= sg-java-format ifdef::env-github[] :tip-caption: :bulb: :note-caption: :information_source: :important-caption: :heavy_exclamation_mark: :caution-caption: :fire: :warning-caption: :warning: endif::[] ifndef::env-github[] :icons: font endif::[] :sectnums: :toc: :toclevels: 3 :toc-placement!: :xrefstyle: full

:uri-formatter-releases: https://github.com/Salling-Group/sg-java-format/releases :uri-google-formatter: https://github.com/google/google-java-format

sg-java-format reformats Java source code to comply with the named style. We forked {uri-google-formatter}[google-java-format] 1.9 and modified it to support custom styles to enforce the <<styleguide.adoc#,Salling Group Java style>>.

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To simplify integrating upstream changes, customizations in sg-java-format are kept to a minimum. A clear example of this is that sg-java-format itself is formatted using the Google style.

For more information about google-java-format, see link:google-README.md[the original project README].

== Using the formatter

The easiest way to use the formatter is to commit the link:scripts/javafmtw[] wrapper and its configuration--generated on its first execution--to your repository, at a location of your preference, and execute that. In that instance you will likely want to ignore the Jar file.

Alternatively you can {uri-formatter-releases}[download the formatter] and run it with:

[source,sh]

java -jar /path/to/sg-java-format-1-all-deps.jar [options] [files...]

While you don't have to do anything else to use sg-java-format, to actually take advantage of it you have to pass the --style option with one of its supported values, e.g. --style=salling-group.

NOTE: sg-java-format aims to be a drop-in replacement for the version of google-java-format it was forked from.

CAUTION: The only supported use of sg-java-format is as a self-contained JAR file invoked headlessly. google-java-format offers additional integrations; these are not supported.

=== In CI

In CI, use sg-java-format as above but include these two options:

--set-exit-if-changed:: Exit with non-zero status code if any of the named files would be reformatted.

--dry-run:: Print the paths to files that would be reformatted but don't reformat them. Optional, but helpful for troubleshooting.

[CAUTION]

sg-java-format cannot recurse through subtrees. For small sets of files you can leverage shopt -s globstar to name all Java files with \**/*.java. With very large sets of files this will exceed the command line limit and you will need to process files in batches. When processing individual batches you have to make a decision about how the options above should combine to determine failure in your execution environment, in particular whether it should fail immediately or only after processing all files.

== Motivation

Reasons for establishing a style guide and enforcing it with tooling are well understood and documented throughout the Internet and will not be reproduced here.

sg-java-format is based on google-java-format because that is a very well made application that solves the automatic formatting problem in a solid manner. google-java-format is non-configurable by design, which is highly advantageous in reducing human errors and misunderstandings and minimizing application complexity. These are desirable qualities for sg-java-format. Unfortunately Google's own Java style is radically different from most other style variants in a few key ways that make it difficult to adopt. These qualities are not desirable for sg-java-format, which is why we forked the project. There are many other tools that purport to solve this problem, most of them with built-in configurability, but they tend to disappoint in various other ways like being egregiously non-idempotent or taking excessively long time to run.

It is not sg-java-format{empty}'s goal to be "a configurable google-java-format{empty}".