Vorlesung 14 / Aufgabe 2

VL14/Aufgabe02/Aufgabe02.java

@@ -0,0 +1,27 @@
+package VL14.Aufgabe02;
+
+/**
+ * Vorlesung 14 / Aufgabe 2
+ *
+ * @author Sebastian Brosch
+ */
+public class Aufgabe02 {
+  public static void main(String[] args) {
+    final int NUMBER_OF_USERS = 5;
+    final int NUMBER_OF_PRINTERS = 2;
+
+    // create some users.
+    for (int u = 0; u < NUMBER_OF_USERS; u++) {
+      User user = new User();
+      Thread threadUser = new Thread(user);
+      threadUser.start();
+    }
+
+    // create some printers.
+    for (int p = 0; p < NUMBER_OF_PRINTERS; p++) {
+      Printer printer = new Printer();
+      Thread threadPrinter = new Thread(printer);
+      threadPrinter.start();
+    }
+  }
+}

VL14/Aufgabe02/Printer.java

@@ -0,0 +1,23 @@
+package VL14.Aufgabe02;
+
+/**
+ * Class which represents a printer.
+ *
+ * @author Sebastian Brosch
+ */
+public class Printer implements Runnable {
+  public void run() {
+    while (true) {
+      synchronized (PrinterQueue.queue) {
+        if (PrinterQueue.queue.size() > 0) {
+          System.out.println(PrinterQueue.queue.poll());
+        }
+      }
+
+      try {
+        Thread.sleep(500);
+      } catch (InterruptedException e) {
+      }
+    }
+  }
+}

VL14/Aufgabe02/PrinterQueue.java

@@ -0,0 +1,12 @@
+package VL14.Aufgabe02;
+
+import java.util.LinkedList;
+
+/**
+ * Class which represents a printer queue.
+ *
+ * @author Sebastian Brosch
+ */
+public class PrinterQueue {
+  static LinkedList<String> queue = new LinkedList<String>();
+}

VL14/Aufgabe02/User.java

@@ -0,0 +1,23 @@
+package VL14.Aufgabe02;
+
+/**
+ * Class which represents a user.
+ *
+ * @author Sebastian Brosch
+ */
+public class User implements Runnable {
+  private int number = 0;
+
+  public void run() {
+    while (true) {
+      synchronized (PrinterQueue.queue) {
+        PrinterQueue.queue.add(Thread.currentThread().getName() + ": " + this.number++);
+      }
+
+      try {
+        Thread.sleep(100);
+      } catch (InterruptedException e) {
+      }
+    }
+  }
+}