java - エクスチェンジャーを使用して交換が行われるスレッドのタイプを指定する方法は?

Question

私は2つのRunnableクラスReaderを持っていWriterます.

import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.util.concurrent.Exchanger;

public class Reader implements Runnable {
    private static final int THRESHHOLD = 1000;
    private final int START, STOP;
    private Exchanger<ByteBuffer> exch;
    private RandomAccessFile file;
    private ByteBuffer buffer;

    public Reader(Exchanger<ByteBuffer> ex, RandomAccessFile f, int start, int stop) {
        START = start;
        STOP = stop;
        exch = ex;
        file = f;
        buffer = ByteBuffer.allocate(THRESHHOLD);
        buffer.mark();
    }

    @Override
    public void run() {
        for(int i = START; i < STOP; i++)
            try {
                buffer.put((byte)file.read());
            } catch(IOException e) {
                e.printStackTrace();
            }
        try {
            exch.exchange(buffer);
        } catch(InterruptedException e) {
            e.printStackTrace();
        }
    }
}



import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.util.concurrent.Exchanger;
import java.util.concurrent.locks.ReentrantLock;

public class Writer implements Runnable {
    private static final int THRESHHOLD = 1000;
    private final int START, STOP;
    private ReentrantLock lock;
    private Exchanger<ByteBuffer> exch;
    private RandomAccessFile file;
    private ByteBuffer buffer;

    public Writer(Exchanger<ByteBuffer> e, ReentrantLock l, RandomAccessFile f, int start, int stop) {
        lock = l;
        START = start;
        STOP = stop;
        exch = e;
        file = f;
    }

    @Override
    public void run() {
        try {
            buffer = exch.exchange(ByteBuffer.allocate(THRESHHOLD));
        } catch(InterruptedException e) {
            e.printStackTrace();
        }
        lock.lock();
        for(int i = START; i < STOP; i++)
            try {
                file.write(buffer.get());
            } catch(IOException e) {
                e.printStackTrace();
            }
        lock.unlock();
    }

}

これらのスレッドは両方とも、 を使用しExchangerて同じ種類のデータを交換します。smae の種類の 2 つのスレッド間ではなく、スレッド間Readerでのみ交換が行われるようにするにはどうすればよいですか?Writer