Java Thread Join using join() method

• Java Join method join the next thread at the end of the current thread
• After current thread stops execution then next thread executes.

Syntax:

public void join() throws InterruptedException
public void join(long miliseconds) throws InterruptedException

class JoinDemo extends Thread{
 public void run(){
  for(int i=1;i<=5;i++){
   try{
    Thread.sleep(500);
   }catch(Exception e){
     System.out.println(e);
   }
   System.out.println("Dinesh on Java "+i);
   }
  }
public static void main(String args[]){
 JoinDemo t1 = new JoinDemo();
 JoinDemo t2 = new JoinDemo();
 JoinDemo t3 = new JoinDemo();
 t1.start();
 try{
  t1.join();
 }catch(Exception e){
   System.out.println(e);
 }

 t2.start();
 t3.start();
 }
}

As you can see in the above example,when t1 completes its task then t2 and t3 starts executing.
output:

//Example of join(long miliseconds) method
class JoinDemo extends Thread{
 public void run(){
  for(int i=1;i<=5;i++){
   try{
    Thread.sleep(500);
   }catch(Exception e){
     System.out.println(e);
   }
   System.out.println("Dinesh on Java "+i);
   }
  }
public static void main(String args[]){
 JoinDemo t1 = new JoinDemo();
 JoinDemo t2 = new JoinDemo();
 JoinDemo t3 = new JoinDemo();
 t1.start();
 try{
  t1.join(1500);
 }catch(Exception e){
   System.out.println(e);
 }

 t2.start();
 t3.start();
 }
}

In the above example,when t1 is completes its task for 1500 milliseconds(3 times) then t2 and t3 starts executing.
output:

Using getName(), setName(String) and getId() method:

public String getName()//is used to return the name of a thread.
public void setName(String name)//is used to change the name of a thread.
public long getId()//is used to return the id of a thread.

class JoinDemo extends Thread{
 public void run(){
  for(int i=1;i<=5;i++){
   try{
    Thread.sleep(500);
   }catch(Exception e){
     System.out.println(e);
   }
   System.out.println("Running thread is "+Thread.currentThread().getName()+" : "+i);
   }
  }
public static void main(String args[]){
 JoinDemo t1 = new JoinDemo();
 JoinDemo t2 = new JoinDemo();
 JoinDemo t3 = new JoinDemo();
 t1.setName("Dinesh on Java");
 System.out.println("id of t1:"+t1.getId());
 System.out.println("id of t2:"+t2.getId());
 System.out.println("id of t3:"+t3.getId());
 t1.start();
 try{
  t1.join(1500);
 }catch(Exception e){
   System.out.println(e);
 }

 t2.start();
 t3.start();
 }
}

The currentThread() method:
The currentThread() method returns a reference to the currently executing thread object.
output: