src/site/apt/examples/sharing-resources.apt.vm

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 Sharing Resources
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 Dennis Lundberg
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 2011-12-23
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Sharing Resources

  The Remote Resources Plugin can also be used to share resources between
  modules in a multi module build. In the following example we have a set of
  files that are used to set up a test environment for a database. We want to
  reuse these resources in several modules in our project.


* Set up a module for the resources to be shared

  Create a new module called <<<shared-resources>>>. Put the files in a
  directory layout like the one below, making sure that your resource files are
  in the <<<src/main/resources>>> directory:

-------------------
shared-resources
|
+- src
|  |
|  `- main
|     |
|     `- resources
|        |
|        +- database.ddl
|        |
|        `- database.sql
|
`- pom.xml
-------------------

  The POM for <<<shared-resources>>> should look like this:

-------------------
<project>
  ...  
  <groupId>org.test</groupId>
  <artifactId>shared-resources</artifactId>
  ...
  <build>
    <plugins>
      <plugin>
        <artifactId>maven-remote-resources-plugin</artifactId>
        <version>${project.version}</version>
        <executions>
          <execution>
            <goals>
              <goal>bundle</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <includes>
            <include>**/*.ddl</include>
            <include>**/*.sql</include>
          </includes>
        </configuration>
      </plugin>
    </plugins>
  </build>
  ...
</project>
------------------- 
 
  This will bundle the shared resources in a JAR file during the
  <<<generate-resources>>> phase. This means that others modules can consume
  these resources in any phase after that. 


* Configure other modules to use the shared module 

  To use the shared resources in another module you need to configure the plugin
  as follows:

-------------------
<project>
  ...
  <groupId>org.test</groupId>
  <artifactId>resource-consumer</artifactId>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-remote-resources-plugin</artifactId>
        <version>${project.version}</version>
        <configuration>
          <resourceBundles>
            <resourceBundle>org.test:shared-resources:\${project.version}</resourceBundle>
          </resourceBundles>
        </configuration>
        <executions>
          <execution>
            <goals>
              <goal>process</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      ...
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>sql-maven-plugin</artifactId>
        <version>1.4</version>
        ...
        <!-- Not showing dependencies or configuration here for brevity -->
        ...
        <executions>
          <execution>
            <id>create-schema</id>
            <phase>process-test-resources</phase>
            <goals>
              <goal>execute</goal>
            </goals>
            <configuration>
              <autocommit>true</autocommit>
              <srcFiles>
                <srcFile>\${project.build.directory}/maven-shared-archive-resources/database.ddl</srcFile>
                <srcFile>\${project.build.directory}/maven-shared-archive-resources/database.sql</srcFile>
              </srcFiles>
            </configuration>
          </execution>
          ...
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
  <dependencies>
    <dependency>
      <groupId>\${project.groupId}</groupId>
      <artifactId>shared-resources</artifactId>
      <version>\${project.version}</version>
    </dependency>
  </dependencies>
</project>
-------------------

  This will retrieve the bundled resources of the <<<shared-resources>>>
  module, process each resource in the bundle and put them in the
  <<<\${project.build.directory}/maven-shared-archive-resources>>> directory of the
  <<<resource-consumer>>> module.

  That means we can use those files in the SQL Maven Plugin to set up the
  database schema using a DDL file, and add some data to the database using an
  SQL file.