I recently discovered a tool for checking Java code formatting and other coding style related issues -- CheckStyle. It features a list of style checks such as

...
* Restricts nested boolean operators (&&, ||, &, | and ^) to a specified depth (default = 3).
* Checks for empty blocks.
* Checks for long source files.
...

There's also an Eclipse plugin for it: https://checkstyle.org/eclipse-cs/#!/. The Eclispe update URL is http://eclipse-cs.sf.net/update/. As of at least Eclipse 4.8.0 (Aug., 2018), this update URL no longer works.

There is a caveat at the time I install it:

the plugin's homepage http://eclipse-cs.sourceforge.net/ gives http://sevntu-checkstyle.github.com/sevntu.checkstyle/update-site/ as the installation URL, but it does not work. However on http://eclipse-cs.sourceforge.net/downloads.html a different installation URL http://eclipse-cs.sf.net/update/ is given, which turns out to work correctly. It seems someone has not updated the Web pages consistently. And it has certainly confused some: http://stackoverflow.com/questions/11865025/error-while-installing-check-style-plugin-for-eclipse.