声明
该系列文章由书籍《Netty权威指南》第二版整理而来。只为记录学习笔记。
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[TOC]
时间服务器--AIO
服务端代码
服务端主程序
public class TimeServer {
public static void main(String[] args) throws IOException {
int port = 1234;
new Thread(new TimeServerHandler(port)).start();
}
}
服务端处理程序
public class TimeServerHandler implements Runnable {
private int port;
private CountDownLatch latch;
private AsynchronousServerSocketChannel asynchronousServerSocketChannel;
public TimeServerHandler(int port) {
this.port = port;
try {
this.asynchronousServerSocketChannel = AsynchronousServerSocketChannel.open();
this.asynchronousServerSocketChannel.bind(new InetSocketAddress(this.port));
System.out.println("The time server is listening in port : " + this.port);
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void run() {
this.latch = new CountDownLatch(1);
doAccept();
try {
this.latch.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
private void doAccept() {
this.asynchronousServerSocketChannel.accept(this,
new CompletionHandler<AsynchronousSocketChannel, TimeServerHandler>() {
@Override
public void completed(AsynchronousSocketChannel result, TimeServerHandler attachment) {
attachment.asynchronousServerSocketChannel.accept(attachment, this);
ByteBuffer buffer = ByteBuffer.allocate(1024);
result.read(buffer, buffer, new TimeServerReadCompletionHandler(result));
}
@Override
public void failed(Throwable exc, TimeServerHandler attachment) {
exc.printStackTrace();
attachment.latch.countDown();
}
});
}
// public AsynchronousServerSocketChannel getAsynchronousServerSocketChannel() {
// return asynchronousServerSocketChannel;
// }
//
// public void setAsynchronousServerSocketChannel(AsynchronousServerSocketChannel asynchronousServerSocketChannel) {
// this.asynchronousServerSocketChannel = asynchronousServerSocketChannel;
// }
//
// public CountDownLatch getLatch() {
// return latch;
// }
//
// public void setLatch(CountDownLatch latch) {
// this.latch = latch;
// }
}
服务端处理程序
public class TimeServerReadCompletionHandler implements CompletionHandler<Integer, ByteBuffer> {
private AsynchronousSocketChannel channel;
private DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
public TimeServerReadCompletionHandler(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("request msg is : " + req);
doWrite(this.df.format(new Date()));
} 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<Integer, ByteBuffer>() {
@Override
public void completed(Integer result, ByteBuffer buffer) {
if (buffer.hasRemaining())
channel.write(buffer, buffer, this);
}
@Override
public void failed(Throwable exc, ByteBuffer attachment) {
try {
channel.close();
} catch (IOException e) {
}
}
});
}
}
@Override
public void failed(Throwable exc, ByteBuffer attachment) {
try {
this.channel.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
客户端代码
客户端主程序
public class TimeClient {
public static void main(String[] args) {
int port = 1234;
new Thread(new TimeClientHandler("127.0.0.1", port)).start();
}
}
客户端处理类
public class TimeClientHandler implements CompletionHandler<Void, TimeClientHandler>, Runnable {
private AsynchronousSocketChannel asc;
private String host;
private int port;
private CountDownLatch latch;
public TimeClientHandler(String host, int port) {
this.host = host;
this.port = port;
try {
this.asc = AsynchronousSocketChannel.open();
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void run() {
latch = new CountDownLatch(1);
asc.connect(new InetSocketAddress(host, port), this, this);
try {
latch.await();
} catch (InterruptedException e1) {
e1.printStackTrace();
}
try {
asc.close();
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void completed(Void result, TimeClientHandler attachment) {
byte[] req = "Hi Server !".getBytes();
ByteBuffer writeBuffer = ByteBuffer.allocate(req.length);
writeBuffer.put(req);
writeBuffer.flip();
asc.write(writeBuffer, writeBuffer, new CompletionHandler<Integer, ByteBuffer>() {
@Override
public void completed(Integer result, ByteBuffer buffer) {
if (buffer.hasRemaining()) {
asc.write(buffer, buffer, this);
} else {
ByteBuffer readBuffer = ByteBuffer.allocate(1024);
asc.read(readBuffer, readBuffer, new CompletionHandler<Integer, ByteBuffer>() {
@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 {
asc.close();
latch.countDown();
} catch (IOException e) {
}
}
});
}
}
@Override
public void failed(Throwable exc, ByteBuffer attachment) {
try {
asc.close();
latch.countDown();
} catch (IOException e) {
}
}
});
}
@Override
public void failed(Throwable exc, TimeClientHandler attachment) {
exc.printStackTrace();
try {
asc.close();
latch.countDown();
} catch (IOException e) {
e.printStackTrace();
}
}
}
总结
这种AIO模型有如下特点:
- 代码复杂
- 调试困难
参考资料: 《Netty权威指南》第二版
