Java sender receiver using multithreading

Data.java

public class Data {
    private String packet;

    // True: receiver waits
    // False: sender waits
    private boolean transfer = true;

    public synchronized String receive() {
        while (transfer) {
            try {
                wait();
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
                System.err.println("Thread Interrupted");
            }
        }

        transfer = true;
        notifyAll();
        return packet;
    }

    public synchronized void send(String packet) {
        while (!transfer) {
            try {
                wait();
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
                System.err.println("Thread Interrupted");
            }
        }

        this.packet = packet;
        transfer = false;
        notifyAll();
    }
}

Main.java

public class Main {
    public static void main(String[] args) {
        Data data = new Data();
        Thread sender = new Thread(new Sender(data));
        Thread receiver = new Thread(new Receiver(data));

        sender.start();
        receiver.start();
    }
}

Receiver.java

public class Receiver implements Runnable {
    private final Data load;

    public Receiver(Data load) {
        this.load = load;
    }

    public void run() {
        // Keep receiving messages until "End" is received
        while (true) {
            String receivedMessage = load.receive();

            if ("End".equals(receivedMessage)) {
                break;
            }

            System.out.println(receivedMessage);
        }
    }
}

Sender.java

public class Sender implements Runnable {
    private final Data data;

    public Sender(Data data) {
        this.data = data;
    }

    public void run() {
        List<String> packets = List.of(
                "First packet",
                "Second packet",
                "Third packet",
                "Fourth packet",
                "End");

        packets.forEach(data::send);
    }
}