Thread.run() method in java - WebEncyclop Tutorials

Thread class contain a run() method which has empty implementation. So if we are using multithreading then we must override run() from Thread class.
If we override a Thread.run() in out class then the child thread is responsible to
execute this method.
If we don’t override a Thread.run() method in our class then it will call run() method from Thread class, which has no implementation. So no utput will get.

run() method won’t create a new Thread.

Overloading run() method

We can overload a Thread.run() method in our class. But Thread.start() always call no-argument run() method only. So if you want to call overloaded argument method, you have to call it explicitly.

class MyThread extends Thread
{
    public void run()
    {
         System.out.println("no-arg run method");   
    }  
    public void run(int i)
    {
         System.out.println("arg method");   
    } 
}
class Main
{
	public static void main(String[] args) {
	    MyThread  t=new MyThread();
	    t.start();   
	}
}

class MyThread extends Thread

{

public void run()

{

System.out.println("no-arg run method");

}

public void run(int i)

{

System.out.println("arg method");

}

class Main

{

public static void main(String[] args) {

MyThread t=new MyThread();

t.start();

}

Output:

no-arg run method

1	no-arg run method

Overriding run() method

We must override a run() method if we want to use multi-threading. If we don’t override a run(), then start() call Thread.run() which has empty implementation. so will not get any output.

class MyThread extends Thread
{
}
class Main
{
	public static void main(String[] args) {
	    MyThread  t=new MyThread();
	    t.start();  
	}
}