Thread isAlive() and join() Methods in Java

There are two ways to determine whether a thread has finished or not.

isAlive()
join()

isAlive(): isAlive() method is used to check whether a thread is in the running or not .

In a another word, this method determines thread is live or dead.

isAlive( )method returns true if the thread is still running otherwise it returns false.

join(): This method wait for the specified thread to terminate.

import java.lang.*;
public class Demo implements Runnable {
    public void run() {
        Thread t = Thread.currentThread(); // tests if this thread is alive	
        System.out.println("thread is live = " + t.isAlive()); // tests if this thread is alive	
    }
    public static void main(String args[]) throws Exception {
        Thread t = new Thread(new Demo());
        t.start(); // this will call run() function
        t.join(); // waits for this thread to die		
        System.out.println("thread is live = " + t.isAlive()); // tests if this thread is alive	
    }
}

import java.lang.*;

public class Demo implements Runnable {

public void run() {

Thread t = Thread.currentThread(); // tests if this thread is alive

System.out.println("thread is live = " + t.isAlive()); // tests if this thread is alive

}

public static void main(String args[]) throws Exception {

Thread t = new Thread(new Demo());

t.start(); // this will call run() function

t.join(); // waits for this thread to die

System.out.println("thread is live = " + t.isAlive()); // tests if this thread is alive

}

Result

thread is live = true
thread is live = false

1 2	thread is live = true thread is live = false