我正在开发一个带有VPN服务的数据包嗅探器Android应用程序但我在读取从Fileinputstream到bytebuffer的数据包时遇到了麻烦。问题是每次我将数据包写入bytebuffer时,它都没有bytebuffer中的任何数据。请帮帮我。谢谢
FileInputStream in = new FileInputStream(traffic_interface.getFileDescriptor());
FileOutputStream out = new FileOutputStream(traffic_interface.getFileDescriptor());
DatagramChannel tunnel = DatagramChannel.open();
if (!protect(tunnel.socket())) {throw new IllegalStateException("Cannot protect the tunnel");}
tunnel.connect((new InetSocketAddress("127.0.0.1",0)));
tunnel.configureBlocking(false);
int n = 0;
while (!Thread.interrupted()){
packet = ByteBuffer.allocate(65535);
int packet_length = in.read(packet.array());
Log.d("UDPinStream","UDP:" +packet_length);
if(packet_length != -1 && packet_length > 0){
Log.d("UDPinStream","UDP:" + packet_length);
Log.d("UDPinStream","packet:" + packet);
packet.clear();
}
该问题占用以下代码
int packet_length = in.read(packet.array());
if(packet_length != -1 && packet_length > 0){
Log.d("UDPinStream","UDP:" + packet_length);
Log.d("UDPinStream","packet:" + packet);
packet.clear();
}
虽然它成功地从隧道中读取了数据包(packet_length> 0),但是字节缓冲区的pos中也没有数据在Bytebuffer数据包中没有变化。 java.nio.HeapByteBuffer [pos = 0 lim = 65535 cap = 65535]
ByteBuffers旨在与频道一起使用。您应该使用通道的任何读/写(ByteBuffer buf)接口来正确使用ByteBuffers。
无论如何,在你的片段中,read()获取byte [],写入它但ByteBuffer不知道它的后备数组被填充。所以,你可以这样做,
if (packet_length != -1 && packet_length > 0) {
packet.position(packet_length); // filled till that pos
packet.flip(); // No more writes, make it ready for reading
// Do read from packet buffer
// then, packet.clear() or packet.compact() to read again.
}
请继续关注NIO / ByteBuffer示例。