Alan's Ramblings - Web category

mod-rewrite equivalent for Tomcat

Wed, 02 Jun 2010 17:15:00 GMT

I've migrated and merged my old blogs.sun.com and bleaklow.com blogs into this new one, using Pebble. As a result, there are a number of links out there on the interwebs to bleaklow.com that are now broken, as everything has moved around - google's webmaster tools gives me a comprehensive list. If I was hosting this blog using Apache, the standard solution would be to use the most excellent mod-rewrite Apache module to redirect the broken links to somewhere appropriate. However Pebble is a J2EE application and uses Tomcat instead of Apache. I've been looking for an equivalent to mod-rewrite for a while and never managed to find anything. Whilst looking for something else entirely (always the way) I found Url Rewrite Filter. This is functional equivalent to mod-rewrite for J2EE servers, and offers most of the same features as mod-rewrite. I'm using it and it seems to do the job just fine, and the beta even has a mod-rewrite style configuration option, if you need a security blanket :-)

Simple parser for MovableType exports

Sun, 23 May 2010 10:03:00 GMT

As part of moving my blog over to I needed to be able to transfer the content from my old MovableType blog and my blogs.sun.com blog, which runs on Roller. Both MT and Roller can export in MovableType export format and Pebble has a MT importer, so it looked relatively straightforward. However when I looked at the content I was importing it was clear I'd need to munge it on its way into Pebble. The Pebble MT importer is one-pass and loads the entries into Pebble as it reads them, whereas I wanted to read them in, munge them and only then load them into Pebble, so I wrote a simple parser to read in the MT export. It's not a thing of great beauty but it got the job done. I thought it might be useful for other people who want to read MovableType exports from Java, so I've put a copy of it here.

Image thumbnailer for Pebble

Sun, 23 May 2010 08:54:00 GMT

This blog uses the Pebble package for delivering content. Pebble isn't a particularly common blogging package but it fits my purely personal and subjective requirements:

Not written in PHP (blegh)
Open source, and something in Java would be nice
Doesn't use a database and uses flat files that I can manage manually if I need to
Good RSS, search, tag and category management
Can be restyled easily

The old incarnation of this blog used MovableType but that doesn't really tick the Open Source box any more. blogs.sun.com uses Roller but that requires a database back-end. All these constraints combined to give a pretty short list of candidates, i.e. Pebble.

One thing that Pebble lacks is an image thumbnailer. I'm not bothered about glossy JavaScript solutions such as Lightbox, and I'm quite happy to type in HTML table definitions. All I wanted was something to save me the tedium of manually generating the thumbnails and typing in the HTML to display them and link to the full-size image in a popup window. MovableType has this feature but Pebble doesn't so I sat down one evening and knocked together an equivalent as a Pebble plugin, using the standard Java2D APIs to do the image manipulation. All the thumbnails on this site are done with it, and I've submitted this as a patch to Pebble so hopefully it will make it into a future release.

Update

The patch has been accepted and should be appearing in a future version of Pebble.

Facebook: do I get to say "I told you so?"

Thu, 07 Feb 2008 12:26:17 GMT

Just noticed that slashdot is running a story on Facebook applications and data privacy:

Privacy activists are rallying around yet another major issue at Facebook, in which the company is secretly sharing user data with third parties. Researchers from the University of Virginia recently announced that in a study of the top 150 Facebook applications, more than 90% were given access to information that was not needed to function correctly. That Scrabble or Superpoke application you really like? Its developers get access to your religion, sexuality and home town.

The slashdot article links to articles at The University of Virginia and news.com. The University of Virginia article says that 90% of the top 150 Facebook applications request personal data that they don't need in order to function:

When Jane installs a Facebook application, the application is given the ability to see anything that Jane can see. This means that the application can request information about Jane, her friends, and her fellow network members. The owner of the application is free to collect, look at, and potentially misuse this information. The Facebook Terms of Use agreement tells application developers not to do this, but Facebook has no way of finding out or stopping them.

I'll merely point out that I already told you so :-)

Facebook faces privacy questions

Fri, 18 Jan 2008 15:27:21 GMT

Just noticed this report on the BBC News website:

Facebook is to be quizzed about its data protection policies by the Information Commissioner's Office.

The investigation follows a complaint by a user of the social network who was unable to fully delete their profile even after terminating their account. Currently, personal information remains on Facebook's servers even after a user deactivates an account.

Facebook has said it believes its policy is in "full compliance with UK data protection law".

"We take the concerns of the ICO [Information Commissioner's Office] and our user's privacy very seriously and are committed to working with the ICO to maintain a trusted environment for all Facebook users and ensure compliance with UK law," said a statement from the site.

That'll be me they are talking about...