Question

我正在编写一些代码生成maven-plugin。

我需要将我的项目类路径注入到我的插件执行类路径中。

我发现了article。解决方案有效，但很长。也许你们中的某个人知道开箱即用的解决方案。

Answer 1

找到answer！

好的，Pascal是对的，这是基础!!

所以这是最简洁的方法（据我所知）将编译类路径添加到你的插件执行中。

以下是我的code-gen插件中的一些代码示例，它实际上是根据编译的代码生成一些模板代码。所以我首先需要编译代码，然后进行分析，生成一些代码，然后重新编译。

在Mojo类中使用@configurator：

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

请注意javadoc标题中的@configurator行，它对于plexus IOC容器是必不可少的，而不仅仅是另一个注释行。

include-project-dependencies配置程序的实现。我从一些Brian Jackson那里获得了这个非常好的课程，将它添加到插件的源代码中。

/**
 * 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()]);
    }

}

以下是我必须添加的插件的构建部分。

<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>

这是需要它的人的插件的pom.xml。现在应该编译没有问题。（标题有问题，请忽略它）

Answer 2

我采用了这种方法，显然它正在发挥作用：

1 - Mojo类中需要MavenProject参数：

@Parameter(defaultValue = "${project}", required = true, readonly = true)
private MavenProject project;

2 - 然后你可以从项目实例中获取classpath元素：

try {
    Set<URL> urls = new HashSet<>();
    List<String> elements = project.getTestClasspathElements();
                                  //getRuntimeClasspathElements()
                                  //getCompileClasspathElements()
                                  //getSystemClasspathElements()  
    for (String element : elements) {
        urls.add(new File(element).toURI().toURL());
    }

    ClassLoader contextClassLoader = URLClassLoader.newInstance(
            urls.toArray(new URL[0]),
            Thread.currentThread().getContextClassLoader());

    Thread.currentThread().setContextClassLoader(contextClassLoader);

} catch (DependencyResolutionRequiredException e) {
    throw new RuntimeException(e);
} catch (MalformedURLException e) {
    throw new RuntimeException(e);
}

Answer 3

关注此链接....为我的代码做了非常类似的事情......我创建了一个maven-fit-plugin 我为我的插件使用了完全相同的pom.xml，重用了IncludeProjectDependenciesComponentConfigurator

我正在使用maven 2.2.0 如果它可以提供帮助，那么这又是pom

<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
                        http://maven.apache.org/maven-v4_0_0.xsd">

<modelVersion>4.0.0</modelVersion>
<groupId>com.worldcorpservices.plugins</groupId>
<artifactId>maven-fit-plugin</artifactId>
<packaging>maven-plugin</packaging>
<version>1.0-SNAPSHOT</version>
<name>maven-fit-plugin Maven Mojo</name>
<url>http://maven.apache.org</url>

<properties>
    <fitlibrary.version>2.0</fitlibrary.version>
    <maven.version>2.2.0</maven.version>
</properties>


<dependencies>
    <dependency>
        <groupId>org.apache.maven</groupId>
        <artifactId>maven-plugin-api</artifactId>
        <version>2.0</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.7</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>commons-logging</groupId>
        <artifactId>commons-logging</artifactId>
        <version>1.1.1</version>
    </dependency>

    <dependency>
        <groupId>org.fitnesse</groupId>
        <artifactId>fitlibrary</artifactId>
        <version>${fitlibrary.version}</version>
    </dependency>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.12</version>
    </dependency>
    <dependency>
        <groupId>poi</groupId>
        <artifactId>poi</artifactId>
        <version>3.7-20101029</version>
    </dependency>

    <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>
<build>

希望这会有所帮助

RGDS 马可

    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>1.6</source>
                <target>1.6</target>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.codehaus.plexus</groupId>
            <artifactId>plexus-maven-plugin</artifactId>
            <executions>
                <execution>
                    <goals>
                        <goal>descriptor</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>


    </plugins>

</build>

将maven-build-classpath添加到插件执行类路径

3 个答案: