Re: Wonky HTTP behavior?

From:
RedGrittyBrick <RedGrittyBrick@SpamWeary.foo>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 13 Nov 2006 20:00:19 +0000
Message-ID:
<WZWdnctj_I9TU8XYnZ2dnUVZ8qudnZ2d@bt.com>
Twisted wrote:

The code generating the initial connection is:

uc = (HttpURLConnection)u.url.openConnection();
uc.setInstanceFollowRedirects(true); // Auto follow what redirects we
can.
uc.setRequestProperty("User-Agent", Main.USER_AGENT);
uc.setRequestProperty("Accept-Language", "en-us,en;q=0.5");
uc.setRequestProperty("Accept-Charset",
"ISO-8859-1,utf-8;q=0.7,*;q=0.7");
uc.setRequestProperty("Keep-Alive", "300");
if (u.prevURL != null) {
    uc.setRequestProperty("Referer", u.prevURL);
}
if (Main.COOKIE_ENABLE) {
    String k = getCookiesFor(u.url.getHost());
    if (k != null) uc.setRequestProperty("Cookie", k);
}
uc.connect();

So, three questions:
1. Is the "Content-type" header what's screwing things up and causing
400 errors or worse?
2. How do I get rid of it?
3. Is the header rearrangement (relative to what Firefox outputs) a
likely source of problems?


I tried your code as below and got
Response code: 200 'OK'.

------------------------------------------------------------------------
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class WebGet {

     public static void main(String[] args) throws IOException {

         /*
          * Contrived class so Twisted's code snippet
          * can be used unchanged.
          */

         class Foo {
             URL url;
             String prevURL;
             Foo() {
                 try {
                     url = new URL("http://www.movingtofreedom.org/" +
                             "2006/11/12/" +
                             "a-round-of-gnu-linux-" +
                             "heading-in-to-the-back-nine-part-2/");
                 } catch (MalformedURLException e) {
                     e.printStackTrace();
                 }
             }
         }
         Foo u = new Foo();
         HttpURLConnection uc;

         // Twisted's code starts here
         // ..........................................................
         uc = (HttpURLConnection)u.url.openConnection();
         uc.setInstanceFollowRedirects(true);
         uc.setRequestProperty("User-Agent", Main.USER_AGENT);
         uc.setRequestProperty("Accept-Language", "en-us,en;q=0.5");
         uc.setRequestProperty("Accept-Charset",
                 "ISO-8859-1,utf-8;q=0.7,*;q=0.7");
         uc.setRequestProperty("Keep-Alive", "300");
         if (u.prevURL != null) {
             uc.setRequestProperty("Referer", u.prevURL);
         }
         if (Main.COOKIE_ENABLE) {
             String k = getCookiesFor(u.url.getHost());
             if (k != null) uc.setRequestProperty("Cookie", k);
         }
         uc.connect();
         // ..........................................................
         // Twisted's code ends here

         System.out.println("Response code: "+uc.getResponseCode() +
                            " '"+uc.getResponseMessage()+"'.");
     } // main()

     private static String getCookiesFor(String host) {
         return null;
     }
} // WebGet

class Main {
     static String USER_AGENT = "Foo";
     static Boolean COOKIE_ENABLE = false;
}
------------------------------------------------------------------------

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