Java Supports Multi-Threading Programming

Computer History Notes - Herong's Tutorial Notes

∟1995 - Java Language Developed by Sun Microsystems

∟Java Supports Multi-Threading Programming

This section provides a quick demonstration of the multi-threading programming support in Java language.

Java supports multithreading (concurrency) programming. Multiple threads of executions can be initiated and synchronized in a single Java application. All threads in a single application share the same set of resources.

What Is Multi-Threading Programming? Multi-treading programming is the ability of writing a single application that can execute multiple sections of codes simultaneously.

Here is a sample Java program showing you two threads are executed simultaneously:

/* ThreadDemo.java
 * Copyright (c) 2003 HerongYang.com. All Rights Reserved.
 */
import java.util.*;
class ThreadDemo {
   public static void main(String[] args) {
      Thread wordGenerator = new WordThread();
      wordGenerator.start();

      Thread numberGenerator = new NumberThread();
      numberGenerator.start();
   }

   static class WordThread extends Thread {
      public void run() {
         while (true) {
            Random generator = new Random();
            int size = 3 + generator.nextInt(5);
            String value = "";
            for (int i=0; i<size; i++) {
              int d = generator.nextInt(26) + 'a';
              value += (char) d;
            }
            System.out.println("Word Thread: "+value);
            try {
               sleep(1000);
            } catch (InterruptedException e) {
            }
         }
      }
   }

   static class NumberThread extends Thread {
      public void run() {
         while (true) {
            Random generator = new Random();
            int size = 3 + generator.nextInt(5);
            long value = 0;
            for (int i=0; i<size; i++) {
              int d = generator.nextInt(10);
              value = value*10 + d;
            }
            System.out.println("Number Thread: "+value);
            try {
               sleep(1000);
            } catch (InterruptedException e) {
            }
         }
      }
   }
}

If you run this Java sample program, you will get output similar to this:

java ThreadDemo

Word Thread: cjsdlen
Number Thread: 64845
Word Thread: ldyb
Number Thread: 92076
Word Thread: gari
Number Thread: 114
Word Thread: mjjieu
Number Thread: 2876
Word Thread: xfsrq
Number Thread: 66858
Word Thread: cfs
Number Thread: 35258
Word Thread: urpfi
Number Thread: 4120008