Add OOP/Java/Assignments/FISAC/Q10.java

OOP/Java/Assignments/FISAC/Q10.java

@@ -0,0 +1,85 @@
+import java.util.concurrent.locks.*;
+
+class FullException extends Exception {
+    FullException(String msg) { super(msg); }
+}
+
+class Box<T> {
+    private T[] items = (T[]) new Object[3];
+    private int count = 0;
+    private Lock lock = new ReentrantLock();
+    private Condition notFull = lock.newCondition(), notEmpty = lock.newCondition();
+
+    void add(T item) throws FullException, InterruptedException {
+        lock.lock();
+        try {
+            if (count == items.length) throw new FullException("Box is full");
+            while (count == items.length) notFull.await();
+            items[count++] = item;
+            notEmpty.signal();
+        } finally {
+            lock.unlock();
+        }
+    }
+
+    T retrieve() throws InterruptedException {
+        lock.lock();
+        try {
+            while (count == 0) notEmpty.await();
+            T item = items[--count];
+            notFull.signal();
+            return item;
+        } finally {
+            lock.unlock();
+        }
+    }
+
+    boolean isEmpty() {
+        return count == 0;
+    }
+
+    void clear() {
+        count = 0;
+    }
+}
+
+class Student {
+    String name;
+    Student(String name) { this.name = name; }
+    public String toString() { return name; }
+}
+
+public class Main {
+    public static void main(String[] args) throws Exception {
+        Box<Integer> intBox = new Box<>();
+        Box<String> strBox = new Box<>();
+        Box<Student> studentBox = new Box<>();
+
+        Thread t1 = new Thread(() -> {
+            try {
+                intBox.add(1);
+                intBox.add(2);
+                intBox.add(3);
+                System.out.println(intBox.retrieve());
+            } catch (Exception e) { e.printStackTrace(); }
+        });
+
+        Thread t2 = new Thread(() -> {
+            try {
+                strBox.add("Hello");
+                System.out.println(strBox.retrieve());
+            } catch (Exception e) { e.printStackTrace(); }
+        });
+
+        Thread t3 = new Thread(() -> {
+            try {
+                studentBox.add(new Student("Alice"));
+                System.out.println(studentBox.retrieve());
+            } catch (Exception e) { e.printStackTrace(); }
+        });
+
+        t1.start();
+        t2.start();
+        t3.start();
+    }
+}