Java 异步通信 程序

Java异步通信

服务器端：

package cn.xiao; import java.net.InetSocketAddress; import java.net.Socket; import java.net.SocketAddress; import java.nio.ByteBuffer; import java.nio.CharBuffer; import java.nio.channels.SelectionKey; import java.nio.channels.Selector; import java.nio.channels.ServerSocketChannel; import java.nio.channels.SocketChannel; import java.nio.charset.Charset; import java.nio.charset.CharsetDecoder; import java.nio.charset.CharsetEncoder; import java.util.Iterator; public class TCPServer { protected Selector selector; protected Charset charset = Charset.forName("UTF-8"); protected CharsetEncoder charsetEncoder = charset.newEncoder(); protected CharsetDecoder charsetDecoder = charset.newDecoder(); int count = 1; /** * @throws Exception */ public TCPServer() throws Exception{ this(8888); } /** * @param port * @throws Exception */ public TCPServer(int port) throws Exception { selector = Selector.open(); ServerSocketChannel ssc = ServerSocketChannel.open(); ssc.socket().bind(new InetSocketAddress(port)); // port ssc.configureBlocking(false); ssc.register(selector, SelectionKey.OP_ACCEPT);// register while (true) { // selector 线程。select() 会阻塞，直到有客户端连接，或者有消息读入 selector.select(); Iterator iterator = selector.selectedKeys().iterator(); while (iterator.hasNext()) { SelectionKey selectionKey = iterator.next(); iterator.remove(); // 删除此消息 // 并在当前线程内处理 handleSelectionKey(selectionKey); } } } /** * @param selectionKey * @throws Exception */ public void handleSelectionKey(SelectionKey selectionKey) throws Exception { if (selectionKey.isAcceptable()) { ServerSocketChannel ssc = (ServerSocketChannel) selectionKey.channel(); SocketChannel socketChannel = ssc.accept(); socketChannel.configureBlocking(false); Socket socket = socketChannel.socket(); // 立即注册一个 OP_READ 的SelectionKey, 接收客户端的消息 SelectionKey key = socketChannel.register(selector,SelectionKey.OP_READ); SocketAddress clientInfo = socket.getRemoteSocketAddress(); key.attach("第 " + (count++) + " 个客户端 [" + clientInfo + "]"); // 打印 println(key.attachment() + " 连接成功"); } else if (selectionKey.isReadable()) { // 有消息进来 ByteBuffer byteBuffer = ByteBuffer.allocate(100); SocketChannel sc = (SocketChannel) selectionKey.channel(); try { int len = sc.read(byteBuffer); // 如果len>0，表示有输入。如果len==0, 表示输入结束。需要关闭 socketChannel if (len > 0) { byteBuffer.flip(); String msg = charsetDecoder.decode(byteBuffer).toString(); println(selectionKey.attachment() + " ：" + msg); // 根据客户端的消息，查找到对应的输出 String newMsg = "****************"; ByteBuffer bt = charsetEncoder.encode(CharBuffer.wrap(newMsg + "\n")); sc.write(bt); } else { // 输入结束，关闭 socketChannel println(selectionKey.attachment()+ " 已关闭连接"); sc.close(); } } catch (Exception e) { // 如果read抛出异常，表示连接异常中断，需要关闭 socketChannel e.printStackTrace(); sc.close(); } } else if (selectionKey.isWritable()) { println("TODO: isWritable()"); } else if (selectionKey.isConnectable()) { println("TODO: isConnectable()"); } else { println("TODO: else"); } } /** * @param object */ public static void println(Object object) { System.out.println(object); } /** * @param args * @throws Exception */ public static void main(String[] args) throws Exception { new TCPServer(); } }

客户端：

package cn.xiao; import java.io.BufferedReader; import java.io.InputStreamReader; import java.io.OutputStream; import java.net.Socket; import java.io.InputStream; public class TCPClient extends Thread { public void run() { try { Socket socket = new Socket("127.0.0.1", 8888); OutputStream ous = socket.getOutputStream(); InputStream ins = socket.getInputStream(); BufferedReader r = new BufferedReader(new InputStreamReader(ins, "UTF-8")); // 发送服务器 ous.write(">>>>>>>>>>>>>>>>".getBytes("UTF-8")); ous.flush(); // 接收给服务器 System.out.println(">>>> " + r.readLine()); // 发送服务器 ous.write("<<<<<<<<<<<<<<<<".getBytes("UTF-8")); ous.flush(); // 接收服务器 System.out.println(">>>> " + r.readLine()); Thread.sleep(3*1000); ins.close(); ous.close(); socket.close(); } catch (Exception e) { e.printStackTrace(); } } /** * @param args * @throws Exception */ public static void main(String[] args) throws Exception { for (int i = 0; i < 3; i++) { try { new TCPClient().start(); } catch (Exception e) { e.printStackTrace(); } } } }

我是业余的，复制，粘贴代码就可运行，原理要自己领悟哈！