Identifying Even & Odd numbers by the help of different Thread

To Solve this problem I’ll be use thread synchronization with inter thread communication

Here I’ll be go step by step first I try with java 7 then I implement it via java 8

Even and Odd Printed by different thread

first I need to implement our class from Runnable interface (Here you can use callable or by extending thread class)

//java 7 approch
public class IdentifyEvenAndOddNumbersByThread implements Runnable{
    //i want to print from the 1 to the limit
    //i'll specify it in the while loop
    static int count=1;
     public Object object;

    public IdentifyEvenAndOddNumbersByThread(Object object) {
        this.object = object;
    }
    @Override
    public void run() {
        //upto 100
        while (count<=100){
            if (count%2==0 && Thread.currentThread().getName().equals("even"))
            {
                //we sync one after another by the help of synchronized () block
                synchronized (object){
                    System.out.println("Thread Name: "+Thread.currentThread().getName()+" Value: "+count);
                    //once i print it i need to immediately increase the count variable
                    count++;
                    //i use wait and notify for the inter thread communication
                    try {
                        object.wait();
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }
                }
            }
            if (count%2!=0 &&  Thread.currentThread().getName().equals("odd")){
                //this thread will print the odd number and notify once he is done
                //then again he will get a chance to execute
                synchronized (object){
                    System.out.println("Thread Name: "+Thread.currentThread().getName()+" Value: "+count);
                    //once i print it i need to immediately increase the count variable
                    count++;
                    object.notify();
                }
            }
        }
    }

    public static void main(String[] args) {
        //we need to declare an object here because we want to perform locking in the same object
        Object lock=new Object();
        Runnable object1=new IdentifyEvenAndOddNumbersByThread(lock);//now the parameter is crying why it is crying cz expecting the object
        Runnable object2=new IdentifyEvenAndOddNumbersByThread(lock);//now the parameter is crying why it is crying cz expecting the object

        //we can not execute runnable directly we need to pass runnable instance in the Thread class constructor
        //here i need to define the thread name i want to this thread as a even thread
        new Thread(object1,"even").start();///immediately start
        //here i need to define the thread name i want to this thread as a odd thread
        new Thread(object2,"odd").start();///immediately start
    }
}

Output

Now Let’s implement using java 8

import java.util.concurrent.*;
import java.util.stream.IntStream;

public class IdentifyEvenAndOddNumbersByThread {

    public static void main(String[] args) {
        ExecutorService service= Executors.newFixedThreadPool(2);
        IntStream.range(1,101)
                .forEach(
                number->{
                    CompletableFuture<Integer> evenFuture = CompletableFuture
                            .completedFuture(number)
                            .thenApplyAsync(e->{
                                if (e%2==0)
                                    System.out.println("Thread Name: "+Thread.currentThread().getName()+" : "+number);
                                return number;
                            },service);
                    evenFuture.join();
                    CompletableFuture<Integer> oddFuture = CompletableFuture
                            .completedFuture(number)
                            .thenApplyAsync(e->{
                                if (e%2!=0)
                                    System.out.println("Thread Name: "+Thread.currentThread().getName()+" : "+number);
                                return number;
                            },service);
                    oddFuture.join();
                }
        );
    }
}

Output

Thank you