Where should I put application configuration files for a Maven project?

Question

I'm using the Maven Application Assembler plugin to generate stand-alone executables from my Java project. The application reads in configuration files, including Spring files. The Application Assembler plugin has an option (activated by default) to add a etc/ directory to the application's classpath, but what should I do to have the plugin copy my configuration files to this directory?

Or more generally, where is in Maven the kosher location for application configuration files that should NOT be packaged in the artifact?

Answer 1

For folks who have come to this more recently there is, since version 1.1 of the Application Assembler Plugin, the optional parameters configurationSourceDirectory and copyConfigurationDirectory. Please find them in an example POM.xml extract below:

<configuration>
  <!-- Set the target configuration directory to be used in the bin scripts -->
  <configurationDirectory>conf</configurationDirectory>
  <!-- Copy the contents from "/src/main/config" to the target
      configuration directory in the assembled application -->
  <copyConfigurationDirectory>true</copyConfigurationDirectory>
  <!-- Include the target configuration directory in the beginning of
      the classpath declaration in the bin scripts -->
  <includeConfigurationDirectoryInClasspath>
    true
  </includeConfigurationDirectoryInClasspath>
...
</configuration>

More information is here

Answer 2

You can also use resource filtering: http://maven.apache.org/guides/getting-started/index.html#How_do_I_filter_resource_files

turn on filtering:

...
<build>
...
<resources>
      <resource>
        <directory>src/main/resources</directory>
        <filtering>true</filtering>
      </resource>
    </resources>
...
</build>
...

make a file under src/main/resources like: application.properties

application.properties

configprop.1=${param1}
configprop.2=${param2}

Then setup a profile and set some properties perhaps in a settings.xml that sets different properties depending on if this is a dev or production build. see: http://maven.apache.org/guides/introduction/introduction-to-profiles.html

I have different properties set depending on if this is the build server, dev or a production deployment

mvn -Denv=dev || mvn -Denv=dev-build || mvn -Denv=production

The maven link has a pretty good description.