Create a thread by implementing Runnable interface

We can create thread in the following two ways .

1) By extending Thread class
2) By implementing Runnable interface

In this tutorial we are going to learn how to create thread by implementing Runnable interface .

Creating thread by implementing Runnable interface :

We can create thread by implementing Runnable interface also . Runnable interface present in java.lang package and contains run() method alone. If we implement Runnable interface , it is mandatory to override run() method in our class .

package com.java.jigi;

class RunnableImpl implements Runnable {
    public void run() {
        for (int i = 0; i < 10; i++) {
            System.out.println(i);
        }
    }
}
public class RunnableExample  {
    public static void main(String as[])
    {
        Thread t = new Thread(new RunnableImpl());
        t.start();
    }
}

See the above exmaple, when you call start() method then thread executes run() method and prints 0 1 2 3 ..9. Never override start() method in your class . If you override start() , then your start() will be executed rather than run() method . If you call run() method rather than start(), It will be executed as normal method calling .

Between above two approaches “implementing runnable interface” is best approach. If we extend Thread class, we can’t extend any othere class.