从 Plexus 获取 Maven 实例答案

【问题标题】：Obtaining a Maven-Instance from Plexus从 Plexus 获取 Maven 实例
【发布时间】：2018-02-04 07:30:08
【问题描述】：

我目前正在尝试让 PlexusContainer 在 maven 或 eclipse 执行上下文之外为我提供一个初始化的 Maven-instance。

为此，我有以下代码（简化）：

PlexusContainer container = null;
try {
    container = new DefaultPlexusContainer();
    container.lookup(MavenResolutionTask.class).run();
    container.dispose();
} catch (Exception e) {
    e.printStackTrace();
}

// --- MavenResolutionTask.java:

@Component(role = MavenResolutionTask.class)
// ResolutionTask is an abstract class 
// implementing Runnable and extending CompletableFuture
public class MavenResolutionTask extends ResolutionTask {

    @Requirement
    private Maven maven;
}

鉴于我在我的 pom.xml 中有标准的 plexus-component-metadata:process-classes 插件执行，如果它像这样工作我会很高兴的。

不幸的是，运行此代码会导致 LookupException，原因如下（为简洁起见，省略了堆栈跟踪）：

WARN Sisu - Error injecting: org.apache.maven.project.DefaultProjectBuildingHelper
com.google.inject.ProvisionException: Guice provision errors:

1) No implementation for org.apache.maven.repository.RepositorySystem was bound.
  while locating org.apache.maven.project.DefaultProjectBuildingHelper

WARN Sisu - Error injecting: org.apache.maven.project.DefaultProjectBuilder
com.google.inject.ProvisionException: Guice provision errors:

1) No implementation for org.apache.maven.repository.RepositorySystem was bound.
  while locating org.apache.maven.project.DefaultProjectBuildingHelper
  at ClassRealm[plexus.core, parent: null]
  at ClassRealm[plexus.core, parent: null]
  while locating org.apache.maven.project.ProjectBuildingHelper
  while locating org.apache.maven.project.DefaultProjectBuilder

...

为了修复丢失的绑定并避免自己不得不手动注册 maven 的完整依赖关系图的麻烦，我尝试将包含在我的依赖项中的组件描述符与为我的应用程序生成的组件描述符合并。

为此，我将所有依赖项复制到 target/dependency 并运行一些 shell 脚本以获取包含 components.xml 的所有依赖项的列表。
我将这些依赖项传递给dependency:unpack 的执行，然后将提取的位置传递给元数据合并器，如下所示：

<plugin>
    <groupId>org.codehaus.plexus</groupId>
    <artifactId>plexus-component-metadata</artifactId>
    <version>1.7.1</version>
    <executions>
        <execution>
            <id>process-classes</id>
            <goals>
                <goal>generate-metadata</goal>
            </goals>
        </execution>
        <execution>
            <id>process-test-classes</id>
            <goals>
                <goal>generate-test-metadata</goal>
            </goals>
        </execution>
        <execution>
            <id>merge-descriptors</id>
            <phase>process-classes</phase>
            <goals>
                <goal>merge-metadata</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <output>${plexus.outputFile}</output>
        <descriptors>
            <descriptor>${plexus.outputFile}</descriptor>
            <!--./aether-transport-wagon-1.1.0.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/aether-transport-wagon/META-INF/plexus/components.xml</descriptor>
            <!--./maven-aether-provider-3.1.0.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/maven-aether-provider/META-INF/plexus/components.xml</descriptor>
            <!--./maven-artifact-manager-2.2.1.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/maven-artifact-manager/META-INF/plexus/components.xml</descriptor>
            <!--./maven-core-3.1.1.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/maven-core/META-INF/plexus/components.xml</descriptor>
            <!--./maven-model-builder-3.1.0.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/maven-model-builder/META-INF/plexus/components.xml</descriptor>
            <!--./maven-plugin-registry-2.2.1.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/maven-plugin-registry/META-INF/plexus/components.xml</descriptor>
            <!--./maven-profile-2.2.1.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/maven-profile/META-INF/plexus/components.xml</descriptor>
            <!--./maven-project-2.2.1.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/maven-project/META-INF/plexus/components.xml</descriptor>
            <!--./maven-settings-builder-3.1.1.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/maven-settings-builder/META-INF/plexus/components.xml</descriptor>
            <!--./org.eclipse.sisu.plexus-0.0.0.M2a.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/sisu-plexus/META-INF/plexus/components.xml</descriptor>
            <!--./plexus-cipher-1.4.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/plexus-cipher/META-INF/plexus/components.xml</descriptor>
            <!--./plexus-interactivity-api-1.0-alpha-6.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/plexus-interactivity-api/META-INF/plexus/components.xml</descriptor>
            <!--./plexus-sec-dispatcher-1.3.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/plexus-sec-dispatcher/META-INF/plexus/components.xml</descriptor>
            <!--./wagon-ssh-1.0.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/wagon-ssh/META-INF/plexus/components.xml</descriptor>
            <!--./wagon-ssh-common-1.0.jar.d/META-INF/plexus/components.xml-->
            <descriptor>${project.build.directory}/extracted-sources/wagon-ssh-common/META-INF/plexus/components.xml</descriptor>
        </descriptors>
    </configuration>
</plugin>

