Connecting threads with Java

java.lang.ThreadThe class provides a methodjoin(), which can be used in its overloaded version to achieve the following purposes.

• join() -The current thread calls this method on the second thread, causing the current thread to block until the second thread terminates.

• join(long millisec) -The current thread calls this method on the second thread, causing the current thread to block until the second thread terminates or the specified milliseconds.

• join(long millisec, int nanos) -The current thread calls this method on the second thread, causing the current thread to block until the second thread terminates or the specified milliseconds+up to nanoseconds.

Please refer to the following example to demonstrate this concept.

Example

class CustomThread implements Runnable {
　　　public void run() {
　　　　　　System.out.println(Thread.currentThread().getName()　+　" started.");
　　　　　　try {
　　　　　　　　　Thread.sleep(500);
　　　　　　} catch (InterruptedException e) {
　　　　　　　　　System.out.println(Thread.currentThread().getName()　+　" interrupted.");
　　　　　　}
　　　　　　System.out.println(Thread.currentThread().getName()　+　" exited.");
　　　}
}
public class Tester {
　　　public static void main(String args[]) throws InterruptedException {
　　　　　　Thread t1　= new Thread(new CustomThread(), "Thread-1");
　　　　　　t1.start();
　　　　　　//The main thread class is in t1the connection on
　　　　　　//Once t1completed, then only t2can start
　　　　　　t1.join();
　　　　　　Thread t2　= new Thread(new CustomThread(), "Thread-2");
　　　　　　t2.start();
　　　　　　//The main thread class is in t2the connection
　　　　　　//Once t2completed, then only t3can start
　　　　　　t2.join();
　　　　　　Thread t3　= new Thread(new CustomThread(), "Thread-3");
　　　　　　t3.start();
　　　}
}

Output Result

Thread-1　started.
Thread-1　exited.
Thread-2　started.
Thread-2　exited.
Thread-3　started.
Thread-3　exited.