07
Mar
roofs
Recently came across a problem whereby the quartz scheduler could not recreate a new log4j FileAppender log when the job is call again.
Googled a bit and found out a couple of solutions such as using a custom log4j classes, which create a seperate thread when being called in quartz scheduler.
I find that it is too complex and had try several ways to recreate the log file inside Quartz.
And finally came up with this one line of code.
Before I begin, let’s take a look at my log4j config.
This log4j config will create a simple console system out logger and also a FileAppender logger.
For my case, I want to re-create a new log file whenever this job is run.
log4j.rootLogger=INFO, stdout log4j.additivity.stdout=false log4j.additivity.joblog=false log4j.appender.ROOT.layout.ConversionPattern=[%d] %t %c %-5p - %m%n #console log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%d %p - %m%n #per job execution log log4j.logger.com.yourcompany=INFO, joblog log4j.appender.joblog=org.apache.log4j.FileAppender log4j.appender.joblog.layout=org.apache.log4j.PatternLayout log4j.appender.joblog.File=../jobtemp.log log4j.appender.joblog.Append=false log4j.appender.joblog.layout.ConversionPattern=%d %p - %m%n
and here’s the schedule job
public class ScheduleJob implements StatefulJob {
private static Logger logger = Logger.getLogger(ScheduleJob.class);
public void startJob() throws SchedulerException{
Scheduler scheduler =
StdSchedulerFactory.getDefaultScheduler();
scheduler.start();
}
public void execute(JobExecutionContext context)
throws JobExecutionException {
//reset log4j config for FileAppender
PropertyConfigurator.configure("../conf/log4j.properties");
RunJobImmediately newJob = new RunJobImmediately();
newJob.performJob();
}
public static void main(String args[]){
try{
ScheduleJob scheduleJob = new ScheduleJob();
scheduleJob.startJob();
}catch(Exception e){
logger.error(e);
}
}
}
and finally the one line of code to recreate the log file.
Apparently, this line will somehow ‘reload’ the log4j utitlies, which thus recreate the FileAppender logger to re-create the log file.
PropertyConfigurator.configure("../conf/log4j.properties");
Feel free to let me know if there is any performance issues or it is not working at your side.
27
Feb
crossing road
Taken @ phuket
I noticed that some of the computer which I remote desktop to, could not be shutdown or restart. Instead of the normal shutdown or logoff, you will see a log off and disconnect button.
I googled out and the easiest way to restart/shutdown such computer via remote desktop is to bring out the user menu and shutdown/restart from there.
To do it, you simply press Ctrl + Alt + End key. Cheers.
Here’s the code snippets to display the number of running threads in your java program.
It’s good to use it to track your resources.
int activeCount = Thread.activeCount();
System.out.println("total active = " + activeCount);
Thread[] threads = new Thread[activeCount];
Thread.enumerate(threads);
System.out.println("before");
for (int j=0; j<threads.length; j++) {
System.out.println(threads[j].toString());
}
//run your classes
Benny benny = new Benny();
activeCount = Thread.activeCount();
System.out.println("total active = " + activeCount);
threads = new Thread[activeCount];
System.out.println("after");
Thread.enumerate(threads);
for (int i=0; i<threads.length; i++) {
System.out.println(threads[i].toString());
}
