1

I am currently trying to handle some incoming POST requests in Java.

It is working partly so far. I can receive the requests, but I can't seem to extract the parameters and values sent with the request.

Here is my Java code for receiving the requests so far:

public HybridRemoteReceiver() {

try {
    System.out.println("running...");
    ServerSocket ss = new ServerSocket(3434);

    int i = 0;
    while (true) {
        Socket client = ss.accept();
        BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
        String line;

        while ((line = in.readLine()) != null) {
            if (line.length() == 0)
                break;
            i++;
        }
        in.close();
        client.close();
    }


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

}

I am aware that there is a class called HttpServer, but It's like this class doesn't exist in Java.

I am using java 1.8 in eclipse btw.

However, I can find the classes HttpExchange and HttpHandler, but can't seem to make them work.

Basically what I want to achieve, is to receive the data sent with the post request and NOT send anything back to the client.

I really hope anyone can help me out with this.

Arjan Tijms
  • 37,782
  • 12
  • 108
  • 140
Langkiller
  • 3,377
  • 13
  • 43
  • 72
  • If I could tell you how to use `HttpServletRequest` would you be interested in using it? – Kevin Bowersox Apr 10 '15 at 20:29
  • 1
    You really should be working with a servlet container (Tomcat, etc.) rather than trying to re-invent the wheel. In order to do what you want, you need to actually parse the lines sent to you in the POST according to the standards. Also, to comply with the standards you'll have to send a reply, even if it has no body, just headers. – RealSkeptic Apr 10 '15 at 20:30
  • Thanks for your answers both. @Kevin Yes I would be very interestedif you could explain. But before you do, is it possible to use servlets in a standard java application using swing (or similar) as the gui? Because i need it to be a desktop application, receiving the post requests data. Thanks in advance :) – Langkiller Apr 11 '15 at 07:17

3 Answers3

2

Use a servlet container like tomcat.

Then, study Servlets (extends HttpServlet), you can use its GET and POST method.

Here is the POST.

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        username = request.getParameter("username");

}

//username is a parameter that was sent via POST from a JSP.

shepard23
  • 148
  • 2
  • 13
  • Thank for your answer! Is it possible to make a simple java application with Swing (or similar) using Servlets. I don't really have much experience with servlets. – Langkiller Apr 11 '15 at 06:38
  • Ofcourse. Here http://stackoverflow.com/questions/9090580/sending-data-from-swing-to-servlet But why make it a swing based application? Web-App-ing your application is better, unless you have desired to make it a stand alone.. – shepard23 Apr 11 '15 at 07:34
  • Cool! But doesn't that require me to make 2 different applications, which communicates? Or can I make it into a single stand alone desktop app? And do you know if is complicated to just extract the post parameters from the request ? Because it was fairly easy to receive the post request directly with the code in my question.. – Langkiller Apr 11 '15 at 08:17
  • What is your application? I cannot give an answer before you give me details.. anyway, please accept my answer and vote up if I had help you. Thanks – shepard23 Apr 11 '15 at 09:45
  • My application is an experiment where i want it to receive these post requests and perform different kinds og tasks, like performing keystrokes abd so on. Your answer is useful if i can use it as described in a stand alone java app. Then i will of course accept and vote up. Btw I really appreciate your help :) – Langkiller Apr 11 '15 at 10:02
  • extracting Post/Get Parameters is not at all hard, the one i posted as the answer is the way to get parameters.. You can even pass those parameters to other servlets – shepard23 Apr 11 '15 at 10:02
0

If you are looking to handle HTTP requests it would be best practice to use a servlet container such as Tomcat. Tomcat will not implement the entire Java EE specification but will provide you with an implementation of a servlet container, which will be able to handle the post request easily. This keeps you from reinventing the wheel and allows you to rely upon a proven technology incorporated into many projects.

Once the servlet containers libraries are on the classpath, you will then be able to use classes such as HttpServletRequest. One you have the servlet container stood up and a Servlet declared and mapped, its as simple as calling the HttpServletRequest#getParameter() method.

Arjan Tijms
  • 37,782
  • 12
  • 108
  • 140
Kevin Bowersox
  • 93,289
  • 19
  • 159
  • 189
  • Thank for your answer! Is it possible to make a simple java application with Swing (or similar) using Servlets. I don't really have much experience with servlets. – Langkiller Apr 11 '15 at 06:38
0

There is indeed a HttpServer class, it is found somewhere within the sun.net.httpserver package.

The sun package and subpackages are safe to use, unlike the com.sun package and subpackages, which may be (re)moved.

Edit: If you want to, you can always write your own server. If you wish to do so, make sure it follows all the RFCs that define the HTTP version you'll be using. Certain things are not necessary and you can just throw a 501 Not Implemented at them.

ThePyroEagle
  • 153
  • 12