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1 parent 29927f0 commit 68cc444

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Lines changed: 3181 additions & 2 deletions

‎dom4j.xml‎

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<?xml version="1.0" encoding="UTF-8" ?>
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<dom4j>
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<name littleName="属性值">dom4j模板</name>
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<age littleName="20">20</age>
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</dom4j>

‎src/com/yale/test/io/nio/AClient.java‎

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package com.yale.test.io.nio;
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import java.io.IOException;
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public class AClient {
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public static void main(String[] args) throws IOException {
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new NioClient().start("AClient");
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}
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}

‎src/com/yale/test/io/nio/BClient.java‎

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package com.yale.test.io.nio;
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import java.io.IOException;
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public class BClient {
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public static void main(String[] args) throws IOException {
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new NioClient().start("BClient");
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}
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}

‎src/com/yale/test/io/nio/Buffer.png‎

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‎src/com/yale/test/io/nio/CClient.java‎

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package com.yale.test.io.nio;
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import java.io.IOException;
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public class CClient {
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public static void main(String[] args) throws IOException {
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new NioClient().start("CClient");
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}
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}

‎src/com/yale/test/io/nio/Channel.png‎

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‎src/com/yale/test/io/nio/ChannelDemo.png‎

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‎src/com/yale/test/io/nio/NioClient.java‎

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package com.yale.test.io.nio;
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import java.io.IOException;
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import java.net.InetSocketAddress;
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import java.nio.channels.SelectionKey;
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import java.nio.channels.Selector;
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import java.nio.channels.SocketChannel;
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import java.nio.charset.Charset;
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import java.util.Scanner;
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public class NioClient {
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public void start(String nickName) throws IOException {
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//连接服务器端
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SocketChannel socketChannel = SocketChannel.open(new InetSocketAddress("127.0.0.1", 8000));
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//新开线程,专门负责来接收服务器端的响应数据
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Selector selector = Selector.open();
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socketChannel.configureBlocking(false);//设置为非阻塞模式
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//将socketChannel注册到selector上面,监听selector的可读事件
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socketChannel.register(selector, SelectionKey.OP_READ);
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new Thread(new NioClientHandler(selector)).start();//新开线程
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Scanner scanner = new Scanner(System.in);
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//向服务器端发送数据
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while (scanner.hasNextLine()) {
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String request = scanner.nextLine();
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if (request != null && request.length() > 0) {
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socketChannel.write(Charset.forName("UTF-8").encode(nickName + ":" +request));
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}
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}
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}
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public static void main(String[] args) throws IOException {
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//new NioClient().start();
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}
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}

‎src/com/yale/test/io/nio/NioClientHandler.java‎

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package com.yale.test.io.nio;
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import java.io.IOException;
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import java.nio.ByteBuffer;
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import java.nio.channels.SelectionKey;
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import java.nio.channels.Selector;
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import java.nio.channels.SocketChannel;
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import java.nio.charset.Charset;
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import java.util.Iterator;
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import java.util.Set;
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public class NioClientHandler implements Runnable{
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private Selector selector;
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public NioClientHandler(Selector selector) {
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this.selector = selector;
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}
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@Override
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public void run() {
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try {
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for (;;) {//相当于while(true)循环,for;;JVM会优化成一条语句,while(true)会优化成3条语句,JAVA源码很多都是for;;
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/**
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* 获取可用的Channel数量
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*/
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int readyChannels = selector.select();
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if (readyChannels == 0) {
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continue;
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}
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Set<SelectionKey> selectorKeys = selector.selectedKeys();
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Iterator iterator = selectorKeys.iterator();
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while(iterator.hasNext()) {
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//获取SelectionKey实例
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SelectionKey selectionKey = (SelectionKey)iterator.next();
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//移除Set中的当前SelectionKey
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iterator.remove();
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//可读事件,根据就绪状态,调用对应的方法处理业务逻辑
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if (selectionKey.isReadable()) {
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readHandler(selectionKey, selector);
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}
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}
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}
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} catch (IOException e) {
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e.printStackTrace();
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}
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}
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//可读事件处理
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private void readHandler(SelectionKey selectionKey, Selector selector) throws IOException {
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//要从selectionKey中获取到已经就绪的channel
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SocketChannel socketChannel = (SocketChannel)selectionKey.channel();
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//创建Buffer
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ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
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//循环读取服务器端的响应信息
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String response = "";
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while (socketChannel.read(byteBuffer) > 0) {
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byteBuffer.flip();//切换到读模式
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response += Charset.forName("UTF-8").decode(byteBuffer);
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}
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//将channel再次注册到Selector上,监听他的可读事件
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socketChannel.register(selector, SelectionKey.OP_READ);
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if (response.length() > 0) {//将服务器端响应信息打印到本地
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System.out.println(response);
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}
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}
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}

