从套接字读取时如何检测客户端何时完成发送请求？ [英] While reading from socket how to detect when the client is done sending the request?

问题描述

我现在正在编写一个http服务器，我在从套接字读取时遇到问题。
我的问题是来自客户端的 inputStream 永远不会结束，它一直在读取，直到客户端关闭。
我知道客户端在发送http请求后没有立即关闭与服务器的连接。
当客户端发送了所有请求数据（即标题+正文）时，如何退出 while循环。

I am now writing a http server and I am having problem with reading from a socket. My problem is that the inputStream from the client never ends and it keeps reading until the client is closed. I know that the client doesn't close the connection with the server immediately after sending the http request. How can I quit the while loop when client has sent all the request data (i.e. headers + body).

while (in.hasNextLine()) {
    String line = in.nextLine();

    if (line.equals("")){ // last line of request header is blank
        break; // quit while loop when last line of header is reached
    } else {
        request = request + line + "\n";
    }
}

在阅读了你们的评论和回答后，这是我想出了什么，

After reading comments and answer from you guys, this is what I came up with,

     is = incoming.getInputStream();
            os = incoming.getOutputStream();
            in = new Scanner(is);
            out = new DataOutputStream(os);

            RequestHandler rh = new RequestHandler();
            int length = 0;
            while (in.hasNextLine()) {
                String line = in.nextLine();
                if (line.equals("")) { // last line of request message
                                        // header is a
                                        // blank line
                    break; // quit while loop when last line of header is
                            // reached
                }

                if (line.startsWith("Content-Length: ")) { // get the
                                                            // content-length
                    int index = line.indexOf(':') + 1;
                    String len = line.substring(index).trim();
                    length = Integer.parseInt(len);
                }

                request = request + line + "\n";
            }

             byte[] body = new byte[length];
             int i = 0;
             while (i < length) {
             byte b = in.nextByte();
             body[i] = b;
             i++;
             }

但是，我仍然不知道按字节读取数据。我可以编写我的代码来读取-1，但是当没有EOF且客户端没有关闭连接时仍然卡住。

but, I still don't get it about reading by bytes. I can write my code to read until -1, but still stuck when there is no EOF and client is not closing connection.

推荐答案

我已经知道了:)谢谢大家的评论和答案...

I've got it :) Thank you guys for comments and answers...

     is = incoming.getInputStream(); // initiating inputStream
            os = incoming.getOutputStream(); // initiating outputStream

            in = new BufferedReader(new InputStreamReader(is)); // initiating
                                                                // bufferReader
            out = new DataOutputStream(os); // initiating DataOutputSteream

            RequestHandler rh = new RequestHandler(); // create a
                                                        // requestHandler
                                                        // object

            String line;
            while ((line = in.readLine()) != null) {
                if (line.equals("")) { // last line of request message
                                        // header is a
                                        // blank line (\r\n\r\n)
                    break; // quit while loop when last line of header is
                            // reached
                }

                // checking line if it has information about Content-Length
                // weather it has message body or not
                if (line.startsWith("Content-Length: ")) { // get the
                                                            // content-length
                    int index = line.indexOf(':') + 1;
                    String len = line.substring(index).trim();
                    length = Integer.parseInt(len);
                }

                request.append(line + "\n"); // append the request
            } // end of while to read headers

            // if there is Message body, go in to this loop
            if (length > 0) {
                int read;
                while ((read = in.read()) != -1) {
                    body.append((char) read);
                    if (body.length() == length)
                        break;
                }
            }

            request.append(body); // adding the body to request

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