For my projects, in Eclipse I set up a specific code style (Windows | Preferences | Java | Code Style | Formatter) and compiler warnings/errors (Windows | Preferences | Java | Compiler | Errors/Warnings) and make all team members use those settings. I require that before any code gets placed in source control that Eclipse does not highlight any errors or warnings, but if a warning is necessary then a comment must appear in the code to justify the warning.
In addition, I use the CheckStyle plugin in Eclipse, and in the Maven and Ant build scripts.
There was another standalone tool I used at one point, but cannot offhand recall what it was - it is no longer on my PC.
This allows us to concentrate on reviewing algorithms when doing code reviews.