How to implement scheduled deletion of old logs in log4…

To achieve the automatic deletion of old log files in log4j, you can use log4j’s RollingFileAppender and DailyRollingFileAppender together with a scheduling framework like Quartz.

1. Set up a RollingFileAppender or DailyRollingFileAppender:
   In the log4j.properties file, configure a RollingFileAppender or DailyRollingFileAppender and define the file name and file rolling strategy. For example:

log4j.appender.myAppender=org.apache.log4j.RollingFileAppender
log4j.appender.myAppender.File=/path/to/log/file.log
log4j.appender.myAppender.MaxFileSize=5MB
log4j.appender.myAppender.MaxBackupIndex=10
log4j.appender.myAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.myAppender.layout.ConversionPattern=%d [%t] %-5p %c{1} - %m%n

MaxFileSize indicates the maximum size of an individual log file, while MaxBackupIndex represents the number of backup files to retain.

1. Set up a scheduled task:
   Utilize a scheduling framework (such as Quartz) to create a task that automatically deletes old log files. For example:

import org.quartz.*;
import org.quartz.impl.StdSchedulerFactory;

public class LogCleanupJob implements Job {
    public void execute(JobExecutionContext context) throws JobExecutionException {
        // 删除旧日志文件的逻辑
        // ...
    }

    public static void main(String[] args) throws SchedulerException {
        JobDetail job = JobBuilder.newJob(LogCleanupJob.class)
                .withIdentity("logCleanupJob", "logCleanupGroup")
                .build();

        Trigger trigger = TriggerBuilder.newTrigger()
                .withIdentity("logCleanupTrigger", "logCleanupGroup")
                .startNow()
                .withSchedule(CronScheduleBuilder.dailyAtHourAndMinute(0, 0)) // 每天0点执行
                .build();

        Scheduler scheduler = new StdSchedulerFactory().getScheduler();
        scheduler.start();
        scheduler.scheduleJob(job, trigger);
    }
}

In the execute method, write the logic to delete old log files, using the File class in Java to delete files.

1. Set up log4j to automatically delete old logs on a scheduled basis by configuring a timed task Appender in the log4j.properties file.

log4j.appender.cleanupAppender=org.apache.log4j.net.SocketAppender
log4j.appender.cleanupAppender.Port=4712
log4j.appender.cleanupAppender.RemoteHost=localhost
log4j.appender.cleanupAppender.ReconnectionDelay=10000
log4j.appender.cleanupAppender.Application=LogCleanupJob

In the LogCleanupJob class, the logic for scheduled deletion of old logs can be triggered by using the SocketAppender.

By following the steps above, you can achieve the functionality of log4j automatically deleting old logs. Please note that you need to configure the log4j.properties file and the relevant configurations of the scheduling framework.