Java program for demonstrating multithreading

Aim

To write a program for demonstrating multithreading using Java.

Theory

A thread is a separate flow of execution in a program. All Java programs by default contain a single thread called the “Main thread”. A thread contains a set of statements like a method in Java. The difference between thread and a method is, unlike methods, threads can run simultaneously or in parallel with other threads.

Threads in Java are supported through Thread class and Runnable interface. A single thread is represented in a Java program as Thread class instance (object). To create a new thread in a Java program, we can either:

• Extend the Thread class or
• Implement the Runnable interface

Pseudo code / Steps

1. Create a class MyThread and either implement Runnable interface or extend Thread
2. Override the run
3. Create three threads (objects).
4. Every thread must display thread name followed by the text given in the next instruction.
5. The first thread should display the text “Welcome”, second thread should display “To”, and third thread should display “Java”.
6. Make each thread pause for 1 second (1000 milliseconds) after it prints the text.

Program

class MyThread extends Thread
{
	String message;
	MyThread(String m)
	{
		message = m;
	}
	public void run()
	{
		try
		{
			for(int i=0; i<3; i++)
			{
				System.out.println(this.getName() + "->" +
            		message);
				this.sleep(1000);
			}
		}
		catch(InterruptedException e)
		{}
	}
}
class ThreadDemo
{
	public static void main(String args[])
	{
		new MyThread("Welcome").start();
		new MyThread("To").start();
		new MyThread("Java").start();
	}
}

Input and Output:

Run1:

Thread-1->To
Thread-2->Java
Thread-0->Welcome
Thread-0->Welcome
Thread-1->To
Thread-2->Java
Thread-0->Welcome
Thread-1->To
Thread-2->Java

Run2:

Thread-0->Welcome
Thread-2->Java
Thread-1->To
Thread-2->Java
Thread-1->To
Thread-0->Welcome
Thread-0->Welcome
Thread-1->To
Thread-2->Java

Result

The concepts related to multithreading were understood and implemented successfully.

Suryateja Pericherla

Suryateja Pericherla, at present is a Research Scholar (full-time Ph.D.) in the Dept. of Computer Science & Systems Engineering at Andhra University, Visakhapatnam. Previously worked as an Associate Professor in the Dept. of CSE at Vishnu Institute of Technology, India.

He has 11+ years of teaching experience and is an individual researcher whose research interests are Cloud Computing, Internet of Things, Computer Security, Network Security and Blockchain.

He is a member of professional societies like IEEE, ACM, CSI and ISCA. He published several research papers which are indexed by SCIE, WoS, Scopus, Springer and others.