Hello Yakov,
how can I read data in real time from java applet for example:
http://www.saxobank.com/?id=911&Lan=EN&Au=1&Grp=5

hi,
can any one tell me how can i read the parameters from URL that has been passed by someone ie id someone send id=123 then how can i get it,how the whole process work & last but the mostimp i want to do whole thing through core java.
Bye

Great Article! Keep''m coming!
There is also a good WebCopy implementation at:
http://www.acme.com/java/software/
It makes all the web references local - It does not work on HTTPS - I wish I had all the know-how & code to make an equivalent HTTPS WebSiteReader, which would be very handing for testing our query pages.
Thanks!

I am very happy with your code, Yakov.
I tried it and everything works very well.
Thanks Ferruccio

In this lesson I do this using HTTP GET request by attaching parameters to the URL after a question mark separated with an ampersand.

Fo HTTP POST, after getting the URLConnection stream, do something like this:

urlConn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
urlConn.setDoOutput(true);

String myData = "myParam1=" + URLEncoder.encode ("abc") +
"&myParam2=" + URLEncoder.encode ("xyz");

DataOutputStream encodedParams = new DataOutputStream (urlConn.getOutputStream ());

encodedParams.writeBytes (myData);
encodedParams.flush ();
encodedParams.close ();

Ok. What you say occurs when you have a page with a form. Well known. But my question was: you want to read the stream (see your last article) and perhaps manipulate it. You then use the code:
java.net.URL url = new java.net.URL("http://www.cgi.com");
java.net.URLConnection c = url.openConnection();
java.io.DataInputStream dis = new java.io.DataInputStream(c.getInputStream());
and so on.
How can you give the parameters to the cgi with THESE code lines?

Well, here''s the sample from my book "The Java Tutorial for the Real World".

1. An HTML form has 2 fields to perform a book search:

Find a book

Enter a word from the book title:

2. The servlet FindBooks runs on the server side, gets the parameters and sends back to the browser a page that reads that this book cost $65:

public class FindBooks extends javax.servlet.http.HttpServlet {

public void doGet(HttpServletRequest req,
HttpServletResponse res)
throws ServletException, IOException {
String title;
PrintWriter out = res.getWriter();
title = req.getParameter("booktitle");
res.setContentType("text/html");

out.println("");

out.println("the book "+title+" costs only $65");

out.println("Please enter your credit card number");

out.println("");
}
}

Thank you for your answer. I have several good Java books, but I didn''t find how I can read a CGI URL stream passing POST parameters in the calling instruction anywhere. Tell me please in a few words the way, if it is possible.

Ferruccio,

Java Servlets and JavaServer Pages technologies deal with HTTP Post and Get requests, parameters, etc. Wait for my lesson on servlets, or get a good book if you need to know the answer now.

I add to my above question: how can I pass the parameter values calling the URL?

What about reading a CGI URL accepting METHOD=POST parameters?

Dennis,

You can run on the remote machine one of the following: RMI server, SocketServer, a Servlet,FTP server... that has to create an instance of the class java.io.File that points at your directory. The File.list() will return the list of files in this directory as a String array. Now create instances of File for each of the array elements and call File.lastModify() to check the timestamp. After finding the file with the proper date, send its URL (or a stream reference) to the client for reading.

I found the article useful, and above average in clarity.

I am wondering if anyone knows how you set up the
connection to download an (entire) directory of files?
and to check the file dates before doing so?

Yakov,

You should mention that HttpURLConnection may ''hang'' when contacting servers that don''t behave correctly. This can cause a lot of problems in a server side application. The solutions are:
1) Use something other than URL/URLConnection/HttpURLConnection.
2) Set the system properties that control the socket timeouts for the Sun HTTP client.

Very useful, clear.