ThreadsDemo: Added multilevel threads

ThreadsDemo/src/Level1Interface.java

@@ -0,0 +1,26 @@
+//
+// 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");
+	}
+}

ThreadsDemo/src/ThreadsDemo.java

@@ -7,6 +7,7 @@ public class ThreadsDemo {
 		ThreadsExtend myThreadC = new ThreadsExtend("C");
 		Runnable myRunnableD = new ThreadsInterface("D");
 		Runnable myRunnableE = new ThreadsInterface("E");
+		Runnable myRunnableF = new Level1Interface("F");
 		myThreadA.start();
 		myThreadB.start();
 		myThreadC.start();
@@ -14,14 +15,20 @@ public class ThreadsDemo {
 		myThreadD.start();
 		Thread myThreadE = new Thread( myRunnableE );
 		myThreadE.start();
+		Thread myThreadF = new Thread( myRunnableF );
+		myThreadF.start();
 		
 		try {
 			myThreadA.join();
 			myThreadB.join();
 			myThreadC.join();
+			myThreadD.join();
+			myThreadE.join();
+			myThreadF.join();
 		} catch (InterruptedException e) {
 			// TODO Auto-generated catch block
 			e.printStackTrace();
 		}
+		System.out.println("Main Done...");
 	}
 }