java - How to send Http POST request at every two minutes using JAX-RS?

Question

I am developing server side web services code. I am using JAX-RS as development framework.

So far I have created model classes and resources class that responds requested data to client.

Sample resource method...

@GET
@Path("/{userId}")
@Produces(MediaType.APPLICATION_JSON)
public User getUserDetails(@PathParam("userId") long id) {
    ..
    // some code here //
    ..
}

Basically, server responds the data or do some operations depends on the URI is been called by the client.

I want to make Http POST request to third-party server at every two minutes from the moment server starts. But I dont know where should I write that code (as I said, methods executions depends on the URI is been called).

So, where should I write the code that starts executing when the server starts and ends when server stops.

How to send Http request at every two minutes interval ?

Answer 1

You should be able to do that with a combination of Quartz and ServletContextListener.

You will need to create a job, trigger and scheduler to make your code run after every two minutes and a listener class that implements ServletContextListener interface.

Your code would look something like this:

Job Class:

 package com.example;

    import org.quartz.Job;
    import org.quartz.JobExecutionContext;
    import org.quartz.JobExecutionException;

    public class ExampleJob implements Job
    {
        public void execute(JobExecutionContext context) throws JobExecutionException {
                // Code to make POST call here
    }

ServletContextListener

package com.example;

public class ExampleListener implements javax.servlet.ServletContextListener {

   public void contextInitialized(ServletContext context) {
      JobDetail job = JobBuilder.newJob(ExampleJob.class)
            .withIdentity("exampleJob", "group").build();
      // Trigger
      Trigger trigger = TriggerBuilder
            .newTrigger()
            .withIdentity("exampleTrigger", "group")
            .withSchedule(
                SimpleScheduleBuilder.simpleSchedule()
                    .withIntervalInSeconds(120).repeatForever())
            .build();
      // Scheduler
        Scheduler scheduler = new StdSchedulerFactory().getScheduler();
        scheduler.start();
        scheduler.scheduleJob(job, trigger);

   }
}

And add this in web.xml:

<listener>
    <listener-class>com.example.ExampleListener</listener-class>
</listener>

or if you are using servlet container 3.x, you can skip the web.xml modification by annotating the listener class with @WebListener