用JAVA实现一个简单地Http服务器

    import java.io.FileInputStream;        import java.io.IOException;        import java.net.InetSocketAddress;        import java.net.Socket;        import java.nio.ByteBuffer;        import java.nio.CharBuffer;        import java.nio.channels.FileChannel;        import java.nio.channels.ServerSocketChannel;        import java.nio.channels.SocketChannel;        import java.nio.charset.Charset;        import java.util.concurrent.ExecutorService;        import java.util.concurrent.Executors;                public class SimpleHttpServer {                        private int port=8080;              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));                System.out.println("ddd");              }                      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;              }              public void run(){                handle(socketChannel);              }                      public void handle(SocketChannel socketChannel){                try {                    Socket socket=socketChannel.socket();                    System.out.println("ddd" +                    socket.getInetAddress() + ":" +socket.getPort());                             ByteBuffer buffer=ByteBuffer.allocate(1024);                     socketChannel.read(buffer);                     buffer.flip();                     String request=decode(buffer);                     System.out.print(request);                               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;                                          String firstLineOfRequest=request.substring(0,request.indexOf("\r\n"));                     if(firstLineOfRequest.indexOf("login.htm")!=-1)                        in=new FileInputStream("/Users/tokou/Documents/post.html");                     else                        in=new FileInputStream("/Users/tokou/Documents/post.html");                             FileChannel fileChannel=in.getChannel();                     fileChannel.transferTo(0,fileChannel.size(),socketChannel);                     fileChannel.close();                  }catch (Exception e) {                     e.printStackTrace();                  }finally {                     try{                       if(socketChannel!=null)socketChannel.close();                     }catch (IOException e) {e.printStackTrace();}                  }              }              private Charset charset=Charset.forName("GBK");              public String decode(ByteBuffer buffer){                  CharBuffer charBuffer= charset.decode(buffer);                return charBuffer.toString();              }              public ByteBuffer encode(String str){                  return charset.encode(str);              }             }        }