Is there a way to post-process project generated f

Question

Say I have an archetype and I generate a project from it. But I would like to resolve placeholders in a property file of the project I generated on after generation time by passing the value for placeholder through command line.

For example having the following command line:

mvn archetype:create -DarchetypeGroupId=... -DarchetypeArtifactId=... -DarchetypeVersion=1.0 -DgroupId=... -DartifactId=my-project -Dversion=1.0-SNAPSHOT -Dhello=Hello!

say the archetype contains app.properties (as part of project which is being generated) with the following content:

greeting=${hello}

Is it possible to replace ${hello} with "Hello!" right after project has been generated as a result of mvn archetype:create command?

Answer 1

You could define additional properties in the archetype, following the format: https://maven.apache.org/archetype/maven-archetype-plugin/specification/archetype-metadata.html

For example:

define the file: src\main\resources\META-INF\maven\archetype-metadata.xml

<archetype-descriptor 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns="http://maven.apache.org/plugins/maven-archetype-plugin/archetype-descriptor/1.0.0"
  xsi:schemaLocation="http://maven.apache.org/plugins/maven-archetype-plugin/archetype-descriptor/1.0.0 http://maven.apache.org/xsd/archetype-descriptor-1.0.0.xsd" 
  name="modelant.metamodel.api">

<requiredProperties>
  <requiredProperty key="package"><defaultValue>${groupId}.${artifactId}</defaultValue></requiredProperty>

  <requiredProperty key="parentGroupId"><defaultValue>${groupId}</defaultValue></requiredProperty>
  <requiredProperty key="parentArtifactId"><defaultValue>${artifactId}</defaultValue></requiredProperty>
  <requiredProperty key="parentVersion"><defaultValue>${version}</defaultValue></requiredProperty>

  <requiredProperty key="metamodelUrl"/>
 </requiredProperties>
</archetype-descriptor>

Here you see that it defines additional required properties, so they have to be mandatorily provided within the dialog, where:

• some properties may have no value - see metamodelUrl
• some properties may have default values either -- as static text -- or referring the values of the previously defined standard properties: groupId, artifactId, version
• some poperties may override the values of the standard properties - the "package" property. Here it is redefined.

Please note:

• the https://maven.apache.org/archetype/maven-archetype-plugin/advanced-usage.html Apache maven page on archetypes refers just calling "mvn install" in order to publish the artifact in the local repository. This is not enough - use: mvn clean install "archetype:update-local-catalog"
• the https://maven.apache.org/archetype/archetype-models/archetype-descriptor/archetype-descriptor.html Apache maven page states that the proeprties are referred using "property name" expressions. This is not correct - the properties are allowed to be used in the filtered resources, treating them as velocity templates, thus the references are ${property name} and #if, #for, etc. statements could be used there

Answer 2

Not sure I understood correctly. For post processing after project creation you could use the param -Dgoals and invoke your custom plugin.

Am not sure about your requirement, but why cant you do the same during the project generation itself ?

Answer 3

Yes this is possible. From the advanced usage guide for maven archetypes:

If the user wants to customize the generated project even further, a groovy script named archetype-post-generate.groovy can be added in src/main/resources/META-INF/. This script will end up in the generated archetype's META-INF folder and will be executed upon creating a project from this archetype. This groovy script has access to the ArchetypeGenerationRequest object, as well as all the System.getProperties() and all the archetype generation properties the user has specified.