04-netty基础-AIO编程
1.JDK1.7升级了NIO类库，升级后的NIO类库被称为NIO 2.0，Java 正式提供了异步文件I/O操作，同时提供了与UNIX网络编程实践驱动I/O对应的AIO。
2.NIO 2.0引入了新的异步通道的概念，并提供了异步文件通道和异步套接字通道的实现，异步通道提供两种方式获取通道结果。
一是通过java.util.concurrent.Future 类来表示异步操作的结果。
二是在执行异步操作的时候传入一个java.nio.channels。
CompletionHandler接口的实现类作为操作完成的回调。
NIO 2.0的异步套接字通道是真正的异步非阻塞I/O，对应于UNIX网络编程实践驱动I/O（AIO）。它不需要通过多路复用器（Selector）对注册的通道进行轮询操作即可实现异步读写，从而简化了NIO 的编程模型。
3.AIO TimeServer.java 源码：
package com.pats.file.aio;
public class TimeServer {
public static void main(String[] args) {
int port = 8080;
if(args != null&& args.length > 0 ) {
port = Integer.valueOf(args[0]);
}
AsyncTimeServerHandler timeServer = new AsyncTimeServerHandler(port);
new Thread(timeServer,"NIO-MultiplexerTimeServer-001").start();
}
}
AsyncTimeServerHandler.java
package com.pats.file.aio;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.channels.AsynchronousServerSocketChannel;
import java.util.concurrent.CountDownLatch;
public class AsyncTimeServerHandler implements Runnable{
private int port;
CountDownLatch latch;
AsynchronousServerSocketChannel asynchronousServerSocketChannel;
public AsyncTimeServerHandler(int port) {
this.port = port;
try {
asynchronousServerSocketChannel = AsynchronousServerSocketChannel.open();
asynchronousServerSocketChannel.bind(new InetSocketAddress(port));
System.out.println("The time server is start in port : "+ port);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public void run() {
latch = new CountDownLatch(1);
doAccept();
try {
latch.await();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private void doAccept() {
asynchronousServerSocketChannel.accept(this, new AcceptCompletionHandler());
}
}
AcceptCompletionHandler.java
package com.pats.file.aio;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
public class AcceptCompletionHandler implements CompletionHandler {
@Override
public void completed(AsynchronousSocketChannel result, AsyncTimeServerHandler attachment) {
attachment.asynchronousServerSocketChannel.accept(attachment,this);
ByteBuffer buffer = ByteBuffer.allocate(1024);
result.read(buffer,buffer,new ReadCompletionHandler(result));
}
@Override
public void failed(Throwable exc, AsyncTimeServerHandler attachment) {
exc.printStackTrace();
attachment.latch.countDown();
}
}
4.AIO创建 TimeClient.java 源码：
package com.pats.file.aio;
public class TimeClient {
public static void main(String[] args) {
int port = 8080;
if(args!=null && args.length > 0) {
port = Integer.valueOf(args[0]);
}
new Thread(new AsyncTimeClientHandler("127.0.0.1", port),"Aio-AsyncTimeClientHandler-001").start();
}
}AsyncTimeClientHandler.java
package com.pats.file.aio;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
import java.util.concurrent.CountDownLatch;
public class AsyncTimeClientHandler implements CompletionHandler,Runnable {
private AsynchronousSocketChannel client;
private String host;
private int port;
private CountDownLatch latch;
public AsyncTimeClientHandler(String host, int port) {
this.host = host;
this.port = port;
try {
client = AsynchronousSocketChannel.open();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public void run() {
latch = new CountDownLatch(1);
client.connect(new InetSocketAddress(host, port),this,this);
try {
latch.await();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
client.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public void completed(Void result, AsyncTimeClientHandler attachment) {
byte[] req = "QUERY TIME ORDER".getBytes();
ByteBuffer writeBuffer = ByteBuffer.allocate(req.length);
writeBuffer.put(req);
writeBuffer.flip();
client.write(writeBuffer, writeBuffer, new CompletionHandler() {
@Override
public void completed(Integer result, ByteBuffer buffer) {
if(buffer.hasRemaining()) {
client.write(buffer,buffer,this);
}else {
ByteBuffer readBuffer = ByteBuffer.allocate(1024);
client.read(readBuffer,readBuffer,new CompletionHandler() {
@Override
public void completed(Integer result, ByteBuffer buffer) {
buffer.flip();
byte[] bytes = new byte[buffer.remaining()];
buffer.get(bytes);
String body;
try {
body = new String(bytes,"UTF-8");
System.out.println("Now is : "+ body);
latch.countDown();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public void failed(Throwable exc, ByteBuffer attachment) {
try {
client.close();
latch.countDown();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
}
@Override
public void failed(Throwable exc, ByteBuffer buffer) {
try {
client.close();
latch.countDown();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
@Override
public void failed(Throwable exc, AsyncTimeClientHandler attachment) {
exc.printStackTrace();
try {
client.close();
latch.countDown();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
ReadCompletionHandler.java
package com.pats.file.aio;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
import java.util.Date;
public class ReadCompletionHandler implements CompletionHandler {
private AsynchronousSocketChannel channel;
public ReadCompletionHandler( AsynchronousSocketChannel channel) {
if(this.channel == null)
this.channel = channel;
}
@Override
public void completed(Integer result, ByteBuffer attachment) {
attachment.flip();
byte[] body = new byte[attachment.remaining()];
attachment.get(body);
try {
String req = new String(body,"UTF-8");
System.out.println("The time server receive order : "+req);
String currentTime = "QUERY TIME ORDER".equalsIgnoreCase(req)? new Date(System.currentTimeMillis()).toString() : "BAD ORDER";
doWrite(currentTime);
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private void doWrite(String currentTime) {
if(currentTime!=null && currentTime.trim().length() > 0) {
byte[] bytes = (currentTime).getBytes();
ByteBuffer writeBuffer = ByteBuffer.allocate(bytes.length);
writeBuffer.put(bytes);
writeBuffer.flip();
channel.write(writeBuffer,writeBuffer,new CompletionHandler() {
@Override
public void completed(Integer result, ByteBuffer buffer) {
//：如果没有发送完继续发送
if(buffer.hasRemaining()) {
channel.write(buffer,buffer,this);
}
}
@Override
public void failed(Throwable exc, ByteBuffer attachment) {
try {
channel.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
}
@Override
public void failed(Throwable exc, ByteBuffer attachment) {
try {
this.channel.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
5.运行程序：
客户端：
服务端：
