Introduction

• Every thread in a Java program has a unique name.
• Whenever we create a new thread, the JVM automatically assigns a default name such as Thread-0, Thread-1, Thread-2 and so on.
• Use :-
  • Identify threads by name for logging and debugging purposes.
  • Give meaningful names to threads in multi-threaded applications.
  • Track thread execution in large concurrent programs.
• To work with thread names, Java provides two important methods in the Thread class:
  1. public final String getName()
     • Used to retrieve the current name of a thread.
  2. public final void setName(String name)
     • Used to assign or change the name of a thread.
• Program :-

  class MyThread extends Thread
  {
      @Override
      public void run()
      {
          System.out.println("Thread running: " + getName());
  
          // Change the thread name
          setName("Updated-Thread");
          System.out.println("Thread renamed to: " + getName());
      }
  }
  
  public class ThreadNameDemo
  {
      public static void main(String[] args)
      {
          MyThread t1 = new MyThread();
          t1.setName("Initial-Thread");
  
          System.out.println("Before start: " + t1.getName());
  
          t1.start();
  
          // Main thread
          System.out.println("Main thread: " + Thread.currentThread().getName());
      }
  }

  Output (sample):

  Before start: Initial-Thread
  Main thread: main
  Thread running: Initial-Thread
  Thread renamed to: Updated-Thread

• Other key points :-
  • Both methods are final, cannot be overridden.
  • Useful for logging and debugging multi-threaded applications.
  • Thread names can be set either via setName() or constructor Thread(String name).
  • Default thread names are like Thread-0, Thread-1, etc., if not set explicitly.