What is Thread.isDaemon() function in Java?

Overview

isDaemon() is used to check whether a thread is a daemon thread.

Note: isDaemon() is a thread class method.

Syntax

final boolean isDaemon()

Parameter

This method does not take any argument value.

Return value

• booleanValue: It returns True, if the thread is daemon. Otherwise, it returns False.

Code

The code snippet below elaborates the use of isDaemon() method in a program:

Explanation

Edpresso.java

• Line 6: We create SampleThread instance sample because it implements a Runnable interface.
• Line 7: We create a Thread instance thread1 with sample and thread “Thread 1”.
• Line 8: We create a second Thread instance thread2 with sample and thread “Thread 2” to the constructor.
• Line 10: We mark Thread 1 as daemon thread i.e. thread1.setDaemon(true).
• Line 11: thread2.Start() begins execution of thread2 by calling JVM to call run() method from Runnable interface.
• Line 12: thread1.Start() begins execution of thread1 by calling JVM to call run() method from Runnable interface.

SampleThread.java

• Line 5: We check if the current thread is marked as daemon thread or not.
• Line 6: If the current thread is daemon, it shows a proper message. i.e.,"Thread 1 is a daemon thread".
• Line 9: If the current thread is not daemon, it shows a proper message. i.e.,"Thread 2 is a user thread".