Documentation and tools.
Code Conventions for the Java™ Programming Language (https://www.oracle.com/java/technologies/javase/codeconventions-contents.html)
A respected (but no longer updated) style guide originally published by Sun, now made available by Oracle for archival purposes only.
Google Java Style Guides (https://google.github.io/styleguide/)
The foundation for the Java portion of this style guide, this is the most widely followed and actively updated Java style guide currently in use.
SQL Style Guide (https://www.sqlstyle.guide/), S. Holywell
Comprehensive guide, some portions have which have been incorporated into this style guide.
Common Programming Case Styles
Introduction to letter casing styles most commonly used in Java, SQL, XML, and JSON, with notes on general and DDC-specific usage.
intellij-java-google-style.xml (https://raw.githubusercontent.com/google/styleguide/gh-pages/intellij-java-google-style.xml)
Part of the Google Style Guide repository, this is a formatting scheme that can be imported into IntelliJ IDEA, providing extensive formatting support for Java source files, as well as less comprehensive support for XML and JSON formatting.
The tools listed here produce (with some configuration) code with formatting that’s conformant with the rules in this style guide. However, the recommended tool for this purpose is the IntelliJ IDEA Code/Format Code command.
Code Beautify: SQL Formatter (https://codebeautify.org/sqlformatter)
FreeFormatter.com: SQL Formatter (https://www.freeformatter.com/sql-formatter.html)
Instant SQL Formatter (http://www.dpriver.com/pp/sqlformat.htm)