#hbase-archetypes ##Overview The hbase-archetypes subproject of hbase provides an infrastructure for creation and maintenance of Maven archetypes^[1](#f1) pertinent to HBase. Upon deployment to the archetype catalog^[2](#f2) of the central Maven repository^[3](#f3), these archetypes may be used by end-user developers to autogenerate completely configured Maven projects (including fully-functioning sample code) through invocation of the `archetype:generate` goal of the maven-archetype-plugin^[4](#f4). ##Notes for contributors and committers to the HBase project ####The structure of hbase-archetypes The hbase-archetypes project contains a separate subproject for each archetype. The top level components of such a subproject comprise a complete, standalone exemplar Maven project containing: - a `src` directory with sample, fully-functioning code in the `./main` and `./test` subdirectories, - a `pom.xml` file defining all required dependencies, and - any additional resources required by the exemplar project. For example, the components of the hbase-client-project consist of (a) sample code `./src/main/.../HelloHBase.java` and `./src/test/.../TestHelloHBase.java`, (b) a `pom.xml` file establishing dependency upon hbase-client and test-scope dependency upon hbase-testing-util, and (c) a `log4j.properties` resource file. ####How archetypes are created during the hbase install process During the `mvn install` process, all standalone exemplar projects in the `hbase-archetypes` subdirectory are first packaged/tested/installed, and then the following steps are executed in `hbase-archetypes/hbase-archetype-builder` (via the `pom.xml`, bash scripts, and xsl templates in that subdirectory): 1. For each exemplar project, resources are copied (via maven-resources-plugin) and transformed (via xml-maven-plugin xslt functionality) to the exemplar project's `./target/build-archetype` subdirectory^[5](#f5). 2. The script `createArchetypes.sh` is executed to invoke the maven-archetype-plugin's `create-from-project` goal within each exemplar project's `./target/build-archetype` subdirectory. For each exemplar project, this creates a corresponding Maven archetype in the `./target/build-archetype/target/generate-sources/archetype` subdirectory. (Note that this step always issues two platform-encoding warnings per archetype, due to hard-wired behavior of the maven-archetype-plugin^[6](#f6).) 3. The `pom.xml` file of each newly-created archetype is copied (via maven-resources-plugin) and transformed (via xml-maven-plugin xslt functionality)^[7](#f7). 4. The script `installArchetypes.sh` is executed to install each archetype into the local Maven repository, ready for deployment to the central Maven repository. (Note that installation of an archetype automatically includes invocation of integration-testing prior to install, which performs a test generation of a project from the archetype.) ####How to add a new archetype to the hbase-archetypes collection 1. Create a new subdirectory in `hbase-archetypes`, populated with a completely configured Maven project, which will serve as the exemplar project of the new archetype. (It may be most straightforward to simply copy the `src` and `pom.xml` components from one of the existing exemplar projects, replace the `src/main` and `src/test` code, and modify the `pom.xml` file's ``, ``,` `, and `` elements.) 2. Modify the `hbase-archetype-builder/pom.xml` file: (a) add the new exemplar project to the `` element, and (b) add appropriate `` elements and `` elements within the `` elements (using the existing entries from already-existing exemplar projects as a guide). 3. Add appropriate entries for the new exemplar project to the `createArchetypes.sh` and `installArchetypes.sh` scripts in the `hbase-archetype-builder` subdirectory (using the existing entries as a guide). ####How to do additional testing/inspection of an archetype in this collection Although integration-testing (which is automatically performed for each archetype during the install process) already performs test generation of a project from an archetype, it may often be advisable to do further manual testing of a newly built and installed archetype, particularly to examine and test a project generated from the archetype (emulating the end-user experience of utilizing the archetype). Upon completion of the install process outlined above, all archetypes will have been installed in the local Maven repository and can be tested locally by executing the following: `mvn archetype:generate -DarchetypeCatalog=local` This displays a numbered list of all locally-installed archetypes for the user to choose from for generation of a new Maven project. ##Footnotes: 1 -- [Maven Archetype ](http://maven.apache.org/archetype/index.html) ("About" page). -- [↩](#a1) 2 -- [Maven Archetype Catalog ](http://repo1.maven.org/maven2/archetype-catalog.xml) (4MB+ xml file). -- [↩](#a2) 3 -- [Maven Central Repository](http://search.maven.org/) (search engine). -- [↩](#a3) 4 -- [Maven Archetype Plugin - archetype:generate ](http://maven.apache.org/archetype/maven-archetype-plugin/generate-mojo.html). -- [↩](#a4) 5 -- Prior to archetype creation, each exemplar project's `pom.xml` is transformed as follows to make it into a standalone project: RESOURCE FILTERING (a) replaces `${project.version}` with the literal value of the current project.version and (b) replaces `${compileSource}` with the literal value of the version of Java that is being used for compilation; XSLT TRANSFORMATION (a) copies `` and `` subelements of `` to make them child elements of the root element, and (b) removes the `` and `` elements. -- [↩](#a5) 6 -- For an explanation of the platform-encoding warning issued during maven-archetype-plugin processing, see the first answer to [this stackoverflow posting](http://stackoverflow.com/a/24161287/4112172). -- [↩](#a6) 7 -- Prior to archetype installation, each archetype's `pom.xml` is transformed as follows: a `` subelement with value 'UTF-8' is added to the `` element. This prevents platform-encoding warnings from being issued when an end-user generates a project from the archetype. -- [↩](#a7)