BlockingQueue

BlockingQueue is a thread-safe queue that supports operations that wait for the queue

to become non-empty when retrieving an element and wait for space to become available

in the queue when storing an element.

class Producer implements Runnable {
private BlockingQueue<String> queue;

public Producer(BlockingQueue<String> queue) {
this.queue = queue;
    }

@Override
public void run() {
String[] messages = {
"First message",
"Second message",
"Third message",
"Fourth message",
"End"
};

try {
for (String message : messages) {
queue.put(message);
System.out.println("Produced: " + message);
Thread.sleep(500);
            }
        } catch (InterruptedException e) {
Thread.currentThread().interrupt();
System.out.println("Thread interrupted");
        }
    }
}

class Consumer implements Runnable {
private BlockingQueue<String> queue;

public Consumer(BlockingQueue<String> queue) {
this.queue = queue;
    }

@Override
public void run() {
try {
String message;
while (!"End".equals(message = queue.take())) {
System.out.println("Consumed: " + message);
Thread.sleep(1000);
            }
        } catch (InterruptedException e) {
Thread.currentThread().interrupt();
System.out.println("Thread interrupted");
        }
    }
}

public class BlockingQueue2 {
public static void main(String[] args) {
BlockingQueue<String> queue = new ArrayBlockingQueue<>(10);
Thread producer = new Thread(new Producer(queue));
Thread consumer = new Thread(new Consumer(queue));

producer.start();
consumer.start();
    }
}

C:\java\jdk22\bin\java.exe

Produced: First message

Consumed: First message

Produced: Second message

Consumed: Second message

Produced: Third message

Produced: Fourth message

Consumed: Third message

Produced: End

Consumed: Fourth message