Set maven property from plugin
I've read some questions here about how to set a property (most of them talked about the version number for an application) from a maven plugin. It seems there's no easy way of doing this and the best solution I found is to have a filter.properties file which is updated from the plugin and used by the main pom file to filter the desired resources.
I tried another solution after I read this from the Maven documentation (Maven filter plugin):
Variables can be included in your resources. These variables, denoted by the ${...} delimiters, can come from the system properties, your project properties, from your filter resources and from the command line.
I found interesting that variabled can be read from system properties. So, I modified my plugin to set a system property like this:
System.setProperty("currentVersion", appCurrentVersion);
However, filtered resources don't seem to read this value. Could anybody tell me what's wrong with this approach?
UPDATE: I'm running my plugin in the validate phase.
Thanks a lot.
Answer
Don't set it as System Property, set it as Maven Project property
// inject the project
@Parameter(defaultValue = "${project}")
private org.apache.maven.project.MavenProject project;
// and in execute(), use it:
project.getProperties().setProperty("currentVersion", appCurrentVersion);
See:
An edit suggested using Properties.put() instead of Properties.setProperty(). While technically, Properties implements Map, this usage is discouraged explicitly in the Properties javadoc.