Java join() method

 

Java join() method

When the join() method is invoked, the current thread stops its execution and the thread goes into the wait state. The current thread remains in the wait state until the thread on which the join() method is invoked has achieved its dead state. If interruption of the thread occurs, then it throws the InterruptedException.

Example 01:

package com.java.Multi_threading;

// A Java program for understanding   

// the joining of threads  

  

// import statement  

import java.io.*;  

  

// The ThreadJoin class is the child class of the class Thread  

class ThreadJoin extends Thread  

{  

// overriding the run method  

public void run()  

{  

for (int j = 0; j < 2; j++)  

{  

try  

{  

// sleeping the thread for 300 milli seconds  

Thread.sleep(300);  

System.out.println("The current thread name is: " + Thread.currentThread().getName());  

}  

// catch block for catching the raised exception  

catch(Exception e)  

{  

System.out.println("The exception has been caught: " + e);  

}  

System.out.println( j );  

}  

}  

}  

  

public class ThreadJoinExample  

{  

// main method  

public static void main (String argvs[])  

{  

  

// creating 3 threads  

ThreadJoin th1 = new ThreadJoin();  

ThreadJoin th2 = new ThreadJoin();  

ThreadJoin th3 = new ThreadJoin();  

  

// thread th1 starts  

th1.start();  

  

// starting the second thread after when  

// the first thread th1 has ended or died.  

try  

{  

System.out.println("The current thread name is: "+ Thread.currentThread().getName());  

  

// invoking the join() method  

th1.join();  

}  

  

// catch block for catching the raised exception  

catch(Exception e)  

{  

System.out.println("The exception has been caught " + e);  

}  

  

// thread th2 starts  

th2.start();  

  

// starting the th3 thread after when the thread th2 has ended or died.  

try  

{  

System.out.println("The current thread name is: " + Thread.currentThread().getName());  

th2.join();  

}  

  

// catch block for catching the raised exception  

catch(Exception e)  

{  

System.out.println("The exception has been caught " + e);  

}  

  

// thread th3 starts  

th3.start();  

}  

}