NIO 实例demo-Client

Client部分包括Client和ClientHandle两部分其中Client的时序通信图如下

Client.java

Client端启动主函数如下

package MyTestNetty.Server;/** * Created by User on 2017/8/4. */public class Client {    public static void main(String[] args) {        int port = 8080;//指定端口号        new Thread(new TimeClientHandle1("127.0.0.1",port),"myclient").start();//启动监听线程    }}

TimeClientHandle1.java

第二部分是ClientHandler部分代码如下：

package MyTestNetty.Server;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.SocketChannel;import java.util.Iterator;import java.util.Set;/** * Created by User on 2017/8/4. */public class TimeClientHandle1 implements Runnable {    private String host;    private int port;    private Selector selector;    private SocketChannel socketChannel;    private volatile boolean stop;    public TimeClientHandle1(String host, int port) {        this.host = host == null ? "127.0.0.1" : host;        this.port = port;        try {            selector = Selector.open();//创建selector实例            socketChannel = SocketChannel.open();//创建socketChannel实例            socketChannel.configureBlocking(false);//设置为异步        } catch (IOException e) {            e.printStackTrace();            System.exit(1);        }    }    @Override    public void run() {        try{            doConnect();        }catch (IOException e){            e.printStackTrace();            System.exit(1);        }        while (!stop){//轮询查询可用的key            try{                selector.select(1000);                Set<SelectionKey> selectionKeys = selector.selectedKeys();                Iterator<SelectionKey> it = selectionKeys.iterator();                SelectionKey key = null;                while (it.hasNext()){                    key = it.next();                    it.remove();                    try {                        hadleInput(key);                    }                    catch (Exception e){                        if(key!=null){                            key.cancel();                            if(key.channel()!=null)                                key.channel().close();                        }                    }                }            }catch (Exception e){                e.printStackTrace();                System.exit(1);            }        }        // 多路复用器关闭后，所有注册在上面的Channel和Pipe等资源都会被自动注册并关闭，所以不需要重新释放资源        if(selector!=null){            try {                selector.close();            }catch (IOException e){                e.printStackTrace();            }        }    }    private void hadleInput(SelectionKey key) throws IOException {        if(key.isValid()){            SocketChannel sc = (SocketChannel)key.channel();            if(key.isConnectable()){                if(sc.finishConnect()){                    sc.register(selector,SelectionKey.OP_READ);                    doWrite(sc);//向服务启发送请求（先写缓冲）                }else{                    System.exit(1);                }            }            if(key.isReadable()){//读取服务端返回的数据，从还缓冲中读数据                // read data                ByteBuffer readBuffer = ByteBuffer.allocate(1024);                int readBytes = sc.read(readBuffer);                if(readBytes>0){                    readBuffer.flip();                    byte[] bytes=new byte[readBuffer.remaining()];                    readBuffer.get(bytes);                    String body = new String(bytes,"UTF-8");                    System.out.println("Hello glad to see you : " + body);                    this.stop=true;                }                else if(readBytes<0){                    // 对端链路关闭                    key.cancel();                    sc.close();                }                else ; // 读到0字节，忽略            }        }    }    private void doConnect() throws IOException {        if(socketChannel.connect(new InetSocketAddress(host,port))){            socketChannel.register(selector,SelectionKey.OP_READ);            doWrite(socketChannel);        }else{            socketChannel.register(selector,SelectionKey.OP_CONNECT);        }    }    private void doWrite(SocketChannel sc) throws IOException {        byte[] req = "Clients ".getBytes();        ByteBuffer writeBuffer = ByteBuffer.allocate(req.length);        writeBuffer.put(req);        writeBuffer.flip();        sc.write(writeBuffer);        if(!writeBuffer.hasRemaining()){            System.out.println("send order to server succeed!");        }    }}

这一部分主要是包括向服务器发送请求，以及接受来自server的信息，启动运行后可输出一下结果表示服务端启动成功（本例中我们向服务器发送的是Clients 字符串）服务器给我们反馈的是Server）

并且在服务端的控制台输出如下：

这个简单的服务器客户端NIO通信的简单demo