java使用selector NIO socket

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使用NIO的socket时一直测试状态是服务端返回的信息所有客户端都能收到一直很郁闷后来发现是服务端代码的问题在接受到一个channel时我的代码里是拿select又做了一次遍历对所有的客户端进行返回

下面给一个代码示例

服务端

public class HansServer {    // 用于检测所有Channel状态的Selector    private Selector selector = null;    public void init() throws IOException {        selector = Selector.open();        // 通过open方法来打开一个未绑定的ServerSocketChannel实例        ServerSocketChannel server = ServerSocketChannel.open();        InetSocketAddress isa = new InetSocketAddress("127.0.0.1", 30000);        // 将该ServerSocketChannel绑定到指定IP地址        server.socket().bind(isa);        // 设置ServerSocket以非阻塞方式工作        server.configureBlocking(false);        // 将server注册到指定Selector对象        server.register(selector, SelectionKey.OP_ACCEPT);        while (selector.select() > 0) {            // 依次处理selector上的每个已选择的SelectionKey            for (SelectionKey sk : selector.selectedKeys()) {                // 从selector上的已选择Key集中删除正在处理的SelectionKey                selector.selectedKeys().remove(sk);                // 如果sk对应的通道包含客户端的连接请求                if (sk.isAcceptable()) {                    // 调用accept方法接受连接，产生服务器端对应的SocketChannel                ServerSocketChannel ssc =(ServerSocketChannel) sk.channel();                    SocketChannel sc = ssc.accept();//                    SocketChannel sc = server.accept();                    // 设置采用非阻塞模式                    sc.configureBlocking(false);                    // 将该SocketChannel也注册到selector                    sc.register(selector, SelectionKey.OP_READ);                }                // 如果sk对应的通道有数据需要读取                if (sk.isReadable()) {                    // 获取该SelectionKey对应的Channel，该Channel中有可读的数据                    SocketChannel sc = (SocketChannel) sk.channel();                    // 定义准备执行读取数据的ByteBuffer                    ByteBuffer buff = ByteBuffer.allocate(1024);                    String content = "";                    byte[] receData =new byte[0];                    byte[] temp =new byte[1];                    // 开始读取数据                    try {     while(sc.read(buff)> 0){     sc.read(buff);     buff.flip();                        int limit = buff.limit();     temp =new byte[limit];                     buff.get(temp,0,limit);                     byte[] and = new byte[temp.length+receData.length];                     System.arraycopy(receData, 0, and, 0, receData.length);                     System.arraycopy(temp, 0, and, receData.length, temp.length);                     receData=and;                                           buff.clear();                     }     content += StandardCharsets.UTF_8.decode(ByteBuffer.wrap(receData));                        if(sc.read(buff)  == -1){                            System.out.println("断开..."                                     + sc.socket().getRemoteSocketAddress());                                        sk.cancel();                            if (sk.channel() != null) {                                sk.channel().close();                                sc.close();                            }                        }else{                        // 打印从该sk对应的Channel里读取到的数据                        System.out.println("=====接收到客户端数据：" + content);                        if (content.length() > 0) {                            sc.write(StandardCharsets.UTF_8.encode("服务端发送："+content+"---已收到！！！"));                            }                        }                    }                    // 如果捕捉到该sk对应的Channel出现了异常，即表明该Channel                    // 对应的Client出现了问题，所以从Selector中取消sk的注册                    catch (IOException ex) {                        // 从Selector中删除指定的SelectionKey                        sk.cancel();                        if (sk.channel() != null) {                            sk.channel().close();                            sc.close();                        }                    }                    // 如果content的长度大于0，即聊天信息不为空//                    if (content.length() > 0) {////                        // 遍历该selector里注册的所有SelectKey////                        for (SelectionKey key : selector.keys()) {////                            // 获取该key对应的Channel////                            Channel targetChannel = key.channel();////                            // 如果该channel是SocketChannel对象////                            if (targetChannel instanceof SocketChannel) {////                                // 将读到的内容写入该Channel中////                                SocketChannel dest = (SocketChannel) targetChannel;////                                dest.write(StandardCharsets.UTF_8.encode("服务端发送："+content+"---已收到！！！"));////                            }////                        }//                    }                }            }        }    }    public static void main(String[] args) throws IOException {        new HansServer().init();    }}

客户端

public class HansClient {    // 定义检测SocketChannel的Selector对象    private Selector selector = null;    // 客户端SocketChannel    private SocketChannel sc = null;    public void init() throws IOException {        selector = Selector.open();        InetSocketAddress isa = new InetSocketAddress("127.0.0.1", 30000);        // 调用open静态方法创建连接到指定主机的SocketChannel        sc = SocketChannel.open(isa);        // 设置该sc以非阻塞方式工作        sc.configureBlocking(false);        // 将SocketChannel对象注册到指定Selector        sc.register(selector, SelectionKey.OP_READ);        // 创建键盘输入流//        Scanner scan = new Scanner(System.in);//        while (scan.hasNextLine()) {        // 读取键盘输入        int SendRes = new HansClient().S_SendData(sc);        System.out.println("发送数据返回值"+SendRes);//        }        // 启动读取服务器端数据的线程//        new ClientThread().start();        new HansClient().S_ResData(selector);                 sc.close();         selector.close();    }    public int S_SendData(SocketChannel sc ){    int sendRes =0;    String line = "6*7";    // 将键盘输入的内容输出到SocketChannel中    try { sendRes = sc.write(StandardCharsets.UTF_8.encode(line));} catch (IOException e) {e.printStackTrace();}    return sendRes;    }    public void S_ResData(Selector sele){     try {             while (sele.select() > 0) {                 // 遍历每个有可用IO操作Channel对应的SelectionKey                 for (SelectionKey sk : sele.selectedKeys()) {                     // 删除正在处理的SelectionKey                 sele.selectedKeys().remove(sk);                     // 如果该SelectionKey对应的Channel中有可读的数据                     if (sk.isReadable()) {                         // 使用NIO读取Channel中的数据                         SocketChannel sc = (SocketChannel) sk.channel();                         ByteBuffer buff = ByteBuffer.allocate(5);                         String content = "";                         byte[] receData =new byte[0];                     byte[] temp =new byte[1];     while(sc.read(buff)> 0){     sc.read(buff);                     temp = buff.array();                     byte[] and = new byte[temp.length+receData.length];                     System.arraycopy(receData, 0, and, 0, receData.length);                     System.arraycopy(temp, 0, and, receData.length, temp.length);                     receData=and;                      buff.flip();                      buff.clear();                     }     content += StandardCharsets.UTF_8.decode(ByteBuffer.wrap(receData));                         // 打印输出读取的内容                         System.out.println("聊天信息：" + content);                        break;                     }                 }                 break;             }         } catch (IOException ex) {             ex.printStackTrace();         }    }

 public static void main(String[] args) throws IOException {        new HansClient().init();    }}

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