Everytime I need one or more Java packages or components, I always use sourceforge.net or freshmeat.net. Everyone know about this. This site is very useful for me either as system analyst or Java programmer.
Today, I have found a good site, i.e. Java Open Source, which provide a list of Java open source projects. May be you already know about this site, but for me I want to note at my blog to share with other.