Java實現簡單的HTTP服務器代碼

import java.net.;
import java.nio.ByteBuffer;
import java.nio.channels.;
import java.nio.charset.;
import java.util.concurrent.;
import java.io.*;

public class SimpleHttpServer {
    private int port = 80;
    private ServerSocketChannel serverSocketChannel = null;
    private ExecutorService executorService;
    private static final int POOL_MULTIPLE = 4;

public SimpleHttpServer() throws IOException {
    executorService = Executors.newFixedThreadPool(Runtime.getRuntime()
            .availableProcessors() * POOL_MULTIPLE);
    serverSocketChannel = ServerSocketChannel.open();
    serverSocketChannel.socket().setReuseAddress(true);
    serverSocketChannel.socket().bind(new InetSocketAddress(port));
}

public void service() {
    while (true) {
        SocketChannel socketChannel = null;
        try {
            socketChannel = serverSocketChannel.accept();
            executorService.execute(new Handler(socketChannel));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

public static void main(String[] args) throws IOException {
    new SimpleHttpServer().service();
}


}
class Handler implements Runnable {
    private SocketChannel socketChannel;
    public Handler(SocketChannel socketChannel) {
        this.socketChannel = socketChannel;
    }

@Override
public void run() {
    handle(socketChannel);
}

private void handle(SocketChannel socketChannel) {
    try {
        Socket socket = socketChannel.socket();
        System.out
                .println(socket.getInetAddress() + ":" + socket.getPort());
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        socketChannel.read(buffer);
        buffer.flip();
        String request = decode(buffer);
        StringBuffer sb = new StringBuffer("HTTP/1.1 200 OK\r\n");
        sb.append("Content-Type:text/html\r\n\r\n");
        socketChannel.write(encode(sb.toString()));
        FileInputStream in = null;
        String firstLineOfRequest = request.substring(0,
                request.indexOf("\r\n"));
        if (firstLineOfRequest.indexOf("login.htm") != -1)
            in = new FileInputStream("login.htm");
        else
            in = new FileInputStream("hello.htm");
        FileChannel fileChannel = in.getChannel();
        fileChannel.transferTo(0, fileChannel.size(), socketChannel);
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            if (socketChannel != null)
                socketChannel.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

private Charset charset = Charset.forName("GBK");

private ByteBuffer encode(String string) {
    return ByteBuffer.allocate(string.length() * 2).get(
            string.getBytes(charset));
}

private String decode(ByteBuffer buffer) {
    byte[] source = new byte[buffer.position() + 1];
    buffer.put(source);
    return new String(source, charset);
}

}
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