server端
package com.example.demo.socket;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
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;
import java.util.Set;
public class NioServer {
public static void main(String[] args) throws IOException {
server(8888);
}
public static void server(int port) throws IOException {
//1、打开服务器套接字通道
ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
//2、设定为非阻塞、调整此通道的阻塞模式。
serverSocketChannel.configureBlocking(false);
//3、创建一个与此通道关联的服务器套接字。
ServerSocket serverSocket = serverSocketChannel.socket();
//4、此类实现 ip 套接字地址 (ip 地址 + 端口号)
InetSocketAddress address = new InetSocketAddress(port);
//5、将服务器绑定到选定的套接字地址
serverSocket.bind(address);
//6、打开Selector来处理Channel
Selector selector = Selector.open();
//7、将ServerSocket注册到Selector已接受连接，注册会判断是否为非阻塞模式
SelectionKey selectionKey = serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
ByteBuffer readBuff = ByteBuffer.allocate(1024);
final ByteBuffer msg = ByteBuffer.wrap("Hi!".getBytes());
while (true){
try {
//等到需要处理的新事件：阻塞将一直持续到下一个传入事件
selector.select();
}catch (IOException e){
e.printStackTrace();
break;
}
//获取所有接收事件的SelectionKey实例
Set<SelectionKey> readykeys = selector.selectedKeys();
Iterator<SelectionKey> iterator = readykeys.iterator();
while(iterator.hasNext()){
SelectionKey key = iterator.next();
iterator.remove();
try {
//检查事件是否是一个新的已经就绪可以被接受的连接
if (key.isAcceptable()){
//channel：返回为其创建此键的通道。 即使在取消密钥后, 此方法仍将继续返回通道。
ServerSocketChannel server = (ServerSocketChannel)key.channel();
//可选择的通道, 用于面向流的连接插槽。
SocketChannel client = server.accept();
//设定为非阻塞
client.configureBlocking(false);
//接受客户端，并将它注册到选择器，并添加附件
client.register(selector,SelectionKey.OP_WRITE | SelectionKey.OP_READ,msg.duplicate());
System.out.println("Accepted connection from " + client);
}
//检查套接字是否已经准备好读数据
if (key.isReadable()){
SocketChannel client = (SocketChannel)key.channel();
readBuff.clear();
int read = client.read(readBuff);
readBuff.flip();
System.out.println("server收到: "+new String(readBuff.array(),0,read));
//将此键的兴趣集设置为给定的值。 OP_WRITE
key.interestOps(SelectionKey.OP_WRITE);
}
//检查套接字是否已经准备好写数据
if (key.isWritable()){
SocketChannel client = (SocketChannel)key.channel();
//attachment : 检索当前附件
ByteBuffer buffer = (ByteBuffer)key.attachment();
buffer.rewind();
client.write(buffer);
//将此键的兴趣集设置为给定的值。 OP_READ
key.interestOps(SelectionKey.OP_READ);
}
}catch (IOException e){
//发生异常从selector取消注册,防止一直报错
key.cancel();
e.printStackTrace();
}
}
}
}
}
client端
package com.example.demo.socket;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;
public class WebClient {
public static void main(String[] args) throws IOException {
try {
SocketChannel socketChannel = SocketChannel.open();
socketChannel.connect(new InetSocketAddress("127.0.0.1",8888));
ByteBuffer writeBuffer = ByteBuffer.allocate(32);
ByteBuffer readBuffer = ByteBuffer.allocate(32);
writeBuffer.put("helloWebClient ".getBytes());
writeBuffer.flip();
while (true){
writeBuffer.rewind();
socketChannel.write(writeBuffer);
readBuffer.clear();
int read = socketChannel.read(readBuffer);
readBuffer.flip();
System.out.println("client收到: "+new String(readBuffer.array(),0,read));
Thread.sleep(2000L);
//关闭
//socketChannel.close();
}
}catch (IOException e){
e.printStackTrace();
} catch (InterruptedException e) {
}
}
}
