This is my equivalent to the Apache-Commons.
In my spare time I write Java code for embedded devices: this code must be as small as possible (low RAM footprint). This is the reason I can not use all the libs I'd like to use.
Sinve early 2000 (this millenium) I've beeing creating this lib by adding the functions I needed.
It is 97% documented in English and test coverage is around 95%.
If you find it useful, go ahead with it.