For a sample custom consumer, you can checkout the archiva-consumer-plugin at the archiva sandbox in the SVN repository:
Prior to release 1.4, plexus components are not anymore supported, you must use Spring components.
+* Writing manually
+
+----+
http://svn.apache.org/repos/asf/archiva/sandbox/archiva-consumer-plugin
+----+
<knownContentConsumer>)
[[8]] Start up Archiva again.
+
+* Use the archetype
+
+ Prior to version 1.4-M2, you can use an archetype.
+
++----+
+mvn archetype:generate \
+ -DarchetypeRepository=repo1.maven.org \
+ -DarchetypeGroupId=org.apache.archiva \
+ -DarchetypeArtifactId=archiva-consumer-archetype \
+ -DarchetypeVersion=${project.version}
++----+
+
+ Note: if you want to use a SNAPSHOT version, replace with the following parameter: -DarchetypeRepository=http://vmbuild.apache.org/archiva/repository/snapshots \
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