BAEL-382 BlocknigQueue producer consumer program

core-java/src/main/java/com/baeldung/concurrency/BlockingQueueUsage.java

@@ -0,0 +1,81 @@
+package com.baeldung.concurrency;
+
+
+import java.util.Random;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+
+public class BlockingQueueUsage {
+    public static void main(String[] args) {
+        int BOUND = 10;
+        int N_PRODUCERS = 4;
+        int N_CONSUMERS = Runtime.getRuntime().availableProcessors();
+
+
+        BlockingQueue<Integer> queue = new LinkedBlockingQueue<>(BOUND);
+
+        for (int i = 0; i < N_PRODUCERS; i++) {
+            System.out.println("new Producer");
+            new Thread(new NumbersProducer(queue)).start();
+        }
+
+        for (int j = 0; j < N_CONSUMERS; j++) {
+            System.out.println("new Consumer");
+            new Thread(new NumbersConsumer(queue)).start();
+        }
+    }
+
+
+    //producer
+    static class NumbersProducer implements Runnable {
+        private final Random random = new Random();
+        private final BlockingQueue<Integer> numbersQueue;
+
+
+        public NumbersProducer(BlockingQueue<Integer> numbersQueue) {
+            this.numbersQueue = numbersQueue;
+        }
+
+
+        public void run() {
+            try {
+                generateNumbers();
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+        }
+
+        private void generateNumbers() throws InterruptedException {
+            for (int i = 0; i < 100; i++) {
+                numbersQueue.put(random.nextInt(100));
+            }
+        }
+    }
+
+    //consumer
+    static class NumbersConsumer implements Runnable {
+        private final BlockingQueue<Integer> queue;
+
+        public NumbersConsumer(BlockingQueue<Integer> queue) {
+            this.queue = queue;
+        }
+
+        public void run() {
+            try {
+                while (true) {
+                    Integer number = queue.take();
+                    int result = fibonacci(number);
+                    System.out.println("fibonacci result: " + result);
+
+                }
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+        }
+
+        public int fibonacci(Integer number) {
+            if (number <= 1) return number;
+            else return fibonacci(number - 1) + fibonacci(number - 2);
+        }
+    }
+}