如何解析/解压缩/解压缩由Nexus生成的Maven存储库索引

Question

我已经从http://mirrors.ibiblio.org/pub/mirrors/maven2/dot-index/nexus-maven-repository-index.gz下载了为Maven Central生成的索引.

我想列出这些索引文件中的工件信息(例如groupId,artifactId,version).我已经读过,有一个高级API.似乎我必须使用以下maven依赖项.但是,我不知道使用什么入口点(哪个类？)以及如何使用它来访问这些文件:

<dependency>
    <groupId>org.sonatype.nexus</groupId>
    <artifactId>nexus-indexer</artifactId>
    <version>3.0.4</version>
</dependency>

Answer 1

快来看看https://github.com/cstamas/maven-indexer-examples项目.

简而言之:您不需要手动下载GZ/ZIP(新/旧格式),索引器会为您完成这项工作(此外,如果可能,它也将为您处理增量更新).

GZ是"新"格式,独立于Lucene索引格式(因此,独立于Lucene版本)仅包含数据,而ZIP是"旧"格式,这实际上是简单的Lucene 2.4.x索引压缩.目前没有数据内容发生变化,但计划在未来发生.

正如我所说,两者之间没有数据内容差异,但是某些字段(如您所注意到的)是索引但未存储在索引中,因此,如果您使用ZIP格式,您将可以搜索它们,但无法检索.

Answer 2

该https://github.com/cstamas/maven-indexer-examples已经过时了.构建失败(测试不通过).

Nexus Indexer已经移动并包含了这些示例:https: //github.com/apache/maven-indexer/tree/master/indexer-examples

这构建,代码工作.

如果您想自己推出,这是一个简化版本:

Maven的:

<dependencies>
    <dependency>
        <groupId>org.apache.maven.indexer</groupId>
        <artifactId>indexer-core</artifactId>
        <version>6.0-SNAPSHOT</version>
        <scope>compile</scope>
    </dependency>

    <!-- For ResourceFetcher implementation, if used -->
    <dependency>
        <groupId>org.apache.maven.wagon</groupId>
        <artifactId>wagon-http-lightweight</artifactId>
        <version>2.3</version>
        <scope>compile</scope>
    </dependency>

    <!-- Runtime: DI, but using Plexus Shim as we use Wagon -->
    <dependency>
        <groupId>org.eclipse.sisu</groupId>
        <artifactId>org.eclipse.sisu.plexus</artifactId>
        <version>0.2.1</version>
    </dependency>
    <dependency>
        <groupId>org.sonatype.sisu</groupId>
        <artifactId>sisu-guice</artifactId>
        <version>3.2.4</version>
    </dependency>

Java的:

public IndexToGavMappingConverter(File dataDir, String id, String url)
    throws PlexusContainerException, ComponentLookupException, IOException
{
    this.dataDir = dataDir;

    // Create Plexus container, the Maven default IoC container.
    final DefaultContainerConfiguration config = new DefaultContainerConfiguration();
    config.setClassPathScanning( PlexusConstants.SCANNING_INDEX );
    this.plexusContainer = new DefaultPlexusContainer(config);

    // Lookup the indexer components from plexus.
    this.indexer = plexusContainer.lookup( Indexer.class );
    this.indexUpdater = plexusContainer.lookup( IndexUpdater.class );
    // Lookup wagon used to remotely fetch index.
    this.httpWagon = plexusContainer.lookup( Wagon.class, "http" );

    // Files where local cache is (if any) and Lucene Index should be located
    this.centralLocalCache = new File( this.dataDir, id + "-cache" );
    this.centralIndexDir = new File( this.dataDir,   id + "-index" );

    // Creators we want to use (search for fields it defines).
    // See https://maven.apache.org/maven-indexer/indexer-core/apidocs/index.html?constant-values.html
    List<IndexCreator> indexers = new ArrayList();
    // https://maven.apache.org/maven-indexer/apidocs/org/apache/maven/index/creator/MinimalArtifactInfoIndexCreator.html
    indexers.add( plexusContainer.lookup( IndexCreator.class, "min" ) );
    // https://maven.apache.org/maven-indexer/apidocs/org/apache/maven/index/creator/JarFileContentsIndexCreator.html
    //indexers.add( plexusContainer.lookup( IndexCreator.class, "jarContent" ) );
    // https://maven.apache.org/maven-indexer/apidocs/org/apache/maven/index/creator/MavenPluginArtifactInfoIndexCreator.html
    //indexers.add( plexusContainer.lookup( IndexCreator.class, "maven-plugin" ) );

    // Create context for central repository index.
    this.centralContext = this.indexer.createIndexingContext(
            id + "Context", id, this.centralLocalCache, this.centralIndexDir,
            url, null, true, true, indexers );
}


    final IndexSearcher searcher = this.centralContext.acquireIndexSearcher();
    try
    {
        final IndexReader ir = searcher.getIndexReader();
        Bits liveDocs = MultiFields.getLiveDocs(ir);
        for ( int i = 0; i < ir.maxDoc(); i++ )
        {
            if ( liveDocs == null || liveDocs.get( i ) )
            {
                final Document doc = ir.document( i );
                final ArtifactInfo ai = IndexUtils.constructArtifactInfo( doc, this.centralContext );

                if (ai == null)
                    continue;
                if (ai.getSha1() == null)
                    continue;
                if (ai.getSha1().length() != 40)
                    continue;
                if ("javadoc".equals(ai.getClassifier()))
                    continue;
                if ("sources".equals(ai.getClassifier()))
                    continue;

                out.append(StringUtils.lowerCase(ai.getSha1())).append(' ');
                out.append(ai.getGroupId()).append(":");
                out.append(ai.getArtifactId()).append(":");
                out.append(ai.getVersion()).append(":");
                out.append(StringUtils.defaultString(ai.getClassifier()));
                out.append('\n');
            }
        }
    }
    finally
    {
        this.centralContext.releaseIndexSearcher( searcher );
    }

我们在Windup项目中使用它- JBoss迁移工具.