It sounds like a job for the Function List plugin.
To install it, simply follow the instructions in install.txt inside of the .zip file.
It doesn't appear to work with Java out of the box, but you can follow this guide to make it work properly. Alternatively, you can manually add the following to the configuration XML file, inside of the Java section:
<Group name="METHOD" subgroup="" icon="0" child="0" autoexp="0" matchcase="1" fendtobbeg="" bbegtobend="\{" keywords="">
<Rules regexbeg="\w*[\s\*]*" regexfunc="\w+\s*[\s\*]*" regexend="\(.*\)" bodybegin="\{" bodyend="\}" sep="" />
</Group>