In a multi-threading application if lots of thread have been spawned and you want to identify those thread then you can get the thread's name or thread's ID. This post shows how to set and get thread's name in Java and how to get thread ID in Java.
Setting Thread's name in Java
If you want to set a thread’s name in order to identify a thread that can be done in 2 ways.
- Using the constructor of the Thread class
- Using the setName() method
Thread ID in Java
Another way to uniquely identify a thread is to get thread's ID in Java. Thread class has getId() method which returns the thread’s ID.
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.
Setting thread name using constructor of the Thread class
Thread class has a constructor Thread(Runnable target, String name) which takes two arguments, a runnable object and a String which sets the thread’s name.
class MyThread implements Runnable{ @Override public void run() { // Getting thread's name System.out.println("Thread Name- " +Thread.currentThread().getName()); // Getting thread's ID System.out.println("Thread ID- " +Thread.currentThread().getId() + " For " + Thread.currentThread().getName()); try { Thread.sleep(10); } catch (InterruptedException e) { e.printStackTrace(); } System.out.println("Finished with thread"); } } public class ThreadName { public static void main(String[] args) { // Creating 3 threads Thread t1 = new Thread(new MyThread(), "Thread-1"); Thread t2 = new Thread(new MyThread(), "Thread-2"); Thread t3 = new Thread(new MyThread(), "Thread-3"); // Starting threads t1.start(); t2.start(); t3.start(); } }
Output
Thread Name- Thread-2 Thread Name- Thread-3 Thread Name- Thread-1 Thread ID- 12 For Thread-3 Thread ID- 11 For Thread-2 Thread ID- 10 For Thread-1 Finished with thread Finished with thread Finished with thread
Here it can be seen that thread’s name is set in the constructor and thread’s ID is also retrieved.
Setting thread name using setName() method Java example
class MyThread implements Runnable{ @Override public void run() { // Getting thread's name System.out.println("Thread Name- " +Thread.currentThread().getName()); // Getting thread's ID System.out.println("Thread ID- " +Thread.currentThread().getId() + " For " + Thread.currentThread().getName()); try { Thread.sleep(10); } catch (InterruptedException e) { e.printStackTrace(); } System.out.println("Finished with thread"); } } public class ThreadName { public static void main(String[] args) { // Creating 3 threads Thread t1 = new Thread(new MyThread()); t1.setName("Thread-1"); Thread t2 = new Thread(new MyThread()); t2.setName("Thread-2"); Thread t3 = new Thread(new MyThread()); t3.setName("Thread-3"); // Starting threads t1.start(); t2.start(); t3.start(); } }
Output
Thread Name- Thread-1 Thread Name- Thread-3 Thread Name- Thread-2 Thread ID- 12 For Thread-3 Thread ID- 10 For Thread-1 Thread ID- 11 For Thread-2 Finished with thread Finished with thread Finished with thread
That's all for this topic Setting And Getting Thread Name And Thread ID in Java. If you have any doubt or any suggestions to make please drop a comment. Thanks!
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