Where to keep my passwords

I posted a topic on the ranch about where I should keep my user names and passwords. Somebody told me a properties file would be a good place. Why? Couldn't someone just open it and change the data? I'm using a message digest so I don't think they could get into the program, but they sure could mess it up, right?
My idea is to use a database with a password on it, so the only way the could access the database is if they had the source code.
Am I correct on these assumptions? Thanks

Depending on how you set it up, a database could actually be less secure than a properties file. Most modern databases provide network connectivity by default, so for someone to attempt to hack into the database might be easier than you think.

Can you secure a properties file (with a password)? Or should I just encrypt it?
Thanks for the reply

Is there a place where I can find out more about using a properties file (or using passwords) in Java? I've searched the Sun's Java website and haven't found anything really useful. Thanks

Here are some:
sun site info
and another
and another