Java.lang.Thread.getId() Method

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Description

The java.lang.Thread.getId() method returns the identifier of this Thread. The thread ID is a positive long number generated when this thread was created.

The thread ID is unique and remains unchanged during its lifetime. When a thread is terminated, this thread ID may be reused.

Declaration

Following is the declaration for java.lang.Thread.getId() method

public long getId()

Parameters

NA

Return Value

This method returns this thread's ID.

Exception

NA

Example

The following example shows the usage of java.lang.Thread.getId() method.

package com.tutorialspoint;

import java.lang.*;

public class ThreadDemo implements Runnable {

   Thread t;
   ThreadDemo() {

      // thread created
      t = new Thread(this, "Admin Thread");
      
      // set thread priority
      t.setPriority(1);
      
      // prints thread created
      System.out.println("thread  = " + t);
      
      // this will call run() function
      t.start();
   }

   public void run() {
      // returns the identifier of this Thread.
      System.out.println("Name = " + t.getName());
      System.out.print("Id = " + t.getId());
   }

   public static void main(String args[]) {
      new ThreadDemo();
   }
}

Let us compile and run the above program, this will produce the following result −

thread  = Thread[Admin Thread,1,main]
Name = Admin Thread
Id = 21