不幸的是，错误消息仍然存在所以我想我的问题是：如何轻松地从 Plexus 获取 Maven 实例？

附：为了完整起见，我目前正在使用以下依赖项：

[INFO] com.github.vogel612:dependency-analyzer:jar:0.0.1
[INFO] +- org.projectlombok:lombok:jar:1.16.16:compile
[INFO] +- commons-cli:commons-cli:jar:1.4:compile
[INFO] +- org.slf4j:slf4j-simple:jar:1.7.16:compile
[INFO] |  \- org.slf4j:slf4j-api:jar:1.7.16:compile
[INFO] +- org.codehaus.plexus:plexus-utils:jar:3.0.24:compile
[INFO] +- org.eclipse.aether:aether-api:jar:1.1.0:compile
[INFO] +- org.eclipse.aether:aether-util:jar:1.1.0:compile
[INFO] +- org.eclipse.aether:aether-impl:jar:1.1.0:compile
[INFO] |  \- org.eclipse.aether:aether-spi:jar:1.1.0:compile
[INFO] +- org.eclipse.aether:aether-connector-basic:jar:1.1.0:compile
[INFO] +- org.eclipse.aether:aether-transport-file:jar:1.1.0:compile
[INFO] +- org.eclipse.aether:aether-transport-http:jar:1.1.0:compile
[INFO] |  +- org.apache.httpcomponents:httpclient:jar:4.3.5:compile
[INFO] |  |  +- org.apache.httpcomponents:httpcore:jar:4.3.2:compile
[INFO] |  |  \- commons-codec:commons-codec:jar:1.6:compile
[INFO] |  \- org.slf4j:jcl-over-slf4j:jar:1.6.2:compile
[INFO] +- org.eclipse.aether:aether-transport-wagon:jar:1.1.0:compile
[INFO] |  \- org.apache.maven.wagon:wagon-provider-api:jar:1.0:compile
[INFO] +- org.apache.maven:maven-aether-provider:jar:3.1.0:compile
[INFO] |  +- org.apache.maven:maven-model:jar:3.1.0:compile
[INFO] |  +- org.apache.maven:maven-model-builder:jar:3.1.0:compile
[INFO] |  +- org.apache.maven:maven-repository-metadata:jar:3.1.0:compile
[INFO] |  +- org.eclipse.sisu:org.eclipse.sisu.plexus:jar:0.0.0.M2a:compile
[INFO] |  |  +- javax.enterprise:cdi-api:jar:1.0:compile
[INFO] |  |  |  +- javax.annotation:jsr250-api:jar:1.0:compile
[INFO] |  |  |  \- javax.inject:javax.inject:jar:1:compile
[INFO] |  |  +- com.google.guava:guava:jar:10.0.1:compile
[INFO] |  |  |  \- com.google.code.findbugs:jsr305:jar:1.3.9:compile
[INFO] |  |  +- org.sonatype.sisu:sisu-guice:jar:no_aop:3.1.0:compile
[INFO] |  |  |  \- aopalliance:aopalliance:jar:1.0:compile
[INFO] |  |  \- org.eclipse.sisu:org.eclipse.sisu.inject:jar:0.0.0.M2a:compile
[INFO] |  |     \- asm:asm:jar:3.3.1:compile
[INFO] |  \- org.codehaus.plexus:plexus-component-annotations:jar:1.5.5:compile
[INFO] +- org.apache.maven.wagon:wagon-ssh:jar:1.0:compile
[INFO] |  +- com.jcraft:jsch:jar:0.1.44-1:compile
[INFO] |  \- org.apache.maven.wagon:wagon-ssh-common:jar:1.0:compile
[INFO] |     \- org.codehaus.plexus:plexus-interactivity-api:jar:1.0-alpha-6:compile
[INFO] +- org.apache.maven:maven-core:jar:3.1.1:compile
[INFO] |  +- org.apache.maven:maven-settings:jar:3.1.1:compile
[INFO] |  +- org.apache.maven:maven-settings-builder:jar:3.1.1:compile
[INFO] |  +- org.apache.maven:maven-artifact:jar:3.1.1:compile
[INFO] |  +- org.apache.maven:maven-plugin-api:jar:3.1.1:compile
[INFO] |  +- org.codehaus.plexus:plexus-interpolation:jar:1.19:compile
[INFO] |  +- org.codehaus.plexus:plexus-classworlds:jar:2.5.1:compile
[INFO] |  \- org.sonatype.plexus:plexus-sec-dispatcher:jar:1.3:compile
[INFO] |     \- org.sonatype.plexus:plexus-cipher:jar:1.4:compile
[INFO] \- org.apache.maven:maven-project:jar:2.2.1:compile
[INFO]    +- org.apache.maven:maven-profile:jar:2.2.1:compile
[INFO]    +- org.apache.maven:maven-artifact-manager:jar:2.2.1:compile
[INFO]    |  \- backport-util-concurrent:backport-util-concurrent:jar:3.1:compile
[INFO]    +- org.apache.maven:maven-plugin-registry:jar:2.2.1:compile
[INFO]    \- org.codehaus.plexus:plexus-container-default:jar:1.0-alpha-9-stable-1:compile
[INFO]       +- junit:junit:jar:3.8.1:compile
[INFO]       \- classworlds:classworlds:jar:1.1-alpha-2:compile

