Differencebetween Thread.Start() and Thread.Run()

What's the difference between Thread start() and Runnable run()

First example: No multiple threads. Both execute in single (existing) thread. No thread creation.

R1 r1 = new R1();
R2 r2 = new R2();

r1 and r2 are just two different objects of classes that implement the Runnable interface and thus implement the run() method. When you call r1.run() you are executing it in the current thread.

Second example: Two separate threads.

Thread t1 = new Thread(r1);
Thread t2 = new Thread(r2);

t1 and t2 are objects of the class Thread. When you call t1.start(), it starts a new thread and calls the run() method of r1 internally to execute it within that new thread.

What is the difference between Thread.start() and Thread.run()?

No, you can't. Calling run will execute run() method in the same thread, without starting new thread.

Java multithreading difference between run() and start()

It's amazing how many people can answer a question by repeating what the OP already wrote without actually answering the question.

The solution is that you are first asking for the name of the running thread, but the second time you ask for the name of the thread insurance where the code or executed. If you change the later to Thread.currentThread instead of this you will get the expected answer.

Difference between running and starting a thread

Thread.run() does not spawn a new thread whereas Thread.start() does, i.e Thread.run actually runs on the same thread as that of the caller whereas Thread.start() creates a new thread on which the task is run.

What will happen use run() instead of start() of a thread?

Calling run directly on a Thread object defeats the point of having the Thread in the first place.

If you call run, then run will execute in the current Thread, as a normal method. You must call the startmethod on the Thread to have run execute in a different Thread.

Causes this thread to begin execution; the Java Virtual Machine calls the run method of this thread.

When would you call java's thread.run() instead of thread.start()?

You might want to call run() in a particular unit test that is concerned strictly with functionality and not with concurrency.