Add maven-build-classpath to plugin execution classpath

Question

I am writing some code-gen maven-plugin.

I need my project classpath be injected in to my plugin execution classpath.

I found this article. The solution there works but is quite long. Maybe someone of you know an out of the box solution.

Answer 1

Found the answer!

OK , Pascal is right , here it is for the foundation!!

So here is the cleanest way ( as far as i know ) to add the compile classpath to the execution of you plugin.

Here are some code samples from my code-gen plugin, that is actually generating some template code based on the code compiled. So I needed first the code compiled, then analyzed, generate some code, and then compiled again.

1. Use @configurator in the Mojo class:

   /**  * @goal generate  * @phase process-classes  * @configurator include-project-dependencies  * @requiresDependencyResolution compile+runtime  */ public class CodeGenMojo         extends AbstractMojo {     public void execute()             throws MojoExecutionException     {          // do work....        } } 

   Please pay attention to the @configurator line in the javadoc header, it is essetial for the plexus IOC container and is not just another comment line.

2. The implementation of the include-project-dependencies configurator. There is this very nice class that I took from some Brian Jackson, add it to the source of your plugin.

   /**  * A custom ComponentConfigurator which adds the project's runtime classpath elements  * to the  *  * @author Brian Jackson  * @since Aug 1, 2008 3:04:17 PM  *  * @plexus.component role="org.codehaus.plexus.component.configurator.ComponentConfigurator"  *                   role-hint="include-project-dependencies"  * @plexus.requirement role="org.codehaus.plexus.component.configurator.converters.lookup.ConverterLookup"  *                   role-hint="default"  */ public class IncludeProjectDependenciesComponentConfigurator extends AbstractComponentConfigurator {       private static final Logger LOGGER = Logger.getLogger(IncludeProjectDependenciesComponentConfigurator.class);      public void configureComponent( Object component, PlexusConfiguration configuration,                                     ExpressionEvaluator expressionEvaluator, ClassRealm containerRealm,                                     ConfigurationListener listener )         throws ComponentConfigurationException {          addProjectDependenciesToClassRealm(expressionEvaluator, containerRealm);          converterLookup.registerConverter( new ClassRealmConverter( containerRealm ) );          ObjectWithFieldsConverter converter = new ObjectWithFieldsConverter();          converter.processConfiguration( converterLookup, component, containerRealm.getClassLoader(), configuration,                                         expressionEvaluator, listener );     }      private void addProjectDependenciesToClassRealm(ExpressionEvaluator expressionEvaluator, ClassRealm containerRealm) throws ComponentConfigurationException {         List<String> runtimeClasspathElements;         try {             //noinspection unchecked             runtimeClasspathElements = (List<String>) expressionEvaluator.evaluate("${project.runtimeClasspathElements}");         } catch (ExpressionEvaluationException e) {             throw new ComponentConfigurationException("There was a problem evaluating: ${project.runtimeClasspathElements}", e);         }          // Add the project dependencies to the ClassRealm         final URL[] urls = buildURLs(runtimeClasspathElements);         for (URL url : urls) {             containerRealm.addConstituent(url);         }     }      private URL[] buildURLs(List<String> runtimeClasspathElements) throws ComponentConfigurationException {         // Add the projects classes and dependencies         List<URL> urls = new ArrayList<URL>(runtimeClasspathElements.size());         for (String element : runtimeClasspathElements) {             try {                 final URL url = new File(element).toURI().toURL();                 urls.add(url);                 if (LOGGER.isDebugEnabled()) {                     LOGGER.debug("Added to project class loader: " + url);                 }             } catch (MalformedURLException e) {                 throw new ComponentConfigurationException("Unable to access project dependency: " + element, e);             }         }          // Add the plugin's dependencies (so Trove stuff works if Trove isn't on         return urls.toArray(new URL[urls.size()]);     }  } 

3. Here is the build part of my plugin that you will have to add.

   <modelVersion>4.0.0</modelVersion> <groupId>com.delver</groupId> <artifactId>reference-gen-plugin</artifactId> <name>Reference Code Genration Maven Plugin</name>  <packaging>maven-plugin</packaging> <version>1.2</version>  <url>http://maven.apache.org</url>  <properties>     <maven.version>2.2.1</maven.version> </properties>  <build>     <plugins>         <plugin>             <groupId>org.codehaus.plexus</groupId>             <artifactId>plexus-maven-plugin</artifactId>             <executions>                 <execution>                     <goals>                         <goal>descriptor</goal>                     </goals>                 </execution>             </executions>         </plugin>     </plugins> </build> <dependencies>      <dependency>         <groupId>org.apache.maven</groupId>         <artifactId>maven-artifact</artifactId>         <version>${maven.version}</version>     </dependency>     <dependency>         <groupId>org.apache.maven</groupId>         <artifactId>maven-plugin-api</artifactId>         <version>${maven.version}</version>     </dependency>     <dependency>         <groupId>org.apache.maven</groupId>         <artifactId>maven-project</artifactId>         <version>${maven.version}</version>     </dependency>     <dependency>         <groupId>org.apache.maven</groupId>         <artifactId>maven-model</artifactId>         <version>${maven.version}</version>     </dependency>     <dependency>         <groupId>org.apache.maven</groupId>         <artifactId>maven-core</artifactId>         <version>2.0.9</version>     </dependency>  </dependencies> 

   Here is the pom.xml of the plugin for these who need it. Should compile wihtout a problem now. ( something wrong with the header, so ignore it )