【问题讨论】：

你想达到什么目的或者你想解决什么问题？您能否详细说明您的问题到底是什么？
我想解决一个项目的所有依赖。除了解析他们的名字之外，我还需要他们的远程 URL。因为我需要做的不仅仅是 maven，调用 mvn 不是最好的选择，所以我想把它委托给 maven-core
我已经了解到您正在尝试解决项目的依赖关系，但目的是什么？为什么需要名字？你说的名字是什么意思？ artifactId ?以及什么样的远程 URL？请详细说明您遇到的问题？
远程 URL 我的意思是 dependency:get 将从中获取 dep 的实际远程存储库位置。名称旨在作为坐标的简写...目的是获得一个包含附加信息（包括许可证信息）的依赖项列表，这些信息可以合并到一个 EXCEL 列表中，出于法律原因而保留，最终目标是尽可能多地自动化尽可能使用法律术语。
看看：mojohaus.org/license-maven-plugin

标签： java maven dependency-injection plexus

【解决方案1】：

仔细阅读错误消息可能会有所帮助：

缺少的组件是org.apache.maven.repository.RepositorySystem 而不是org.eclipse.aether.RepositorySystem。虽然前者已包含在内，但后者仅存在于 org.apache.maven:maven-compat 中。

将它添加到依赖项（包括它的组件定义）可以解决这里的直接问题。中间结果目前是NoClassDefFoundError对应Lorg/apache/maven/artifact/transform/ArtifactTransformationManager，实际使用正确版本的依赖即可解决。

作为最后一步，现在需要注册org.eclipse.aether.RepositorySystem 的一个实例和一个org.eclipse.aether.impl.RemoteRepositoryManager 的实例，这可以使用以下代码来完成：

final ServiceLocator serviceLocator = MavenRepositorySystemUtils.newServiceLocator()
        .addService(RepositoryConnectorFactory.class, BasicRepositoryConnectorFactory.class)
        .addService(TransporterFactory.class, FileTransporterFactory.class)
        .addService(TransporterFactory.class, HttpTransporterFactory.class);

 // ...
container.addComponent(serviceLocator.lookup(RepositorySystem.class)
    , RepositorySystem.class
    , "default");
container.addComponent(serviceLocator.lookup(RemoteRepositoryManager.class)
    , RemoteRepositoryManager.class
    , "default");

现在我们终于可以拥有一个 maven 实例了。

【讨论】：