Describing Maven Plugins with help:describe option

If you do any non-trivial customization of a Maven build, you’ll understand that you need to have a good understanding of Maven Plugin configuration. What configuration parameters are available for a particular plugin goal? Most users tend to Google for the particular Maven plugin and rely on the fact that most Maven-generate plugin sites contain a standard list of goals and configuration parameters. While this works, there is a better way: use the Maven Help plugin’s describe goal to list the available configuration parameters for a Maven plugin.

Describing Plugin Configuration Parameters with a Command

$ mvn help:describe -Dcmd=compiler:compile
[INFO] [help:describe {execution: default-cli}]
[INFO] 'compiler:compile' is a plugin goal (aka mojo).
Mojo: 'compiler:compile'
compiler:compile
  Description: Compiles application sources
  Deprecated. No reason given

Sure, the compile goal in the compiler plugin will compile application sources. That’s not exactly what you were looking for, what you usually need is a detailed list of plugin configuration parameters. You can get this by passing in a -Ddetail argument.

$mvn help:describe -Dcmd=compiler:compile -Ddetail
[INFO] [help:describe {execution: default-cli}]
[INFO] 'compiler:compile' is a plugin goal (aka mojo).
Mojo: 'compiler:compile'
compiler:compile
  Description: Compiles application sources
  Deprecated. No reason given
  Implementation: org.apache.maven.plugin.CompilerMojo
  Language: java
  Bound to phase: compile

Available parameters:

compilerArgument
  Sets the unformatted argument string to be passed to the compiler if fork
  is set to true.

  This is because the list of valid arguments passed to a Java compiler
  varies based on the compiler version.
  Deprecated. No reason given

compilerArguments
  Sets the arguments to be passed to the compiler (prepending a dash) if
  fork is set to true.

  This is because the list of valid arguments passed to a Java compiler
  varies based on the compiler version.
  Deprecated. No reason given

compilerId (Default: javac)
  The compiler id of the compiler to use. See this guide for more
  information.
  Deprecated. No reason given

compilerVersion
  Version of the compiler to use, ex. '1.3', '1.5', if fork is set to true.
  Deprecated. No reason given

debug (Default: true)
  Set to true to include debugging information in the compiled class files.
  Deprecated. No reason given

encoding
  The -encoding argument for the Java compiler.
  Deprecated. No reason given

excludes
  A list of exclusion filters for the compiler.
  Deprecated. No reason given

executable
  Sets the executable of the compiler to use when fork is true.
  Deprecated. No reason given

failOnError (Default: true)
  Indicates whether the build will continue even if there are compilation
  errors; defaults to true.
  Deprecated. No reason given

fork (Default: false)
  Allows running the compiler in a separate process. If 'false' it uses the
  built in compiler, while if 'true' it will use an executable.
  Deprecated. No reason given

includes
  A list of inclusion filters for the compiler.
  Deprecated. No reason given

maxmem
  Sets the maximum size, in megabytes, of the memory allocation pool, ex.
  '128', '128m' if fork is set to true.
  Deprecated. No reason given

meminitial
  Initial size, in megabytes, of the memory allocation pool, ex. '64',
  '64m' if fork is set to true.
  Deprecated. No reason given

optimize (Default: false)
  Set to true to optimize the compiled code using the compiler's
  optimization methods.
  Deprecated. No reason given

outputFileName
  Sets the name of the output file when compiling a set of sources to a
  single file.
  Deprecated. No reason given

showDeprecation (Default: false)
  Sets whether to show source locations where deprecated APIs are used.
  Deprecated. No reason given

showWarnings (Default: false)
  Set to true to show compilation warnings.
  Deprecated. No reason given

source
  The -source argument for the Java compiler.
  Deprecated. No reason given

staleMillis (Default: 0)
  Sets the granularity in milliseconds of the last modification date for
  testing whether a source needs recompilation.
  Deprecated. No reason given

target
  The -target argument for the Java compiler.
  Deprecated. No reason given

verbose (Default: false)
  Set to true to show messages about what the compiler is doing.
  Deprecated. No reason given

That’s more like it. If you ever find yourself wondering what a particular plugin configuration parameter’s name is, or what a default value for a parameter is. You now know how to find it.