‎src/com/yale/test/io/nio/NioServer.java‎

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import java.io.IOException;
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import java.net.InetSocketAddress;
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import java.nio.ByteBuffer;
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import java.nio.channels.Channel;
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import java.nio.channels.SelectionKey;
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import java.nio.channels.Selector;
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import java.nio.channels.ServerSocketChannel;
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import java.nio.channels.SocketChannel;
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import java.nio.charset.Charset;
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import java.util.Iterator;
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import java.util.Set;
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/**
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* NIO服务器
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* NIO Non Blocking io非阻塞IO JDK1.4有的
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* NIO网络编程缺陷
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* 麻烦:NIO类库和API繁杂
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* 心累:可靠性能力补齐,工作量和难度都非常大
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* 有坑:Selector空轮询,导致CPU100%
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* @author dell
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*/
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public class NioServer {
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*/
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int readyChannels = selector.select();
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if (readyChannels == 0) {
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/**
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* 这里有坑:Selector空轮询,导致CPU100%
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* 主要出现在类Unix上面,这个问题java官方声称在jdk1.6的版本中已经修复,
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* 但实际证明该问题在jdk1.8上面依然存在,只不过发生的概率低了一些.
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* 如果要在Linux上面使用,要非常小心,最好不用,老师没说替代办法
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*/
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continue;
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}
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//移除Set中的当前SelectionKey
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iterator.remove();
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//接入事件,根据就绪状态,调用对应的方法处理业务逻辑
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if (selectionKey.isAcceptable()) {
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acceptHandler(serverSocketChannel, selector);
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}
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//可读事件,根据就绪状态,调用对应的方法处理业务逻辑
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if (selectionKey.isReadable()) {
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readHandler(selectionKey, selector);
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}
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}
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}
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}
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//接入事件处理
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private void acceptHandler(ServerSocketChannel serverSocketChannel, Selector selector) throws IOException {
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//如果是接入事件,创建SocketChannel
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SocketChannel socketChannel = serverSocketChannel.accept();
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socketChannel.configureBlocking(false);//将socketChannel设置为非阻塞工作模式
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//将channel注册到selector上,监听可读事件
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socketChannel.register(selector, SelectionKey.OP_READ);
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//回复客户端提示信息
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socketChannel.write(Charset.forName("UTF-8").encode("你与聊天室里其他人不是朋友关系,请注意隐私安全"));
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}
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//可读事件处理
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private void readHandler(SelectionKey selectionKey, Selector selector) throws IOException {
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//要从selectionKey中获取到已经就绪的channel
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SocketChannel socketChannel = (SocketChannel)selectionKey.channel();
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//创建Buffer
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ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
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//循环读取客户端的请求信息
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String request = "";
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while (socketChannel.read(byteBuffer) > 0) {
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byteBuffer.flip();//切换到读模式
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request += Charset.forName("UTF-8").decode(byteBuffer);
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}
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//将channel再次注册到Selector上,监听他的可读事件
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socketChannel.register(selector, SelectionKey.OP_READ);
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if (request.length() > 0) {//将客户端发送的请求消息光博给其他客户端
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System.out.println(":::" + request);
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broadCast(selector, socketChannel, request);
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}
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}
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//广播给其他所有客户端
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private void broadCast(Selector selector, SocketChannel sourceChannel, String request) {
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//获取到所有已接入的客户端channel
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Set<SelectionKey> selectionKeySet = selector.keys();
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//
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selectionKeySet.forEach(selectionKey ->{//循环向所有channel广播信息
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Channel targetChannel = selectionKey.channel();
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//删除发送消息的客户端
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if (targetChannel instanceof SocketChannel && targetChannel != sourceChannel) {
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try {//将消息发送到targetChannel客户端
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((SocketChannel)targetChannel).write(Charset.forName("UTF-8").encode(request));
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} catch (IOException e) {
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e.printStackTrace();
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}
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}
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});
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}
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public static void main(String[] args) throws IOException {
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NioServer nioServer = new NioServer();
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nioServer.start();
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}
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}

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