Netty入门--AIO
AIO也就是NIO2.0，是Java1.7提供的新异步非阻塞I/O
NIO2.0的异步套接字通道是真正的异步非阻塞I/O，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。
下面是demo
package com.hueason.netty.n1.aio;
/**
* Created by Administrator on 2017/4/20.
*/
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, "AIO-AsyncTimeServerHandler-001").start();
}
}
package com.hueason.netty.n1.aio;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.channels.AsynchronousServerSocketChannel;
import java.util.concurrent.CountDownLatch;
/**
* Created by Administrator on 2017/4/20.
*/
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) {
e.printStackTrace();
}
}
@Override
public void run() {
latch = new CountDownLatch(1);
doAccept();
try {
latch.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
private void doAccept() {
asynchronousServerSocketChannel.accept(this,new AcceptCompletionHandler());
}
}
package com.hueason.netty.n1.aio;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
/**
* Created by Administrator on 2017/4/20.
*/
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();
}
}
package com.hueason.netty.n1.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;
/**
* Created by Administrator on 2017/4/20.
*/
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) {
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) {
//如果没有发送完整，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) {
e.printStackTrace();
}
}
});
}
}
@Override
public void failed(Throwable exc, ByteBuffer attachment) {
try {
this.channel.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
客户端
package com.hueason.netty.n1.aio;
/**
* Created by Administrator on 2017/4/20.
*/
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-AayncTimeClientHandler-001").start();
}
}
package com.hueason.netty.n1.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;
/**
* Created by Administrator on 2017/4/20.
*/
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.port = port;
this.host = host;
try {
client = AsynchronousSocketChannel.open();
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void run() {
latch = new CountDownLatch(1);
client.connect(new InetSocketAddress(host, port), this, this);
try {
latch.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
try {
client.close();
} catch (IOException e) {
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) {
e.printStackTrace();
}
}
@Override
public void failed(Throwable exc, ByteBuffer attachment) {
try {
client.close();
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
}
@Override
public void failed(Throwable exc, ByteBuffer attachment) {
try {
client.close();
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
@Override
public void failed(Throwable exc, AsyncTimeClientHandler attachment) {
exc.printStackTrace();
try {
client.close();
latch.countDown();
} catch (IOException e) {
e.printStackTrace();
}
}
}
只是简单的demo，用来描述AIO的基本用法。
NIO2.0中不需要像NIO那样创建一个独立的I/O线程来处理读写操作。
NIO2.0对于AsynchronousServerSocketChannel和AsynchronousSocketChannel，都是由JDK底层的线程池负责回调并驱动读写操作，相比于NIO编程更为简单。