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Mapping optional-1-1 relationships in hibernate
We use Hibernate to map our database tables to java objects. There are many problems with hibernate, and I'll probably end up going into them later.
With Hibernate you can have an object around, but not actually have got anything from the database yet. Instead you have a dynamically generated class which just knows the primary key, and can get the ( Read more... ) -
Javascript "Operation Aborted" in IE
Here's a more technical post, to balance out the blatant promotion ( Read more... ) -
Like We7? Dislike the adverts?
(Edit: Public now it's Sunday)
Or do you just like free stuff!
In case anyone doesn't know, We7 allows you to listen to music in your web browser, for free (though it does require javascript and flash). Although it's free, you have to listen to a short (2-5 second) advert before each song you listen to.
We're planning a monthly subscription service ( Read more... ) -
HttpUnit slow? Are you returning a contentLength of zero?
Our integration tests have been taking a long time for ages. They start up tomcat, and then make a load of web requests to it. When I say a load, it's more like 60 because people have been loath to add new tests as running them is so slow. Each new test takes 3 seconds, which sounds a lot.
( Why is it so slow? ) -
Debian exim rejects valid characters in local parts
If you have %, $, !, ?, |, `, # or & in your email address it will be rejected at any relay using the default debian exim config, despite being valid according to RFC2822.
Does anyone use these characters in their addresses? If so, I suspect you're not getting all your mail.
The comments in /etc/exim4/conf.d/acl/30_exim4-config_check_rcpt say:
( Read more... ) -
We7 Scrobbler
Woo! If, like me, you listen to music on We7, but want Last.fm to keep a record of what you listen to, you can now do this. Maybe you want to share it on your home page, maybe you want LJ to display what you're currently listening to.
You can use We7 Scrobbler. It requires you to be using Firefox as it's a Greasemonkey script. It works entirely ( Read more... ) -
Finding useless indexes in Postgres
It's always hard to work out when you need to create an index for your database, my general rule is to create an index if there's any doubt, paying particular attention to columns that reference other items as a foreign key (as postgres at least has to find all the rows that reference a row that you change to check that they're still valid), and ( Read more... ) -
Quartz cron trigger specs are not like cron
For some parts of our app, we use Quartz CronTrigger objects.
To specify when a task will run you give it a string telling it when to run. This string looks a bit like a crontab(5) entry. You think "That sounds like a good idea, it means that I don't need to learn a new way to specify these things. Now, look again at the CronTrigger documentation ( Read more... ) -
Java regular expressions and multi-lines
When using perl to match strings, you would quite often do something like:
if ($message =~ /value/) { print $message }
In java regular expressions such as used by String.matches have to match the whole string, so you would do
if (message.matches(".*value.*")) { System.out.println(message) }
Now, what happens if you do
if ("foo\nsome value ( Read more... ) -
Java quiz (Generics)
Consider the following program. It performs magic, by converting an Integer into a String. Obviously this doesn't work, but what actually happens?
1. class gen {
2. Object obj;
3. public gen(Object s) {
4. obj = s;
5. }
6. T test() {
7. return (T) obj;
8. }
9. }
10.
11. public class test {
12. ( Read more... )