private void recv(SocketChannel sc, ClientInfo ci) throws IOException { ci.channel.read(ci.inBuf); ByteBuffer tmpBuf = ci.inBuf.duplicate(); tmpBuf.flip(); int bytesProcessed = 0; boolean doneLoop = false; while (!doneLoop) { byte b; try { b = tmpBuf.get(); } catch (BufferUnderflowException bue) { // Processed all data in buffer ci.inBuf.clear(); doneLoop = true; break; } switch (b) { case TypeServerConstants.WELCOME: bytesProcessed++; break; case TypeServerConstants.GET_STRING_REQUEST: bytesProcessed++; if (ci.outputPending) { // Client is backed up. We can't append to // the byte buffer because it's in the wrong // state. We could allocate another buffer // here and change our send method to know // about multiple buffers, but we'll just // assume that the client is dead break; } ci.outBuf.put(TypeServerConstants.GET_STRING_RESPONSE); ByteBuffer strBuf = encoder.encode(testString); ci.outBuf.putShort((short) strBuf.remaining()); ci.outBuf.put(strBuf); ci.outBuf.flip(); send(sc, ci); break; case TypeServerConstants.GET_STRING_RESPONSE: int startPos = tmpBuf.position(); try { int nBytes = tmpBuf.getInt(); byte[] buf = new byte[nBytes]; tmpBuf.get(buf); bytesProcessed += buf.length + 5; String s = new String(buf); // Send the string to the GUI break; } catch (BufferUnderflowException bue) { // Processed all available data ci.inBuf.position(ci.inBuf.position() + bytesProcessed); doneLoop = true; } break; } } }
public static void main(String args[]) throws Exception { final int ENOUGH_SIZE = 1024; final int SMALL_SIZE = 4; boolean isBlocked = true; int size = ENOUGH_SIZE; if (args.length > 0) { int opt = Integer.parseInt(args[0]); switch (opt) { case 1: isBlocked = true; size = ENOUGH_SIZE; break; case 2: isBlocked = true; size = SMALL_SIZE; break; case 3: isBlocked = false; size = ENOUGH_SIZE; break; case 4: isBlocked = false; size = SMALL_SIZE; break; } } DatagramChannel channel = DatagramChannel.open(); channel.configureBlocking(isBlocked); ByteBuffer buffer = ByteBuffer.allocate(size); DatagramSocket socket = channel.socket(); SocketAddress localAddr = new InetSocketAddress(8000); socket.bind(localAddr); while (true) { System.out.println("开始接收数据报"); SocketAddress remoteAddr = channel.receive(buffer); if (remoteAddr == null) { System.out.println("没有接收到数据报"); } else { buffer.flip(); System.out.println("接收到的数据报的大小为" + buffer.remaining()); } Thread.sleep(500); } }
private synchronized DBMessage go(DBMessage msg, ByteDecoder decoder) throws IOException { if (_sock == null) _open(); { ByteBuffer out = msg.prepare(); while (out.remaining() > 0) _sock.write(out); } if (_pool != null) _pool._everWorked = true; if (decoder == null) return null; ByteBuffer response = decoder._buf; if (response.position() != 0) throw new IllegalArgumentException(); int read = 0; while (read < DBMessage.HEADER_LENGTH) read += _read(response); int len = response.getInt(0); if (len <= DBMessage.HEADER_LENGTH) throw new IllegalArgumentException("db sent invalid length: " + len); if (len > response.capacity()) throw new IllegalArgumentException( "db message size is too big (" + len + ") " + "max is (" + response.capacity() + ")"); response.limit(len); while (read < len) read += _read(response); if (read != len) throw new RuntimeException("something is wrong"); response.flip(); return new DBMessage(response); }
private int _read(ByteBuffer buf) throws IOException { int x = _in.read(buf.array(), buf.position(), buf.remaining()); if (x < 0) throw new IOException("connection to server closed unexpectedly"); buf.position(buf.position() + x); return x; }
private void readMessage(SelectionKey sk, SocketChannel readChannel, TcpAddress incomingAddress) throws IOException { // note that socket has been used SocketEntry entry = (SocketEntry) sockets.get(incomingAddress); if (entry != null) { entry.used(); ByteBuffer readBuffer = entry.getReadBuffer(); if (readBuffer != null) { readChannel.read(readBuffer); if (readBuffer.hasRemaining()) { readChannel.register(selector, SelectionKey.OP_READ, entry); } else { dispatchMessage(incomingAddress, readBuffer, readBuffer.capacity()); } return; } } ByteBuffer byteBuffer = ByteBuffer.wrap(buf); byteBuffer.limit(messageLengthDecoder.getMinHeaderLength()); long bytesRead = readChannel.read(byteBuffer); if (logger.isDebugEnabled()) { logger.debug("Reading header " + bytesRead + " bytes from " + incomingAddress); } MessageLength messageLength = new MessageLength(0, Integer.MIN_VALUE); if (bytesRead == messageLengthDecoder.getMinHeaderLength()) { messageLength = messageLengthDecoder.getMessageLength(ByteBuffer.wrap(buf)); if (logger.isDebugEnabled()) { logger.debug("Message length is " + messageLength); } if ((messageLength.getMessageLength() > getMaxInboundMessageSize()) || (messageLength.getMessageLength() <= 0)) { logger.error( "Received message length " + messageLength + " is greater than inboundBufferSize " + getMaxInboundMessageSize()); synchronized (entry) { entry.getSocket().close(); logger.info("Socket to " + entry.getPeerAddress() + " closed due to an error"); } } else { byteBuffer.limit(messageLength.getMessageLength()); bytesRead += readChannel.read(byteBuffer); if (bytesRead == messageLength.getMessageLength()) { dispatchMessage(incomingAddress, byteBuffer, bytesRead); } else { byte[] message = new byte[byteBuffer.limit()]; byteBuffer.flip(); byteBuffer.get(message, 0, byteBuffer.limit() - byteBuffer.remaining()); entry.setReadBuffer(ByteBuffer.wrap(message)); } readChannel.register(selector, SelectionKey.OP_READ, entry); } } else if (bytesRead < 0) { logger.debug("Socket closed remotely"); sk.cancel(); readChannel.close(); TransportStateEvent e = new TransportStateEvent( DefaultTcpTransportMapping.this, incomingAddress, TransportStateEvent.STATE_DISCONNECTED_REMOTELY, null); fireConnectionStateChanged(e); } }