将套接字输入流从另一个套接字重定向到输出流

Question

我试图在我的应用程序中收听 HTTP 对网站的请求。 我的应用程序用于从 Socket1 的输入流中提取一些数据并将其转发到另一个 socket2（连接到实际 web 服务器的客户端 socket2）的 output stream 。 网络服务器应该分析（-> Inputstream2），我想将它传递回socket1的输出流1。 在这个星座中，真正的网络服务器正在收到请求，但我没有收到答案。 我读到，我必须关闭一个套接字的 output stream 才能开始读取输入流，所以我也尝试了 socket.shutdownOutput() 但它仍然无法正常工作。

我会给予任何帮助

private static void runHttpListener(Boolean simulate){
    try {
        ServerSocket server = new ServerSocket(PORT_HTTP_REQUEST);
        System.out.println("HTTP listener active on Port "+PORT_HTTP_REQUEST);
        boolean keepAlive = true;
        while (keepAlive) {               
            //Empfangen und auslesen
            Socket socketReceivingProxy = server.accept();  
            System.out.println("HTTP-Listener: Accepted client connection");              
            InputStream proxyInputStream = socketReceivingProxy.getInputStream();
            OutputStream proxyOutputStream = socketReceivingProxy.getOutputStream();
            //TODO: extract information from stream
            
            //forward
            InputStream result = sendHttpRequestToDestination(proxyInputStream, simulate);
            result.transferTo(proxyOutputStream);
            

            result.close();
            proxyOutputStream.close();
            socketReceivingProxy.close();
        }
        server.close();  
        System.out.println("HTTP listener closed");    
    } catch (Exception e) {
        e.printStackTrace();
    }

我的转发方法非常简单，但实际上并不起作用：

private static InputStream sendHttpRequestToDestination(InputStream incomingRequest, Boolean simulate){
    try{
        
        Socket socketForwardingWebapp = new Socket(simulate?URL_WEB_SERVER_SIMULATION:URL_WEB_SERVER, 
            simulate?PORT_WEB_SERVER_SIMULATION:PORT_WEB_SERVER);
        System.out.println("HTTP-Forwarding: Created socket "+socketForwardingWebapp.getInetAddress()+":"+socketForwardingWebapp.getPort());  
        InputStream webappInputStream = socketForwardingWebapp.getInputStream();
        OutputStream outputStream = socketForwardingWebapp.getOutputStream();
        if(incomingRequest.available()>0){
            System.out.println("Incoming Request can be forwarded");
            long bytesTransfered = incomingRequest.transferTo(outputStream);
            System.out.print("stream copied");
            socketForwardingWebapp.shutdownOutput();
            System.out.println("Bytes forwareded: "+bytesTransfered);
        }
        return webappInputStream;
    }catch(Exception exc){
        exc.printStackTrace();
    }
    return null;
}

Answer 1

我使用线程解决了这个问题。 这是有效的：

    private static Thread inputStreamToOutputStream(InputStream inputStream, OutputStream outputStream){
    Thread t = new Thread(() -> {
        long transferedBytes = 0;
        try {
            transferedBytes = inputStream.transferTo(outputStream);
            inputStream.close();
            outputStream.close();
            System.out.println("StreamTransformer: Bytes forwareded: "+transferedBytes);
        } catch (IOException e) {
            System.out.println("StreamTransformer: Error accoured while transforming");
        }
    });
    t.start();
    return t;
}

像这样使用这种新方法：

private static Thread sendHttpRequestToDestination(InputStream incomingRequest, OutputStream outgoingAnswer, Boolean simulate){
    Thread t = new Thread(){
        public void run(){
            try{  
                Socket socketForwardingWebapp = new Socket(simulate?URL_WEB_SERVER_SIMULATION:URL_WEB_SERVER, 
                    simulate?PORT_WEB_SERVER_SIMULATION:PORT_WEB_SERVER);
                System.out.println("HTTP-Forwarding: Created socket "+socketForwardingWebapp.getInetAddress()+":"+socketForwardingWebapp.getPort());  
                InputStream webappInputStream = socketForwardingWebapp.getInputStream();
                OutputStream outputStream = socketForwardingWebapp.getOutputStream();
                if(incomingRequest.available()>0){
                    System.out.println("HTTP-Forwarding: Incoming Request can be forwarded");
                    Thread send = inputStreamToOutputStream(incomingRequest, outputStream);
                    Thread receive = inputStreamToOutputStream(webappInputStream, outgoingAnswer);
                    send.join();
                    System.out.println("HTTP-Forwarding: successfuly sent");
                    receive.join();
                    System.out.println("HTTP-Forwarding: successfuly received");
                }
                socketForwardingWebapp.close();
            }catch(Exception exc){
                exc.printStackTrace();
            }
        }
    };
    t.start();
    return t;
}