Open In App
Related Articles

Thread isAlive() Method in Java With Examples

Improve Article
Save Article
Like Article

Thread class in java provides numerous methods that are very essential in order to understand the working of threads as the thread stages are triggered by them. Java multi-threading provides two ways to find with the help of isAlive() and join() method.
One thread gets to know when another thread has ended. Let us do depict stages of the lifecycle of the thread via the below image which helps us to connect dots to understand these methods’ workings.

Now let us do discuss isAlive() method of Thread class to a deeper depth. Basically, this method works internally very closely in parallel to the lifecycle stages of a thread. It tests if this thread is alive. A thread is alive if it has been started and has not yet died. There is a transitional period from when a thread is running to when a thread is not running. 
After the run() method returns, there is a short period of time before the thread stops. If we want to know if the start method of the thread class has been called or if the thread has been terminated, we must use the isAlive() method. This method is used to find out if a thread has actually been started and has yet not terminated. 


final boolean isAlive()

Return Value:  Boolean value returns 

Note: While returning this function returns true if the thread upon which it is called is still running. It returns false otherwise.



// Java program to Illustrate isAlive() Method
// of Thread class
// Main class extending Thread class
public class oneThread extends Thread {
    // Method 1
    // run() method for thread
    public void run()
        // Print statement
        System.out.println("geeks ");
        // Try block to check for exceptions
        try {
            // making thread to sleep for 300 nano-seconds
           // using sleep() method
        // Catch block to handle InterruptedException
        catch (InterruptedException ie) {
        // Display message when exception occurred
        System.out.println("forgeeks ");
    // Method 2
    // Main driver method
    public static void main(String[] args)
        // Creating threads using above class as
        // it is extending Thread class
        oneThread c1 = new oneThread();
        oneThread c2 = new oneThread();
        // Starting threads
        // Checking whether thread is alive or not
        // Returning boolean true if alive else false



If you like GeeksforGeeks and would like to contribute, you can also write an article using or mail your article to See your article appearing on the GeeksforGeeks main page and help other Geeks. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

Whether you're preparing for your first job interview or aiming to upskill in this ever-evolving tech landscape, GeeksforGeeks Courses are your key to success. We provide top-quality content at affordable prices, all geared towards accelerating your growth in a time-bound manner. Join the millions we've already empowered, and we're here to do the same for you. Don't miss out - check it out now!

Last Updated : 09 May, 2022
Like Article
Save Article
Similar Reads
Complete Tutorials