Develop Reference

server calls goes in infinite loop in hibernate

At particular page in the project, I get output on the page.
When I refresh the page then also I get the same output. This is absolutely correct.
But when I refresh the page third time it shows busy browser and never return anything on the page. I am using tomcat server, hibernate, spring.
Due to busy browser and it never show anything ever, I have to restart the tomcat server.
Now history repeats. Third refresh make browser busy which doesn't fetch anything.
Is there any problem in hibernate ?
You first question would be like, what logs you are getting?
I see nothing in the log.

jsoup - how to check if a webpage exist or not

Hi stackoverflow users.
When i was doing web scraping, i encountered a problem that, when i scrape through a series of webpages of a particular site, with their URLs being
http://www.somewebsites.com/abc.php?number=0001
http://www.somewebsites.com/abc.php?number=0002
http://www.somewebsites.com/abc.php?number=0003
..
..
http://www.somewebsites.com/abc.php?number=1234
Something like this. Since some of the pages may be occasionally down and the server may handle it by redirecting to a different page, say the homepage. In this way, my scraping program will encounter various exceptions related to the change in syntax structure ( as it is a different page).
I'm wondering if there is a way to check whether a webpage i'm scraping exists or not, to prevent my program from being terminated in this case.
I'm using
Jsoup.connect()
to connect to that page. However, when i visit the failed webpage ( redirected ), i was redirected to another page. In my program, the console do not throw any exception about the connect. Instead, the exception is just an index out of bound exception because the unexpected redirected webpage has a totally different structure.

Since some of the pages may be occasionally down and the server may handle it by redirecting to a different page, say the homepage
In general, when a page on a website is not temporarily available and gets redirected, the client gets the response code as 302 (moved permanetly) or 307 (moved temporarily) with "Location" header that points to the redirected page. It seems you can configure the Connection to not redirect in such cases, by setting the followRedirects to false. Then you can verify the HTTP response code before converting the response to Document for further processing.

Spring mvc result page and back browser button

On my MVC spring application I send a form to a page using post method to perform a search with some parameters. The results of the search is a list and, for every entry is possible to navigate to a details page. It works fine but, when an user try to come back to result page with back browser button (or a Javascript), I get an "Expire page" error. Refreshing the page, it rexecutes the post submit and it works fine.
To prevent this error I added
response.setHeader("Cache-Control", "no-cache");
to the search controller and everything works fine with Safari and Firefox but I get the same "Expire page" error when I try to execute the web application with IE (8 and 9).
What's the right way to go to a detail page and come back without getting any error?
thanks for your time!Andrea

The right way is to use GET instead of POST: searching is an idempotent operation which doesn't cause any change on the server, and such operations should be done with a GET.

Not expiring a POST request seems to undermine the very idea of a POST:
Per RFC 2616, the POST method should be used for any context in which a request is non-idempotent: that is, it causes a change in server state each time it is performed, such as submitting a comment to a blog post or voting in an online poll.
Instead, I would restructure how you view the detail records, maybe with an overlay DIV that doesn't refresh the underlying page that shows the results. With many modern web apps, using the BACK button can cause issues with page flow.

Wicket excel Page expired

After using WebResponse to export excel then clicking a Link gives Page expired error.
Any suggestions ?
Thanks.

The session expired page usually appears when your pages are not bookmarkable and you make a request for a page to the server but the server has a different version of the page that you have requested. It shouldn't have anything to do with the session time out which is defined in the web.xml file.
As a good practice, your pages should have a constructor with PageParameters. Also be careful with the popup pages because they usually generate these kind of errors when they are not using PageParameters.

Make sure that your classes that don't extend wicket components use implements Serializable, otherwise you will often see a Page Expired error.
If this doesn't help, copy and paste the error logs so we can see the exception being thrown.

Importing the content of another web resource using JSTL

I have a JSP page that will display the exact content of another web page on a different server. My understanding was that c:import from the JSTL should be able to include content from files that are not part of the current web application.
I added c:import url="page on my server in a different application" and it works fine, but when I try to include a page from another server it fails.
Any suggestions as to what might be wrong?
EDIT: The exact error is: "The server encountered an internal error () that prevented it from fulfilling this request.". However, requesting a page from the same server, different app works...I get the content of the page.

I had a similar error once. It turned out to be that the machine that I was running the app on had some problems connecting to the internet through the firewall. Once I deployed the app to a machine that was always connected it worked fine.

An exact code and how "it fails" would be a great help. All mind-readers are currently on vacation.
Meanwhile, take a look at http://www.ibm.com/developerworks/java/library/j-jsp06173.html
<%# taglib prefix="c" uri="http://java.sun.com/jstl/core" %>
...
<c:import
url="http://www.truenorthguitars.com/Clients/Richman/index.htm" />

If it works from the same server, different app, makes it possible that there's a variable that's not being initialized somewhere, or some state which makes it throw an exception. Check the error logs for any stack traces that could point to the specific line of code that's causing the problem.