如何使用Java Socket监听80端口

Question

I have a server whose port 80 is for occupied by HTTP transactions. I wanted to see the traffic in that port and I tried to use a socket program to listen to that port.

public Server(int serverPort) throws IOException {  
    super(serverPort);  
    try {  
        while (true) {  
            Socket socket = accept();  
            new ServerThread(socket);  
        }  
    } catch (IOException e) {  
        e.printStackTrace();  
    } finally {  
        close();
    }  
}  

// inner-class ServerThread  
class ServerThread extends Thread {  
    private Socket socket;  
    private BufferedReader in;  
    private PrintWriter out;  

    // Ready to conversation  
    public ServerThread(Socket s) throws IOException {  
        this.socket = s;  
        in = new BufferedReader(new InputStreamReader(socket  
                .getInputStream(), "UTF-8"));  
        out = new PrintWriter(socket.getOutputStream(), true);  
        start();  
    }  

    // Execute conversation  
    public void run() {  
        try {  

            // Communicate with client until "bye " received.  
            while (true) {  
                String line = in.readLine();  
                if (line == null || "".equals(line.trim())) {
                    break;  
                }  
                System.out.println("Received   message: " + line);  
                out.println(line);  
                out.flush();  
            }  

            out.close();  
            in.close();  
            socket.close();  

        } catch (IOException e) {  
            e.printStackTrace();  
        }  
    }  

}  

public static void main(String[] args) throws IOException {  
    new Server(80);  
} 

However, when I run that java application, it showed a BindException: Address already in use.

So what should I do to my code and make it listen to port 80, or are there any other ways to listen to that port in Java?

Answer 1

If I understand you correctly you are trying to sniff the packets that are being passed to your server. If that is the case there are some answers in this post.

Answer 2

What Server are you running it on?

it all depends on the type of server you're working on. Tomcat for example has the type of port it's running off of in the Server.xml file.

Answer 3

In Windows you can run your program by administrator. In Linux using root user.