Java并发编程疑难：非阻塞IO的实现案例。

原创 Myth丶恋晨 2024-09-19 13:42 11阅读 0赞

在Java中，非阻塞I/O（Non-blocking Input/Output）主要通过NIO（New IO）API来实现。以下是一个简单的非阻塞I/O的实现案例，这里我们使用Java NIO的通道（Channel）和选择器（Selector）。

```java
import java.io.IOException;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;

public class NonBlockingServer {

private ServerSocketChannel serverSocketChannel;
    private Selector selector;

public NonBlockingServer(int port) throws IOException {
        serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.configureBlocking(false);
        serverSocketChannel.socket().bind(new InetSocketAddress(port)));
        selector = Selector.open();
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT));
    }

public void acceptClients() throws IOException {
        while (true) {
            selector.select();
            Iterator<SelectionKey> iterator = selector.selectedKeys().iterator();
            while (iterator.hasNext()) {
                SelectionKey key = iterator.next();
                if (!key.isAcceptable()) {
                    // handle other operations like reading/writing
                    continue;
                }

SocketChannel socketChannel = serverSocketChannel.channel().accept(key);
                if (socketChannel != null) {
                    // register the new socket for further operations
                    socketChannel.register(selector, SelectionKey.OP_READ));
                }
            }
        }
    }

public void close() throws IOException {
        selector.close();
        serverSocketChannel.close();
    }
}
```

这个例子创建了一个非阻塞的服务器，它接受客户端连接并为每个新连接注册一个读取操作。当服务器关闭时，所有相关的通道和选择器都将被关闭。