threadpool in java code example

Example 1: java use thread pool executor

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

public class TestThread {
	
   public static void main(final String[] arguments) throws InterruptedException {
      ThreadPoolExecutor executor = (ThreadPoolExecutor)Executors.newCachedThreadPool();

      //Stats before tasks execution
      System.out.println("Largest executions: "
         + executor.getLargestPoolSize());
      System.out.println("Maximum allowed threads: "
         + executor.getMaximumPoolSize());
      System.out.println("Current threads in pool: "
         + executor.getPoolSize());
      System.out.println("Currently executing threads: "
         + executor.getActiveCount());
      System.out.println("Total number of threads(ever scheduled): "
         + executor.getTaskCount());

      executor.submit(new Task());
      executor.submit(new Task());

      //Stats after tasks execution
      System.out.println("Core threads: " + executor.getCorePoolSize());
      System.out.println("Largest executions: "
         + executor.getLargestPoolSize());
      System.out.println("Maximum allowed threads: "
         + executor.getMaximumPoolSize());
      System.out.println("Current threads in pool: "
         + executor.getPoolSize());
      System.out.println("Currently executing threads: "
         + executor.getActiveCount());
      System.out.println("Total number of threads(ever scheduled): "
         + executor.getTaskCount());

      executor.shutdown();
   }  

   static class Task implements Runnable {

      public void run() {

         try {
            Long duration = (long) (Math.random() * 5);
            System.out.println("Running Task! Thread Name: " +
               Thread.currentThread().getName());
            TimeUnit.SECONDS.sleep(duration);
            System.out.println("Task Completed! Thread Name: " +
               Thread.currentThread().getName());
         } catch (InterruptedException e) {
            e.printStackTrace();
         }
      }
   }
}

Example 2: thread pool java

package com.journaldev.threadpool;

public class WorkerThread implements Runnable {
  
    private String command;
    
    public WorkerThread(String s){
        this.command=s;
    }

    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName()+" Start. Command = "+command);
        processCommand();
        System.out.println(Thread.currentThread().getName()+" End.");
    }

    private void processCommand() {
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    @Override
    public String toString(){
        return this.command;
    }
}