Java properties: .properties files vs xml?

Question

I'm a newbie when it comes to properties, and I read that XML is the preferred way to store these. I noticed however, that writing a regular .properties file in the style of

foo=bar fu=baz 

also works. This would mean a lot less typing (and maybe easier to read and more efficient as well). So what are the benefits of using an XML file?

Answer 1

In XML you can store more complex (e.g. hierarchical) data than in a properties file. So it depends on your usecase. If you just want to store a small number of direct properties a properties file is easier to handle (though the Java properties class can read XML based properties, too).

It would make sense to keep your configuration interface as generic as possible anyway, so you have no problem to switch to another representation ( e.g. by using Apache Commons Configuration ) if you need to.

Answer 2

The biggest benefit to using an XML file is that XML declares its encoding, while .properties does not.

If you are translating these properties files to N languages, it is possible that these files could come back in N different encodings. And if you're not careful, you or someone else could irreversibly corrupt the character encodings.