.App -万里长征人未还
2020-01-21 08:31:08.521 [main] DEBUG logbackCfg.App -但使龙城飞将在
2020-01-21 08:31:08.521 [main] TRACE logbackCfg.App -不教胡马度阴山
2020-01-21 08:31:10.311 [main] INFO  logbackCfg.App2 -九里山前作战场
2020-01-21 08:31:10.317 [main] ERROR logbackCfg.App2 -牧童拾得旧刀枪
2020-01-21 08:31:10.317 [main] DEBUG logbackCfg.App2 -微风吹皱乌江水
2020-01-21 08:31:10.317 [main] TRACE logbackCfg.App2 -恰似虞姬别霸王
2020-01-21 08:31:13.521 [main] INFO  logbackCfg.App -秦时明月汉时关
2020-01-21 08:31:13.521 [main] ERROR logbackCfg.App -万里长征人未还
2020-01-21 08:31:13.521 [main] DEBUG logbackCfg.App -但使龙城飞将在
2020-01-21 08:31:13.521 [main] TRACE logbackCfg.App -不教胡马度阴山
2020-01-21 08:31:14.262 [main] INFO  logbackCfg.NewDayThread -万里赴戎机，关山度若飞。
2020-01-21 08:31:14.267 [main] ERROR logbackCfg.NewDayThread -朔气传金柝，寒光照铁衣。
2020-01-21 08:31:14.267 [main] DEBUG logbackCfg.NewDayThread -将军百战死，壮士十年归。

使用如下程序进行替换:

package randomaccessfile;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;

public class RndAccessFile {
    public static void main(String[] args) {
        RandomAccessFile rndFile = null;
        try {
            rndFile = new RandomAccessFile("D:\\logs\\rndTest.txt", "rw");

            String line = null;
            long lastPoint = 0; 

            while ((line = rndFile.readLine()) != null) {
                final long point = rndFile.getFilePointer();

                // ASCII字符替换
                if(line.contains("ERROR")){
                    String str=line.replace("ERROR", "error");
                    rndFile.seek(lastPoint);
                    rndFile.writeBytes(str);
                }

                // UTF8字符替换
                String utf8 = new String(line.getBytes("ISO-8859-1"),"UTF-8");
                if(utf8.contains("秦时明月汉时关")){
                    String str=utf8.replace("秦时明月汉时关", "葡萄美酒夜光杯");// Must be same length
                    rndFile.seek(lastPoint);
                    rndFile.write(str.getBytes("UTF-8"));
                }

                lastPoint = point;
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                rndFile.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

替换结果:

2020-01-21 08:31:08.520 [main] INFO  logbackCfg.App -葡萄美酒夜光杯
2020-01-21 08:31:08.521 [main] error logbackCfg.App -万里长征人未还
2020-01-21 08:31:08.521 [main] DEBUG logbackCfg.App -但使龙城飞将在
2020-01-21 08:31:08.521 [main] TRACE logbackCfg.App -不教胡马度阴山
2020-01-21 08:31:10.311 [main] INFO  logbackCfg.App2 -九里山前作战场
2020-01-21 08:31:10.317 [main] error logbackCfg.App2 -牧童拾得旧刀枪
2020-01-21 08:31:10.317 [main] DEBUG logbackCfg.App2 -微风吹皱乌江水
2020-01-21 08:31:10.317 [main] TRACE logbackCfg.App2 -恰似虞姬别霸王
2020-01-21 08:31:13.521 [main] INFO  logbackCfg.App -葡萄美酒夜光杯
2020-01-21 08:31:13.521 [main] error logbackCfg.App -万里长征人未还
2020-01-21 08:31:13.521 [main] DEBUG logbackCfg.App -但使龙城飞将在
2020-01-21 08:31:13.521 [main] TRACE logbackCfg.App -不教胡马度阴山
2020-01-21 08:31:14.262 [main] INFO  logbackCfg.NewDayThread -万里赴戎机，关山度若飞。
2020-01-21 08:31:14.267 [main] error logbackCfg.NewDayThread -朔气传金柝，寒光照铁衣。
2020-01-21 08:31:14.267 [main] DEBUG logbackCfg.NewDayThread -将军百战死，壮士十年归。

参考资料:

https://www.cnblogs.com/wangjinyu/p/10803596.html