nio reactor模式的代码
时间: 2023-09-03 22:27:19 浏览: 94
### 回答1:
我可以给你一些关于NIO Reactor模式的代码示例: public class Reactor implements Runnable {
final Selector selector;
final ServerSocketChannel serverSocket; Reactor(int port) throws IOException {
selector = Selector.open();
serverSocket = ServerSocketChannel.open();
serverSocket.socket().bind(new InetSocketAddress(port));
serverSocket.configureBlocking(false); // 将 ServerSocketChannel 注册到 Selector,并声明它只对连接事件感兴趣
SelectionKey sk = serverSocket.register(selector, SelectionKey.OP_ACCEPT);
sk.attach(new Acceptor());
} public void run() {
try {
while (!Thread.interrupted()) {
selector.select();
Set selected = selector.selectedKeys();
Iterator it = selected.iterator();
while (it.hasNext())
dispatch((SelectionKey) (it.next()));
selected.clear();
}
} catch (IOException ex) { /* ... */ }
} void dispatch(SelectionKey k) {
Runnable r = (Runnable) (k.attachment());
// 调用之前注册的 callback 对象
if (r != null)
r.run();
} // inner class
class Acceptor implements Runnable {
public void run() {
try {
SocketChannel c = serverSocket.accept();
if (c != null)
new Handler(selector, c);
} catch (IOException ex) { /* ... */ }
}
}
}
### 回答2:
NIO(New I/O)是Java提供的一种非阻塞I/O操作的API,而Reactor模式是一种常见的基于事件驱动的设计模式,用于实现高性能的网络通信。在使用NIO API时,可以结合Reactor模式来编写代码。
首先,创建一个Server类,实现服务端的功能。该类包含一个Selector对象,用于监听事件。在构造方法中,创建Selector对象,并将其与特定的网络地址进行绑定。然后,将监听事件交给Reactor类进行处理。
```java
public class Server {
private Selector selector;
public Server(int port) throws IOException {
selector = Selector.open();
ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
serverSocketChannel.bind(new InetSocketAddress(port));
serverSocketChannel.configureBlocking(false);
serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
System.out.println("Server started on port " + port);
}
public void start() throws IOException {
Reactor reactor = new Reactor(selector);
reactor.run();
}
}
```
接下来,创建Reactor类,实现反应堆(Reactor)的功能。该类负责监听事件并分发到对应的处理器进行处理。
```java
public class Reactor implements Runnable {
private Selector selector;
public Reactor(Selector selector) {
this.selector = selector;
}
@Override
public void run() {
try {
while (true) {
selector.select();
Set<SelectionKey> selectedKeys = selector.selectedKeys();
Iterator<SelectionKey> iterator = selectedKeys.iterator();
while (iterator.hasNext()) {
SelectionKey key = iterator.next();
iterator.remove();
if (key.isAcceptable()) {
// 处理连接事件
handleAcceptable(key);
} else if (key.isReadable()) {
// 处理读取事件
handleReadable(key);
} else if (key.isWritable()) {
// 处理写入事件
handleWritable(key);
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
private void handleAcceptable(SelectionKey key) throws IOException {
ServerSocketChannel serverSocketChannel = (ServerSocketChannel) key.channel();
SocketChannel socketChannel = serverSocketChannel.accept();
socketChannel.configureBlocking(false);
socketChannel.register(selector, SelectionKey.OP_READ);
}
private void handleReadable(SelectionKey key) throws IOException {
SocketChannel socketChannel = (SocketChannel) key.channel();
// 读取数据并进行处理
// ...
socketChannel.register(selector, SelectionKey.OP_WRITE);
}
private void handleWritable(SelectionKey key) throws IOException {
SocketChannel socketChannel = (SocketChannel) key.channel();
// 写入数据并进行处理
// ...
socketChannel.register(selector, SelectionKey.OP_READ);
}
}
```
通过以上代码,实现了基于NIO的Reactor模式。在Server类中,创建了一个Selector对象,并将其与ServerSocketChannel进行绑定。然后,通过Reactor类监听事件并分发到处理器。处理器根据不同的事件类型,执行对应的操作。在处理完一个事件后,将对应的通道再次注册到Selector对象中,继续监听下一个事件。这样可以实现非阻塞的网络通信。
### 回答3:
NIO(New Input/Output)是Java提供的一种非阻塞式IO操作的方式,Reactor模式是一种事件驱动的设计模式,结合两者可以实现高效的网络编程。
下面是一个简单的基于NIO的Reactor模式的代码示例:
```java
import java.io.IOException;
import java.net.InetSocketAddress;
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 ReactorServer {
public static void main(String[] args) throws IOException {
Selector selector = Selector.open();
ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
serverSocketChannel.socket().bind(new InetSocketAddress(8080));
serverSocketChannel.configureBlocking(false);
serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
while (true) {
selector.select();
Set selectedKeys = selector.selectedKeys();
Iterator<SelectionKey> iterator = selectedKeys.iterator();
while (iterator.hasNext()) {
SelectionKey key = iterator.next();
if (key.isAcceptable()) {
ServerSocketChannel serverChannel = (ServerSocketChannel) key.channel();
SocketChannel clientChannel = serverChannel.accept();
clientChannel.configureBlocking(false);
clientChannel.register(selector, SelectionKey.OP_READ);
}
if (key.isReadable()) {
SocketChannel clientChannel = (SocketChannel) key.channel();
ByteBuffer buffer = ByteBuffer.allocate(1024);
clientChannel.read(buffer);
// 处理读取到的数据
String receivedData = new String(buffer.array()).trim();
System.out.println("Received data: " + receivedData);
}
iterator.remove();
}
}
}
}
```
这段代码通过NIO提供的Selector轮询监听事件,当有新的连接请求到来时,注册到Selector上,并设置为可读事件。当有数据可读时,通过ByteBuffer进行读取,然后可以处理具体的业务逻辑。
该代码使用NIO提供的API实现了一个简单的Reactor模式的服务器,使得服务器可以同时处理多个连接,并实现了非阻塞的网络IO操作。这种事件驱动的设计模式可以提高性能和可扩展性,使得服务器能够高效地处理并发请求。