java nio之selector

Selector selector = Selector.open();

socketChannel.configureBlocking(false);

socketChannel.register(selector, SelectionKey.OP_READ)

SelectionKey.OP_CONNECT SelectionKey.OP_ACCEPT SelectionKey.OP_READ SelectionKey.OP_WRITE

selector.selectedKeys() //获取所有选择键selectionKey.isConnectable() //是否是连接选择键selectionKey.isReadable() //读取selectionKey.isWritable() //写入selectionKey.isAcceptable() //接收

SocketChannel channel = (SocketChannel) selectionKey.channel();

package com.troy.nio.application;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;public class Client {    //选择器    private static Selector selector;    //通信管道    private static SocketChannel socketChannel;    public static void main(String[] args) {        try {            clientInit();            listen();            //发送数据            while (true) {                Thread.sleep(1000);                socketChannel.write(ByteBuffer.wrap(("hello server!").getBytes()));            }        } catch (Exception e) {            e.printStackTrace();        }    }    //初始化选择器和发送数据    private static void clientInit() throws Exception {        //打开一个通道管理器        selector = Selector.open();        //获取一个通信管道        socketChannel = SocketChannel.open();        //设置对应的发送地址和端口        socketChannel.connect(new InetSocketAddress("localhost",9000));        //设置非阻塞        socketChannel.configureBlocking(false);        //注册一个写入事件        socketChannel.register(selector, SelectionKey.OP_READ);    }    //监听服务器返回的数据    private static void listen() throws Exception {        Runnable runnable = () -> {            while (true) {                try {                    //这里会一直阻塞，直到事件过来                    selector.select();                    //在选择器中获取对应的注册事件                    Iterator<SelectionKey> iterator = selector.selectedKeys().iterator();                    while (iterator.hasNext()) {                        //注册事件                        SelectionKey selectionKey = iterator.next();                        iterator.remove();                        //判断是否是读事件                        if (selectionKey.isReadable()) {                            //获取对应通信管道，并处理层数据                            SocketChannel channel = (SocketChannel) selectionKey.channel();                            //一次性读取数据量，这里应该做循环，我这里方便没有做                            ByteBuffer byteBuffer = ByteBuffer.allocate(1024);                            channel.read(byteBuffer);                            byteBuffer.flip();                            System.out.println(new String(byteBuffer.array()).trim());                        }                    }                } catch (Exception e) {                    throw new RuntimeException(e.getMessage());                }            }        };        new Thread(runnable).start();    }}

package com.troy.nio.application;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;public class Server {    //选择器    private static Selector selector;    //服务端通信管道    private static ServerSocketChannel channel;    public static void main(String[] args) {        try {            serverInit();            listen();        } catch (Exception e) {            e.printStackTrace();        }    }    //初始化    private static void serverInit() throws IOException {        //打开一个选择器        selector = Selector.open();        //打开一个服务端通信管道        channel = ServerSocketChannel.open();        //设置接收端口        channel.socket().bind(new InetSocketAddress(9000));        //设置非阻塞        channel.configureBlocking(false);        //注册接收事件        channel.register(selector, SelectionKey.OP_ACCEPT);    }    //监听    private static void listen() throws IOException {        while (true) {            //形成阻塞事件，接口完成后进行下一步            selector.select();            //获取选择器中的事件            Iterator<SelectionKey> iterator = selector.selectedKeys().iterator();            while (iterator.hasNext()) {                SelectionKey selectionKey = iterator.next();                iterator.remove();                //判断是否是接受事件                if (selectionKey.isAcceptable()) {                    SocketChannel socketChannel = channel.accept();                    socketChannel.configureBlocking(false);                    socketChannel.register(selector,SelectionKey.OP_READ);                }                //是否是可读事件                if (selectionKey.isReadable()) {                    SocketChannel socketChannel = (SocketChannel) selectionKey.channel();                    ByteBuffer byteBuffer = ByteBuffer.allocate(1024);                    //这里的目的是当这个服务端一直存在，因为读取数据存在异常，直接处理掉，下一个客户端景来可以继续接受                    try {                        socketChannel.read(byteBuffer);                    } catch (Exception e) {
　　　　　　　　　　　　　　selectionKey.cancel();                        continue;                    }                    byteBuffer.flip();                    System.out.println(new String(byteBuffer.array()).trim());                    socketChannel.write(ByteBuffer.wrap("hello client!".getBytes()));                }            }        }    }}