The Java code here uses Eclipse's code formatting capability to format Java code. You don't need Eclipse installed to use it; the build bundles all of the Eclipse libraries necessary.
$ mvn package
$ java -cp java-formatter-jar-with-dependencies.jar sample.opts
The only required argument is a file listing code formatter options for
Eclipse's DefaultCodeFormatterOptions class that should be applied over the
top of the standard Java settings. Each line in the file should be:
<field name>:<type>:<value>
A blank file ought to be fine. Comment lines starting with '#' and blank lines are ignored.
When run like the above, the formatter reads code from standard input. Formatted code is written to standard output.
$ java -cp java-formatter-jar-with-dependencies.jar sample.opts MyFile.java
You can pass a file name instead of using standard input.
$ java -cp java-formatter-jar-with-dependencies.jar sample.opts src/java
If you pass a directory, the formatter will recursively format all Java files in the directory. Formatted code is written to new files prefixed with "formatted_", e.g., formatted_MyFile.java is the formatted form of MyFile.java.
The formatter is heavily based on work published here:
https://ssscripting.wordpress.com/2009/06/10/how-to-use-the-eclipse-code-formatter-from-your-code/