added ex Q1

src/exercises/ex_q1/Pizza.java

@@ -0,0 +1,13 @@
+package exercises.ex_q1;
+
+public class Pizza {
+    public void prepare() {
+        System.out.println("Preparing pizza.");
+    }
+    public void bake() {
+        System.out.println("Baking pizza.");
+    }
+    public void cut() {
+        System.out.println("Cutting pizza.");
+    }
+}

src/exercises/ex_q1/Pizzaiolo.java

@@ -0,0 +1,34 @@
+package exercises.ex_q1;
+
+import java.util.concurrent.Callable;
+
+public class Pizzaiolo implements Callable<Pizza> {
+    private final String name;
+
+    public Pizzaiolo(String name) {
+        this.name = name;
+    }
+
+    public void serve(Pizza pizza) {
+        System.out.println(name + "'s pizza is ready: pizza " + pizza.hashCode());
+    }
+
+    public Pizza makePizza() throws InterruptedException {
+        Pizza pizza = new Pizza();
+        pizza.prepare();
+        Thread.sleep(200);
+        pizza.bake();
+        Thread.sleep(300);
+        pizza.cut();
+        Thread.sleep(100);
+        return pizza;
+    }
+
+    @Override
+    public Pizza call() throws Exception {
+        System.out.println("Thread " + name + " started by the executor");
+        Pizza pizza = makePizza();
+        System.out.println("Thread " + name + " pizza finished");
+        return pizza;
+    }
+}

src/exercises/ex_q1/Pizzeria.java

@@ -0,0 +1,26 @@
+package exercises.ex_q1;
+
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+
+public class Pizzeria {
+    public static void main(String[] args) throws ExecutionException, InterruptedException {
+        ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
+        Pizzaiolo marco = new Pizzaiolo("Marco");
+        Pizzaiolo antonio = new Pizzaiolo("Antonio");
+
+        Future<Pizza> future1 = executor.submit(marco);
+        Future<Pizza> future2 = executor.submit(antonio);
+        Future<Pizza> future3 = executor.submit(marco);
+        Future<Pizza> future4 = executor.submit(antonio);
+
+        marco.serve(future1.get());
+        antonio.serve(future2.get());
+        marco.serve(future3.get());
+        antonio.serve(future4.get());
+
+        executor.shutdown();
+    }
+}