Re: URLConnection

From:
Erik <et57@hotmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Sun, 10 Jan 2010 12:10:52 +0100
Message-ID:
<vecjk5h2he4olnvaa7t943u7lt28c7o9dc@4ax.com>
GET-POST seems to be an issue here indeed. However,after adaptation
according to your suggestions, I still get a 500-error, from the W3C
site as well as my localhost.

Further below is the relevant piece of source code.

Firefox has this plug-in to invesxtigate HTTP data sent. this gives
the following when using the url :
http://jigsaw.w3.org/css-validator/validator?text=h2{margin-left:23px;}

=========================================
http://jigsaw.w3.org/css-validator/validator

POST /css-validator/validator HTTP/1.1
Host: jigsaw.w3.org
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US;
rv:1.9.1.7) Gecko/20091221 Firefox/3.5.7 (.NET CLR 3.5.30729)
Accept:
text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: http://jigsaw.w3.org/css-validator/
Content-Type: multipart/form-data;
boundary=---------------------------114782935826962
Content-Length: 666
-----------------------------114782935826962
Content-Disposition: form-data; name="text"

h2{margin-left:23px;}
-----------------------------114782935826962
Content-Disposition: form-data; name="profile"

css21
-----------------------------114782935826962
Content-Disposition: form-data; name="usermedium"

all
-----------------------------114782935826962
Content-Disposition: form-data; name="type"

none
-----------------------------114782935826962
Content-Disposition: form-data; name="warning"

1
-----------------------------114782935826962
Content-Disposition: form-data; name="lang"

en
-----------------------------114782935826962--

=======================================
the relevant piece of my source is this:

public class URLConnectionTest
{
   public static void main(String[] args)
   {
      try
      {
         String urlName =
"http://jigsaw.w3.org/css-validator/validator";

         URL url = new URL(urlName);
         HttpURLConnection con = (HttpURLConnection)
url.openConnection();
         con.setRequestMethod("POST");
         con.setDoOutput(true);
         PrintWriter os = new PrintWriter(con.getOutputStream());

 os.print("text="+ URLEncoder.encode("h2{margin-left:34px;}", "UTF-8")
+ "&" );
            os.print("profile"+ URLEncoder.encode("css21", "UTF-8") +
"&" );
            os.print("usermedium="+ URLEncoder.encode("all", "UTF-8")
+ "&" );
            os.print("type="+ URLEncoder.encode("none", "UTF-8") + "&"
);
            os.print("warning="+ URLEncoder.encode("1", "UTF-8") + "&"
);
            os.print("lang="+ URLEncoder.encode("en", "UTF-8") );

         os.close();
         // print header fields

         int n = 1;
         String key;
         while ((key = con.getHeaderFieldKey(n)) != null)
         {
            String value = con.getHeaderField(n);
            System.out.println(key + ": " + value);
            n++;
         }

         // print convenience functions

         System.out.println("----------");
         System.out.println("getContentType: "
            + con.getContentType());
         System.out.println("getContentLength: "
            + con.getContentLength());
         System.out.println("getContentEncoding: "
            + con.getContentEncoding());
         System.out.println("getDate: "
            + con.getDate());
         System.out.println("getExpiration: "
            + con.getExpiration());
         System.out.println("getLastModifed: "
            + con.getLastModified());
         System.out.println("----------");

         BufferedReader in = new BufferedReader(new
            InputStreamReader(con.getInputStream()));

         // print first ten lines of contents

         String line;
         n = 1;
         while ((line = in.readLine()) != null && n <= 100)
         {
            System.out.println(line);
            n++;
         }
         if (line != null) System.out.println(". . .");

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

On Sat, 09 Jan 2010 18:07:26 -0500, Arne Vajh?j <arne@vajhoej.dk>
wrote:

On 09-01-2010 16:28, Erik wrote:

I do:
  URLConnection conn = url.openConnection();
conn.setDoOutput(true);

and get an error : already connected
on the doOutput.

openConnection is not supposed to connect , is it ?
.connect is....

I'm on localhost, Tomcat 5.port 8080, Netbeans 6.8.


Can we get a bit more context?

I have used:

HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("POST");
con.setDoOutput(true);
OutputStream os = con.getOutputStream();
os.write(b);
con.connect();

many times.

Maybe GET vs POST ??

Arne

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