ThreadsDemo: Remade and including comments

Technology/ThreadsDemo/.classpath

@@ -1,6 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <classpath>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-17">
+		<attributes>
+			<attribute name="module" value="true"/>
+		</attributes>
+	</classpathentry>
 	<classpathentry kind="src" path="src"/>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
 	<classpathentry kind="output" path="bin"/>
 </classpath>

Technology/ThreadsDemo/.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding/<project>=UTF-8

Technology/ThreadsDemo/.settings/org.eclipse.jdt.core.prefs

@@ -0,0 +1,14 @@
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=17
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=17
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=warning
+org.eclipse.jdt.core.compiler.release=enabled
+org.eclipse.jdt.core.compiler.source=17

Technology/ThreadsDemo/src/ExtendingThreads.java

@@ -0,0 +1,14 @@
+
+public class ExtendingThreads extends Thread {
+
+	private String myString="";
+	
+	public ExtendingThreads( String initString ) {
+		myString = initString;
+	}
+	
+	public void run() {
+		System.out.println( "ExtendingThreads (" + myString + ")");
+	}
+
+}

Technology/ThreadsDemo/src/ImplementingRunnable.java

@@ -0,0 +1,22 @@
+
+public class ImplementingRunnable implements Runnable{
+
+	private String myString="";
+	
+	public ImplementingRunnable( String initString ) {
+		myString = initString;
+	}
+	
+	public void run() {
+		System.out.println( "ImplementingRunnable (" + myString + ")" );
+		// The next section of dead code shows how a thread may be set sleeping
+		if (false) {
+			try {
+				Thread.sleep(5000); // mS
+			} catch (InterruptedException e) {
+				e.printStackTrace();
+			}
+		}
+	}
+
+}

Technology/ThreadsDemo/src/Level1Interface.java

@@ -1,26 +0,0 @@
-//
-// Demo of thread starting a thread
-//
-
-public class Level1Interface  implements Runnable {
-
-	private String MyString;
-
-	public Level1Interface(String InitString) {
-		MyString = InitString;
-	}
-	
-	@Override
-	public void run() {
-		System.out.println(MyString + " Interface");
-		ThreadsExtend myThreadA = new ThreadsExtend( MyString + "A" );
-		myThreadA.start();
-		try {
-			myThreadA.join();
-		} catch (InterruptedException e) {
-			// TODO Auto-generated catch block
-			e.printStackTrace();
-		}
-		System.out.println(MyString + " Interface...Done");
-	}
-}

Technology/ThreadsDemo/src/ThreadStartingThread.java

@@ -0,0 +1,23 @@
+
+public class ThreadStartingThread implements Runnable{
+
+	private String myString="";
+	
+	public ThreadStartingThread( String initString ) {
+		myString = initString;
+	}
+	
+	@Override
+	public void run() {
+		System.out.println( "ThreadStartingThread (" + myString + ")" );
+		ExtendingThreads myThreadA = new ExtendingThreads( "ThreadStartingThread " + myString );
+		myThreadA.start();
+		try {
+			myThreadA.join();
+		} catch (InterruptedException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+	}
+
+}

Technology/ThreadsDemo/src/ThreadsDemo.java

@@ -1,23 +1,42 @@
+// Karsten Jeppesen, UCN
+// There are 3 ways to start threads.
+// This demo will show two of the options
+// - by extending the Thread class and overriding its run() method
+// - by implementing the Runnable interface
+//
 
 public class ThreadsDemo {
 
 	public static void main(String[] args) {
-		ThreadsExtend myThreadA = new ThreadsExtend("A");
+		System.out.println("Main");
-		ThreadsExtend myThreadB = new ThreadsExtend("B");
+		
-		ThreadsExtend myThreadC = new ThreadsExtend("C");
+		// Extending the Thread class will oc result in a thread
-		Runnable myRunnableD = new ThreadsInterface("D");
+		ExtendingThreads myThreadA = new ExtendingThreads("A");
-		Runnable myRunnableE = new ThreadsInterface("E");
+		ExtendingThreads myThreadB = new ExtendingThreads("B");
-		Runnable myRunnableF = new Level1Interface("F");
+		ExtendingThreads myThreadC = new ExtendingThreads("C");
+		
+		// implementing the runnable interface will require an additional call to threads
+		Runnable myRunnableD = new ImplementingRunnable("D");
+		Runnable myRunnableE = new ImplementingRunnable("E");
+		Runnable myRunnableF = new ImplementingRunnable("F");
+		Runnable myRunnableL = new ThreadStartingThread("L");
+		
+		// Here we inject the runnable into the thread class
+		Thread myThreadD = new Thread( myRunnableD );
+		Thread myThreadE = new Thread( myRunnableE );
+		Thread myThreadF = new Thread( myRunnableF );
+		Thread myThreadL = new Thread( myRunnableL );
+		
+		// Starting all threads. Note that sequence can not be guaranteed.
 		myThreadA.start();
 		myThreadB.start();
 		myThreadC.start();
-		Thread  myThreadD = new Thread( myRunnableD );
 		myThreadD.start();
-		Thread myThreadE = new Thread( myRunnableE );
 		myThreadE.start();
-		Thread myThreadF = new Thread( myRunnableF );
 		myThreadF.start();
+		myThreadL.start();
 		
+		// Waiting for all threads to complete is considered best practice
 		try {
 			myThreadA.join();
 			myThreadB.join();
@@ -25,10 +44,12 @@ public class ThreadsDemo {
 			myThreadD.join();
 			myThreadE.join();
 			myThreadF.join();
+			myThreadL.join();
 		} catch (InterruptedException e) {
-			// TODO Auto-generated catch block
 			e.printStackTrace();
 		}
-		System.out.println("Main Done...");
+		
+		System.out.println("Main... Done");
 	}
+
 }

Technology/ThreadsDemo/src/ThreadsExtend.java

@@ -1,20 +0,0 @@
-
-public class ThreadsExtend extends Thread {
-	private String MyString;
-	
-	public ThreadsExtend ( String InitString ) {
-		MyString = InitString;
-	}
-	
-	
-	public void run() {
-		try {
-			Thread.sleep(5000);
-		} catch (InterruptedException e) {
-			// TODO Auto-generated catch block
-			e.printStackTrace();
-		}
-		System.out.println(MyString + " running");
-	}
-
-}

Technology/ThreadsDemo/src/ThreadsInterface.java

@@ -1,15 +0,0 @@
-
-public class ThreadsInterface  implements Runnable {
-	
-	private String MyString;
-	
-	public ThreadsInterface(String InitString) {
-		MyString = InitString;
-	}
-	
-	@Override
-	public void run() {
-		System.out.println(MyString + " Interface");
-	}
-
-}