Create runnable task using functional interface – java8 lambda stream (example)

Leave a Comment / By Yogesh / January 29, 2016

1. Functional Interface java 8:

The interface having one abstract method is called the functional interface. E.g. Comparator, Runnable interface. The runnable interface will look like as follows

@FunctionalInterface
public interface Runnable {
 public abstract void run();
}

We have discussed about the Create threads using runnable interface. In current post, we will see how can we create Runnable task using Java 8 lambda.

2. Create thread using anonymous class:

//Tradition approach 1
Thread traditionalThread = new Thread(new Runnable() {          
    @Override
    public void run() {
        System.out.println("Runnable Traditional approach 1");      
    }
});

3. Create task in java using Runnable functional interface:

We will simply omit the anonymous class and we will have much cleaner code as

Runnable myTask = () -> System.out.println("Runnable using Java 8 lambda approach");

4. Program – create task using runnable functional interface

package org.learn;
 
class MyTask implements Runnable {
    public void run() {
        System.out.println("Runnable Traditional approach 2");
    }
}
 
public class RunnableUsingJava8 {
 
    public static void main(String[] args) throws InterruptedException {
        // Tradition approach 1
        Thread traditionalThread = new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println("Runnable Traditional approach 1");
            }
        });
        traditionalThread.start();
 
        // Tradition approach 2
        Thread traditionalThread2 = new Thread(new MyTask());
        traditionalThread2.start();
 
        // Runnable using java 8 lambda
        Runnable myTask = () -> System.out.println("Runnable using Java 8 lambda approach");
        Thread thread = new Thread(myTask);
        thread.start();
    }
}

5. Output – Task using runnable functional interface (java 8)

Runnable Traditional approach 1
Runnable Traditional approach 2
Runnable using Java 8 lambda approach