这是我调试了一天的代码出现很多问题报了很多错最后才调试通过。我看网上给的一些例子都有问题要不就是太简单现实中设计的通信协议是不会那么简单的。请大家放到Eclipse里面运行一下看看吧希望对大家有帮助。本示例中实现了一个通信协议访客端向座席端发送数据以BYTE_BUFFER_CAPACITY为块大小发送数据。每个块的前8个字节一个long型代表块内实际包含的有效字节数之后的字节都是潜在的有效字节数。当long型指定的有效字节数不足BYTE_BUFFER_CAPACITY-8时认为本次通信的消息结束。访客端每次接收9个字节作为一条消息超过9字节的部分认为是下一条服务器的回复消息。另外还有一点需要注意的是Java非阻塞式通信是“同步非阻塞式”的。比如说在读消息的时候如果不使用线程来处理就会把当前操作卡住无法继续处理其他客户端连接。有时间我会不断更新这篇博文争取把程序做成真实可用的二进制通信协议。服务端代码import java.io.ByteArrayOutputStream; import java.io.IOException; import java.net.InetSocketAddress; import java.nio.ByteBuffer; import java.nio.channels.SelectionKey; import java.nio.channels.Selector; import java.nio.channels.ServerSocketChannel; import java.nio.channels.SocketChannel; import java.util.Iterator; /** * 服务器端非阻塞式IOJava Server Socket Channel * author Bright Lee */ public class ServerSocketChannelTest { public static final int BYTE_BUFFER_CAPACITY 1024; public static void main(String[] args) { Selector selector null; ServerSocketChannel serverSocketChannel null; try { selector Selector.open(); serverSocketChannel ServerSocketChannel.open(); serverSocketChannel.bind(new InetSocketAddress(6666)); serverSocketChannel.configureBlocking(false); serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT); while (true) { SelectionKey selectionKey null; IteratorSelectionKey it null; try { if (selector.select() 0) { continue; } it selector.selectedKeys().iterator(); while (it.hasNext()) { selectionKey it.next(); it.remove(); if (!selectionKey.isValid()) { System.out.println(valid!); it.remove(); continue; } if (selectionKey.isAcceptable()) { handleAccept(selectionKey); } if (selectionKey.isReadable()) { handleRead(selectionKey); } if (selectionKey.isWritable()) { handleWrite(selectionKey); } if (selectionKey.isConnectable()) { System.out.println(connectable!); } } } catch (Exception e) { e.printStackTrace(); try { if (selectionKey ! null) { SocketChannel socketChannel (SocketChannel) selectionKey.channel(); socketChannel.close(); } } catch (Exception e1) { e1.printStackTrace(); } } } } catch (Exception e) { e.printStackTrace(); } finally { close(selector, serverSocketChannel); } } private static void handleAccept(SelectionKey selectionKey) throws IOException { System.out.println(acceptable!); ServerSocketChannel serverSocketChannel (ServerSocketChannel) selectionKey.channel(); SocketChannel socketChannel serverSocketChannel.accept(); socketChannel.configureBlocking(false); socketChannel.register(selectionKey.selector(), SelectionKey.OP_READ, new Attachment()); } private static void handleRead(SelectionKey selectionKey) throws IOException { //System.out.println(readable!); SocketChannel socketChannel (SocketChannel) selectionKey.channel(); Attachment readObject (Attachment) selectionKey.attachment(); ByteArrayOutputStream out readObject.getByteArrayOutputStream(); ByteBuffer buffer readObject.getByteBuffer(); socketChannel.read(buffer); if (buffer.capacity() - buffer.remaining() 8) { return; } buffer.flip(); long size IOUtil.readLong(buffer); long limit buffer.limit(); if (limit BYTE_BUFFER_CAPACITY) { for (int i 0; i size; i) { out.write(buffer.get()); } buffer.clear(); if (size BYTE_BUFFER_CAPACITY - 8) { String message new String(out.toByteArray(), UTF-8); System.out.println(接收到客户端发来的数据 message); socketChannel.register(selectionKey.selector(), SelectionKey.OP_WRITE); return; } } else { ByteArrayOutputStream baos new ByteArrayOutputStream(); IOUtil.writeLong(baos, size); while (buffer.hasRemaining()) { byte b buffer.get(); baos.write(b); } buffer.clear(); buffer.put(baos.toByteArray()); } } private static void handleWrite(SelectionKey selectionKey) throws IOException { //System.out.println(writable!); SocketChannel socketChannel (SocketChannel) selectionKey.channel(); StringBuilder buf new StringBuilder(9999); for (int i 0; i 50; i) { buf.append(A); } ByteBuffer buffer ByteBuffer.allocate(BYTE_BUFFER_CAPACITY); buffer.put(buf.toString().getBytes(UTF-8)); buffer.flip(); int limit buffer.limit(); int count 0; while (true) { int