Replay PCAP data over a socket

App.java

package org.opennms;

import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.WritableByteChannel;
import java.util.concurrent.TimeUnit;

import org.pcap4j.core.BpfProgram;
import org.pcap4j.core.NotOpenException;
import org.pcap4j.core.PacketListener;
import org.pcap4j.core.PcapHandle;
import org.pcap4j.core.PcapNativeException;
import org.pcap4j.core.Pcaps;
import org.pcap4j.packet.TcpPacket;

public class App {

    private static ByteBuffer toByteBuffer(String pcap, String filter) throws PcapNativeException, NotOpenException, InterruptedException {
        final PcapHandle handle = Pcaps.openOffline(pcap, PcapHandle.TimestampPrecision.NANO);
        handle.setFilter(filter, BpfProgram.BpfCompileMode.OPTIMIZE);

        ByteBuffer byteBuffer = ByteBuffer.allocate(8192*64);
        PacketListener listener = packet -> {
            TcpPacket tcpPacket = packet.get(TcpPacket.class);
            byte[] bytes = tcpPacket.getPayload().getRawData();
            byteBuffer.put(bytes);
        };

        handle.loop(0, listener);
        handle.close();
        return byteBuffer;
    }

    public static void main( String[] args ) throws PcapNativeException, NotOpenException, InterruptedException {
        String pcap = "/home/jesse/Downloads/bmp-reset-pcap/bmp-juniper.pcap";
        String filter = "tcp dst port 11019";
        String hostname = "localhost";
        int port = 5000;

        ByteBuffer bytes = toByteBuffer(pcap, filter);
        int bytesAvail = bytes.position();
        System.out.printf("Read %d bytes from .pcap\n", bytesAvail);

        bytes.rewind();
        bytes.limit(bytesAvail);

        try (Socket socket = new Socket(hostname, port)) {
            OutputStream os = socket.getOutputStream();
            WritableByteChannel channel = Channels.newChannel(os);
            channel.write(bytes);
            System.out.println("All bytes sent. Sleeping...");
            Thread.sleep(TimeUnit.MINUTES.toMillis(5));
        } catch (IOException e) {
            System.out.println("I/O error: " + e.getMessage());
        }
    }
}