package backgroundProcesses;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.TimerTask;

public class MinhaThread implements Runnable {

    @Override
    public void run() {
        Calendar cal = Calendar.getInstance();
        SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
        System.out.println("FOI, COMEÇOOU A THREAD: " +  sdf.format(cal.getTime()));
        int i = 0;
        while(i < 1000000000) {
            int a = 1;
        }

        System.out.println("CHEGOU AO FIM");
    }

}

package backgroundProcesses;

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;

@WebListener
public class ExecutorThreads implements ServletContextListener {

     private ScheduledExecutorService scheduler;


     @Override
    public void contextInitialized(ServletContextEvent arg0) {
        // TODO Auto-generated method stub
        scheduler = Executors.newScheduledThreadPool(4);
        scheduler.scheduleAtFixedRate(new MinhaThread(), 0, 10, TimeUnit.SECONDS);
    }

    @Override
    public void contextDestroyed(ServletContextEvent arg0) {
        // TODO Auto-generated method stub
        scheduler.shutdownNow();
    }



}

@WebListener
public class Executor implements ServletContextListener {

    private ScheduledExecutorService scheduler;
    private ExecutorService executorService;

    @Override
    public void contextInitialized(ServletContextEvent arg0) {
        // TODO Auto-generated method stub

        executorService = Executors.newCachedThreadPool();
        scheduler = Executors.newScheduledThreadPool(4);

        scheduler.scheduleWithFixedDelay(new Runnable() {
            @Override
            public void run() {
                executorService.submit(new MinhaThread());
            }
        }, 0, 10, TimeUnit.SECONDS);

    @Override
    public void contextDestroyed(ServletContextEvent arg0) {
        // TODO Auto-generated method stub
        scheduler.shutdownNow();
    }

}

package backgroundProcesses;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.TimerTask;

public class MinhaThread implements Runnable {

    @Override
    public void run() {
        Calendar cal = Calendar.getInstance();
        SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
        System.out.println("FOI, COMEÇOOU A THREAD: " +  sdf.format(cal.getTime()));
        int i = 0;
        while(i < 1000000000) {
            int a = 1;
        }

        System.out.println("CHEGOU AO FIM");
    }

}

package backgroundProcesses;

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class OutraThread implements Runnable {

    @Override
    public void run() {
        // TODO Auto-generated method stub
        System.out.println("ENTROU NA THREAD SECUNDARIA");
        new Thread(new MinhaThread()).start();

    }

}

package backgroundProcesses;

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;



@WebListener
public class Executor implements ServletContextListener {

     private ScheduledExecutorService scheduler;


     @Override
    public void contextInitialized(ServletContextEvent arg0) {
        // TODO Auto-generated method stub
        scheduler = Executors.newScheduledThreadPool(4);
        scheduler.scheduleAtFixedRate(new OutraThread(), 0, 10, TimeUnit.SECONDS); //roda a qualidade a cada 5 minutos.
    }

    @Override
    public void contextDestroyed(ServletContextEvent arg0) {
        // TODO Auto-generated method stub
        scheduler.shutdownNow();
    }



}

ENTROU NA THREAD SECUNDARIA
FOI, COMEÇOOU A THREAD: 11:54:33
ENTROU NA THREAD SECUNDARIA
FOI, COMEÇOOU A THREAD: 11:54:43
ENTROU NA THREAD SECUNDARIA
FOI, COMEÇOOU A THREAD: 11:54:53
ENTROU NA THREAD SECUNDARIA
FOI, COMEÇOOU A THREAD: 11:55:03
ENTROU NA THREAD SECUNDARIA
FOI, COMEÇOOU A THREAD: 11:55:13
ENTROU NA THREAD SECUNDARIA
FOI, COMEÇOOU A THREAD: 11:55:23