What would be the best way to schedule an event to run every Monday at 00:00?
Note though the app is running 24/7. So OS based schedulers such as cron are not needed.
You could embed a Quartz Scheduler in your Java app if it's a long running app. Quartz is a very flexible/powerful scheduler that can be configured in many ways.
Alternatively, if you simply want to run a Java process at a particular time then you should look at cron.
Edit: Given that your app is 24/7 (noting comments above), Quartz is definitely the way forward.
I think cron4J may be your best bet. You can then configure it to run at ceratin times.
Us the OS scheduler; either cron, Windows task scheduler or similar
Related
I have a requirement to send SOAP message to lot of devices everyday at a certain time. I will get the time from a tomcat parameter in web.xml. Something like;
<context-param>
<param-name>DailyTime</param-name>
<param-value>04:00</param-value>
</context-param>
I must create a separate thread that sends the messages. Time will be in 24-hrs format.
The problem is, as a starter i have no idea where to start or how to do it. Can you guys please point me in the right direction or give me some tips, which will help me greatly.
Thank You Everyone :)
You have several options. The two I've used most in the past are:
1) Schedule a cron job to run at the time(s) you want, and have it call an executable java class / jar file.
2) Use a scheduler library like Quartz
Regarding #1 - this assumes you're using a *nix system. If you're using Windows, you can schedule tasks through the Task Scheduler.
Regarding #2 - this gives you more flexibility on the conditions of running a task/job. For example, you could schedule a job to run every 1 minute, but not to start a new job until any existing job is complete.
Anecdotal remark from a version of Quartz circa 2006 - on WebSphere, it seems that my quartz jobs were getting executed by some background thread that made jobs take hours which should have only taken a few seconds. But that was almost a decade ago, and certainly quartz (and hopefully websphere) have vastly improved.
I have a task in which, I have monitor a folder for new files and upload its content to database. For this, I have written a Java Program, created an executable JAR and scheduled it for execution after fix interval i.e after 5 min. using Windows Task Scheduler on Windows 7.
I have to ask about reliability of this approach. How reliable is Task Scheduler? Is there any better approach like creating a windows service ,etc by which I can schedule my Program/ JAR.
Any suggestions would be appreciated.
Thanks!
Best Regards,
Kunal
Take a look on Quartz
Quartz Scheduler is a Java-based open-source job scheduling service which is used in most of the applications to schedule their timely jobs.
I have a .bat file in a Windows machine that starts our program by calling a main class of a Java executable(.Jar)
Now I need to run this every 30 mins.
I gone through several ways of doing it, but unable to decide which is better.
Scheduling through Windows scheduler or Using Java Timer. Which one to choose?
I want only one instance of the process running. If the previous process doesnt complete within 30min, i could wait.
Please let me know what to go for, based on my use case.
Thanks in advance.
You're better off using the Windows Scheduler. If there's a real risk of the process taking too long, you can create a file, or open a socket while the process is running and when another one tries to start up, it can detect that and simply quit. This would make it "miss" the 30m window (i.e. if the first job started at 12 and finished at 12:35, the next job would not start until 1).
But this way you don't have to worry at all about setting up long running processes, starting and stopping the java service, etc. The Windows scheduler just makes everything easier for something like this.
TimerTask is not a scheduling system, it is a library that provides tools for in-app scheduling. Seems that for your use-case you need a the system: you need it to run whether or not your app is running, you need reporting, etc. Windows Scheduler (or cron on unix/linux) is more appropriate for your needs.
I have a java application which downloads a file from an FTP server and I need it to run daily. I was just wondering what the best method to schedule it to run would be. The options I am currently considering are the Windows scheduler and Java timer task.
At the moment I have the windows scheduler pointing at a batch file which runs my program.
If anybody has any knowledge in the area I would appreciate to hear from you!!
Look at AT TASKS on windows and CRON JOBS on unix. These can run your Java program.
You should also take a look at Quartz which is a Java-based job scheduling system.
You can also get help from this link.
Why don't you use #Schedule abilities of EJB 3?
If your server is not EJB 3 - capable, use Quartz, Timer and TimerTask classes.
I've created a small java program and I want to launch it everyday at 1 o'clock.
I can add it windows task plannifier and it works very well but I want to do it with java.
The java timer task seems to be not good.
I heard about Quartz and when I try their it seems to be complicated for me or I don't find the simple example or tutorial.
Can anyone know some good tutorial or example code easier than the Quartz's site.
Or redirect me to some other site.
Both Quartz and the built in Timer class are not built to start your whole application. They are built to run some specified tasks according to some schedule as long as your application is running.
To actually start your application at a specified time, an external resource will be necessary (unless you want your application to run at all times and only do some activity ever so often).
For that purpose the Windows Task Scheduler is sufficient.
Quartz
Quartz is a full-featured, open source job scheduling service that can be integrated with, or used along side virtually any Java EE or Java SE application.
The basic terminology are (at very basic view):
Scheduler : You can think of this as the core container or something that is the base of quartz.
Job : You can think this as the task we need to do , out simple java Class
Trigger : Something that will make Job to run on scheduler, there are two types of trigger with quartz
Simple Trigger (you can configure it with delay between execution, delay for first execution . . and many such params)
Cron-Trigger : Here you can configure trigger with cron expression.
Also See
Quartz cook book
Quartz : Best practices
small java program and I want to launch it everyday at 1 o'clock
cronjob in unix
Scheduling a Job For a Specific Time Every Day
The basic usage of cron is to execute a job in a specific
time as shown below.This will execute the sample_java_program
everyday at 1am.
30 01 * * * java /home/suresh/sample_java_program
* 30 – 30th Minute
* 01 – 01 AM
* * – every Day
* * – every Month
* * – Every day of the week
Scheduling in windows this link might help u .
cron4j is another one
When you say:
Both Quartz and the built in Timer class are not built to start your whole application.
So i could never launch my whole java program with Quartz or Timer.
it only launches some speicfic task while my prg is running?
so it's better to keep Windows task Scheduler?
ok thank you