size socketChannel.write(buffer); count size; if (count limit) { break; } } Attachment attachment new Attachment(); socketChannel.register(selectionKey.selector(), SelectionKey.OP_READ, attachment); } private static void close(Selector selector, ServerSocketChannel serverSocketChannel) { try { if (selector ! null) { selector.close(); } } catch (Exception e) { e.printStackTrace(); } try { if (serverSocketChannel ! null) { serverSocketChannel.close(); } } catch (Exception e) { e.printStackTrace(); } } }客户端代码import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.Socket; import java.net.UnknownHostException; /** * 客户端阻塞式IOJava Socket。 * author Bright Lee */ public class SocketTest { public static void main(String[] args) throws UnknownHostException, IOException { while (true) { Socket socket null; OutputStream out null; InputStream in null; try { socket new Socket(127.0.0.1, 6666); socket.setKeepAlive(true); out socket.getOutputStream(); output(out); out.flush(); in socket.getInputStream(); byte[] bs input(in); String message new String(bs, UTF-8); System.out.println(接收到服务器端发来的消息message); } catch (Exception e) { e.printStackTrace(); break; } finally { close(out, in, socket); } } } private static void output(OutputStream out) throws IOException { StringBuilder buf new StringBuilder(99999); for (int i 0; i 1234; i) { buf.append(你好).append(i).append(,); } String s buf.toString(); byte[] bs s.getBytes(UTF-8); writeByteArray(out, bs); } private static void writeByteArray(OutputStream out, byte[] bs) throws IOException { if (bs null) { return; } int segmentSize ServerSocketChannelTest.BYTE_BUFFER_CAPACITY - 8; int segmentCount bs.length / segmentSize 1; int lastSegmentSize bs.length % segmentSize; int index -1; int length 0; for (int i 0; i segmentCount; i) { if (i segmentCount - 1) { IOUtil.writeLong(out, segmentSize); length segmentSize; index i * segmentSize; try { out.write(bs, index, length); } catch (Exception e) { e.printStackTrace(); } } else { IOUtil.writeLong(out, lastSegmentSize); length lastSegmentSize; index i * segmentSize; out.write(bs, index, length); out.write(new byte[segmentSize - length]); } } } private static byte[] input(InputStream in) throws IOException { ByteArrayOutputStream o new ByteArrayOutputStream(); int value -1; int count 0; while ((value in.read()) ! -1) { o.write(value); count; if (count 50) { break; } } byte[] bs2 o.toByteArray(); return bs2; } private static void close(OutputStream out, InputStream in, Socket socket) { try { if (out ! null) { out.close(); } } catch (Exception e) { e.printStackTrace(); } try { if (in ! null) { in.close(); } } catch (Exception e) { e.printStackTrace(); } try { if (socket ! null) { socket.close(); } } catch (Exception e) { e.printStackTrace(); } } }附件代码import java.io.ByteArrayOutputStream; import java.nio.ByteBuffer; /** * 读数据专用对象。 * author Bright Lee */ public class Attachment { private ByteArrayOutputStream out new ByteArrayOutputStream(9999); private ByteBuffer buffer ByteBuffer.allocate(ServerSocketChannelTest.BYTE_BUFFER_CAPACITY); private long need 0; private long count 0; public Attachment() { } public ByteArrayOutputStream getByteArrayOutputStream() { return out; } public ByteBuffer getByteBuffer() { return buffer; } public long getCount() { return count; } public void setCount(long count) { this.count count; } public long getNeed() { return need; } public void setNeed(long need) { this.need need; } }IO实用程序类import java.io.IOException; import java.io.OutputStream; import java.nio.ByteBuffer; public class IOUtil { public static void writeLong(OutputStream out, long value) throws IOException { byte[] bs new byte[8]; for (int i 0; i bs.length; i) { value value (i * 8); byte b (byte) (0x00FF value); bs[bs.length - i - 1] b; } out.write(bs); } public static long readLong(ByteBuffer buffer) { long value 0; for (int i 0; i 8; i) { byte b buffer.get(); value (value 8) | (0xFF b);; } return value; } }青蛙客服系统https://download.csdn.net/download/look4liming/93326820