maven-archetype-plugin/src/site/apt/specification/archetype-catalog.apt

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 Archetype Catalog
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 Raphaël Piéroni
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 2011-09-30
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~~ "License"); you may not use this file except in compliance
~~ with the License.  You may obtain a copy of the License at
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~~ software distributed under the License is distributed on an
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~~ KIND, either express or implied.  See the License for the
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~~ NOTE: For help with the syntax of this file, see:
~~ http://maven.apache.org/doxia/references/apt-format.html


How does the Archetype Plugin know about archetypes?

    Knowledge about archetypes is stored in catalogs.

    The catalogs are xml files: see the {{{../../archetype-models/archetype-catalog/archetype-catalog.html}reference documentation}}.

    The Archetype Plugin comes bundled with an internal catalog.
    This one is used by default.

    The Archetype Plugin can use catalogs from local filesystem and from HTTP
    connections.

* Catalog file explained

    A catalog is an xml file with such content:

+---
<?xml version="1.0" encoding="UTF-8"?>
<archetype-catalog  xmlns="http://maven.apache.org/plugins/maven-archetype-plugin/archetype-catalog/1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/plugins/maven-archetype-plugin/archetype-catalog/1.0.0 http://maven.apache.org/xsd/archetype-catalog-1.0.0.xsd">
  <archetypes>
    <archetype>
[1]    <groupId>org.appfuse.archetypes</groupId>
[2]    <artifactId>appfuse-basic-jsf</artifactId>
[3]    <version>2.0</version>
[4]    <repository>http://static.appfuse.org/releases</repository>
[5]    <description>AppFuse archetype for creating a web application with Hibernate, Spring and JSF</description>
    </archetype>
    ...
  </archetypes>
</archetype-catalog>
+---

    [[1]] The groupId of the archetype. <<REQUIRED>>

    [[2]] The artifactId of the archetype. <<REQUIRED>>

    [[3]] The version of the archetype. <<<RELEASE>>> is a valid version. <<REQUIRED>>

    [[4]] The repository where to find the archetype. <<OPTIONAL>>. When
          omitted, the archetype is searched for in the repository where the catalog
          comes from.

    [[5]] The description of the archetype. <<OPTIONAL>>


* Archetype selection explained

    During the creation of a project from an archetype, the Archetype Plugin
    asks the user to choose an archetype from a list containing the archetypes
    from each of the provided catalogs (yes, there may be many).

    For each archetype in the list, the Archetype Plugin shows a line like:

+---
1: internal -> appfuse-basic-jsf (AppFuse archetype for creating a web application with Hibernate, Spring and JSF)
+---

    * <<<1:>>> The index of the archetype in the aggregated list (starting from
      1).

    * <<<internal>>> The name of the catalog where the archetype originates from.

    * <<<appfuse-basic-jsf>>> The artifactId of the archetype.

    * <<<(AppFuse archetype...)>>> The description of the archetype as found in
      the catalog.


* Creating a catalog file

    At the end of the <<<create-from-project>>> behaviour, the Archetype Plugin
    installs/deploys the archetype, and updates the local/remote catalog.

    The <<<crawl-repository>>> goal is used to create a catalog file by crawling
    a Maven repository located in the filesystem.

* Location of catalog files

    The Archetype Plugin knows by default about its internal catalog. It also knows
    about the <<<local>>> and <<<remote>>> catalogs.

    <<<local>>> represents the <<<~/.m2/archetype-catalog.xml>>> catalog file.

    <<<remote>>> represents the <<<https://repo.maven.apache.org/maven2/archetype-catalog.xml>>> catalog file.

    The Archetype Plugin can also read catalogs from filesystem/HTTP by
    providing the path/URL of a catalog file or of a directory containing an
    <<<archetype-catalog.xml>>> file.