AmbySoft Coding Standards for Java Very detailed, served as the foundation for "The Elements of Java Style" (2000)
Cay Horstmann's Java Language Coding Guidelines According to the author a simplified version of one that has been used with good success both in industrial practice and for college courses (2004)
Code Conventions for the Java Programming Language A style guide written by Sun, only covers the basics. Often seen as the official reference, though not taken too seriously by Sun itself (1999)
Geosoft Java Programming Style Guidelines Unlike all other documents mentioned here, comes in an annotated form that makes it easy to use during project code reviews (2004)
Infospheres Java Coding Standard Provides little discussion, but features interesting Javadoc guidelines (1999)
JavaRanch Java Programming Style Guide Covers mainly the same ground as the original Sun document, but gives different advice in some areas
Nejug Coding Standards for Java The most complete and up-to-date Java coding style document we know of. Compiled by the New England Java User Group (2001)
Code Complete
Steve McConnell, Microsoft Press, 2004, ISBN 0735619670
Just like "The
pragmatic programmer" a book that should be included in every software
engineering library. Devotes a whole chapter to code layout and style
Expert One-on-One J2EE Design and Development
Rod Johnson, Wrox, 2002, ISBN 0764543857
Devotes a whole chapter to design techniques and coding standards for J2EE
projects
The Elements of Java Style
Allan Vermeulen, Scott Ambler et. al., Cambridge University Press, 2000, ISBN 0 521 777682
Provides a set of rules for writing Java code that can be used as the Company's
coding standard. Falls short on some rules, but overall gives sound advice
Artistic Style Source Code Indenter written in C++. Supports C/C++ and Java
BeautyJ Java Source Code Formatter that demonstrates the use of a flexible Java source code framework
CheckStyle Java Coding Convention Checker
ImportScrubber Java import optimizer
Jacobe Java Source Code Formatter. Written in C, available for Windows and Unix (not Open Source, but free)
FOSS Jalopy The predecessor of the commercial Jalopy. Originally written by the founder of TRIEMAX Software (until 1.0b10), now maintained by the community
JCSC Java coding convention checker
Mozart Development Environment Framework for user extensible compilers and development tools
PMD Java source code analyser/checker
QDox Framework for extracting class/interface/method definitions
Recoder Source code metaprogramming framework