Solved

How to schedule a task using Java

Posted on 2008-06-25
7
1,052 Views
Last Modified: 2010-04-21
Hi Experts,

I have an application that gets inputs from some input files stored in a location and updates the DB. Now, I want to make this job using scheduler.

The important thing here is the schedule should be modifiable by an admin and the task must run at the scheduled time.

The application already existing is developed using Struts. The scheduler program should be a plug-in and should not affect other part of the application.

Can anyone please provide some code snippets and tell me how to do this.

Thanks.
Arjuna Rajan Rameshbabu
0
Comment
Question by:arjunarajan
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
7 Comments
 
LVL 13

Expert Comment

by:Bart Cremers
ID: 21863598
You could take a look at Opensymphony Quartz

http://www.opensymphony.com/quartz/
0
 
LVL 3

Expert Comment

by:shaz_
ID: 21863641
yeh like bart has already suggested pensympony quartz.. this blog tutorial seemed easy to read for me when i first tried it

http://gadjah-mada.blogspot.com/2006/06/opensymphony-quartz-on-tomcat-and.html
0
 
LVL 4

Accepted Solution

by:
aman123_123 earned 400 total points
ID: 21864308
Hi,

From what you have written I can say that you can make this a seperate application altogether. This application need not plug-in to your already running Stuts application.
You can use the Java Timer and Timer task classes to achieve the same.
For example the following code schedules to run every Sunday midnight.
You can also make this configurable.


import java.util.Calendar;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
 
public class ReadFileAndUpdateDb extends TimerTask {
 
  public void run() {
    //TODO  Code To  Read File And Update Db 
 }
 
}
 
class MainApplication {
 
  public static void main(String[] args) {
    Timer timer  new Timer();
    Calendar date = Calendar.getInstance();
    date.set(
      Calendar.DAY_OF_WEEK,
      Calendar.SUNDAY
    );
    date.set(Calendar.HOUR, 0);
    date.set(Calendar.MINUTE, 0);
    date.set(Calendar.SECOND, 0);
    date.set(Calendar.MILLISECOND, 0);
    // Schedule to run every Sunday in midnight
    timer.schedule(
      new ReadFileAndUpdateDb (),
      date.getTime(),
      1000 * 60 * 60 * 24 * 7
    );
  }
}

Open in new window

0
Business Impact of IT Communications

What are the business impacts of how well businesses communicate during an IT incident? Targeting, speed, and transparency all matter. Find out more in this infographic.

 

Author Comment

by:arjunarajan
ID: 21873180
Hi Aman,

Thank you for your response.

I have a program that does the DB updating part. Now, I want the same to be scheduled and also want it as a separate module as it is now.

How can I do this if I use the TimerTask since the TODO part comes inside the 'run()' method.

Also, how can I make the schedule to be modified.

Can you pls. give me a simple example on this.

Thanks,
Arjuna Rajan Rameshbabu
0
 
LVL 4

Expert Comment

by:aman123_123
ID: 21881005
The folling code will read from the configuration (properties) file.
class MainApplication {
 
  public static void main(String[] args) {
    Timer timer  new Timer();
    Properties properties = new Properties();
    try {
        properties.load(new FileInputStream("filename.properties"));
        DateFormat formatter = new SimpleDateFormat("yyyy.MM.dd.HH.mm.ss");
        Date date = (Date)formatter.parse("properties.getProperty("starttime")");
        int interval = 1000 * 60 * 60 * Integer.parseInt(properties.getProperty("interval"));
   // Schedule to run on specified time
    timer.schedule(
      new ReadFileAndUpdateDb (),
      date.getTime(),      
    );
 
    } catch (IOException e) {
    }
    } catch (ParseException e) {
    }
 
   }
}

Open in new window

0
 
LVL 4

Expert Comment

by:aman123_123
ID: 21881026
I forgot to mention that you will have to create a properties file which will contain the following entries.

starttime=//When you want your task to run for the first time.
interval=//How frequently you want the task to run

>> I have a program that does the DB updating part
If you call the function inside run method of ReadFileAndUpdateDb class. It will be scheduled the way you want it to.
0
 

Author Closing Comment

by:arjunarajan
ID: 31470476
I thank 'aman123_123' for his excellent support for the questions I asked on the solution he provided. I am very happy with the solution.

Thank you once again.
0

Featured Post

Online Training Solution

Drastically shorten your training time with WalkMe's advanced online training solution that Guides your trainees to action. Forget about retraining and skyrocket knowledge retention rates.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
check java version using powershell 13 437
How to execute a Python program and gather return output in Java 2 59
ArrayList Adding/settign data 3 33
Coding for the first time 9 95
Go is an acronym of golang, is a programming language developed Google in 2007. Go is a new language that is mostly in the C family, with significant input from Pascal/Modula/Oberon family. Hence Go arisen as low-level language with fast compilation…
Introduction This article is the first of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article explains our test automation goals. Then rationale is given for the tools we use to a…
Viewers learn about the “while” loop and how to utilize it correctly in Java. Additionally, viewers begin exploring how to include conditional statements within a while loop and avoid an endless loop. Define While Loop: Basic Example: Explanatio…
Viewers will learn one way to get user input in Java. Introduce the Scanner object: Declare the variable that stores the user input: An example prompting the user for input: Methods you need to invoke in order to properly get  user input:
Suggested Courses

738 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question