java nio实战代码.rar

package com.atguigu.server; import java.io.IOException; import java.net.InetSocketAddress; import java.nio.ByteBuffer; import java.nio.channels.*; import java.nio.charset.Charset; import java.util.Iterator; import java.util.Set; //服务器端 public class ChatServer { //服务器端启动的方法 public void startServer() throws IOException { //1 创建Selector选择器 Selector selector = Selector.open(); //2 创建ServerSocketChannel通道 ServerSocketChannel serverSocketChannel = ServerSocketChannel.open(); //3 为channel通道绑定监听端口 serverSocketChannel.bind(new InetSocketAddress(8000)); //设置非阻塞模式 serverSocketChannel.configureBlocking(false); //4 把channel通道注册到selector选择器上 serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT); System.out.println("服务器已经启动成功了"); //5 循环，等待有新链接接入 //while(true) for(;;) { //获取channel数量 int readChannels = selector.select(); if(readChannels == 0) { continue; } //获取可用的channel Set<SelectionKey> selectionKeys = selector.selectedKeys(); //遍历集合 Iterator<SelectionKey> iterator = selectionKeys.iterator(); while (iterator.hasNext()) { SelectionKey selectionKey = iterator.next(); //移除set集合当前selectionKey iterator.remove(); //6 根据就绪状态，调用对应方法实现具体业务操作 //6.1 如果accept状态 if(selectionKey.isAcceptable()) { acceptOperator(serverSocketChannel,selector); } //6.2 如果可读状态 if(selectionKey.isReadable()) { readOperator(selector,selectionKey); } } } } //处理可读状态操作 private void readOperator(Selector selector, SelectionKey selectionKey) throws IOException { //1 从SelectionKey获取到已经就绪的通道 SocketChannel socketChannel = (SocketChannel)selectionKey.channel(); //2 创建buffer ByteBuffer byteBuffer = ByteBuffer.allocate(1024); //3 循环读取客户端消息 int readLength = socketChannel.read(byteBuffer); String message = ""; if(readLength >0) { //切换读模式 byteBuffer.flip(); //读取内容 message += Charset.forName("UTF-8").decode(byteBuffer); } //4 将channel再次注册到选择器上，监听可读状态 socketChannel.register(selector,SelectionKey.OP_READ); //5 把客户端发送消息，广播到其他客户端 if(message.length()>0) { //广播给其他客户端 System.out.println(message); castOtherClient(message,selector,socketChannel); } } //广播到其他客户端 private void castOtherClient(String message, Selector selector, SocketChannel socketChannel) throws IOException { //1 获取所有已经接入channel Set<SelectionKey> selectionKeySet = selector.keys(); //2 循环想所有channel广播消息 for(SelectionKey selectionKey : selectionKeySet) { //获取每个channel Channel tarChannel = selectionKey.channel(); //不需要给自己发送 if(tarChannel instanceof SocketChannel && tarChannel != socketChannel) { ((SocketChannel)tarChannel).write(Charset.forName("UTF-8").encode(message)); } } } //处理接入状态操作 private void acceptOperator(ServerSocketChannel serverSocketChannel, Selector selector) throws IOException { //1 接入状态，创建socketChannel SocketChannel socketChannel = serverSocketChannel.accept(); //2 把socketChannel设置非阻塞模式 socketChannel.configureBlocking(false); //3 把channel注册到selector选择器上，监听可读状态 socketChannel.register(selector,SelectionKey.OP_READ); //4 客户端回复信息 socketChannel.write(Charset.forName("UTF-8") .encode("欢迎进入聊天室，请注意隐私安全")); } //启动主方法 public static void main(String[] args) { try { new ChatServer().startServer(); } catch (IOException e) { e.printStackTrace(); } } }