VersionResolutionException:未能解决版本发布

Question

突然，Maven无法使用版本RELEASE解决依赖关系。

例如：-

<dependency>
            <groupId>com.google.api-ads</groupId>
            <artifactId>ads-lib</artifactId>
            <version>RELEASE</version>
</dependency>

在maven安装时，我得到以下错误：-

 Caused by: org.eclipse.aether.collection.DependencyCollectionException: Failed to collect dependencies at com.google.api-ads:ads-lib:jar:RELEASE
    at org.eclipse.aether.internal.impl.DefaultDependencyCollector.collectDependencies(DefaultDependencyCollector.java:291)
    at org.eclipse.aether.internal.impl.DefaultRepositorySystem.collectDependencies(DefaultRepositorySystem.java:316)
    at org.apache.maven.project.DefaultProjectDependenciesResolver.resolve(DefaultProjectDependenciesResolver.java:172)
    ... 24 more
Caused by: org.eclipse.aether.resolution.ArtifactDescriptorException: Failed to read artifact descriptor for com.google.api-ads:ads-lib:jar:RELEASE
    at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.loadPom(DefaultArtifactDescriptorReader.java:245)
    at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.readArtifactDescriptor(DefaultArtifactDescriptorReader.java:198)
    at org.eclipse.aether.internal.impl.DefaultDependencyCollector.resolveCachedArtifactDescriptor(DefaultDependencyCollector.java:535)
    at org.eclipse.aether.internal.impl.DefaultDependencyCollector.getArtifactDescriptorResult(DefaultDependencyCollector.java:519)
    at org.eclipse.aether.internal.impl.DefaultDependencyCollector.processDependency(DefaultDependencyCollector.java:409)
    at org.eclipse.aether.internal.impl.DefaultDependencyCollector.processDependency(DefaultDependencyCollector.java:363)
    at org.eclipse.aether.internal.impl.DefaultDependencyCollector.process(DefaultDependencyCollector.java:351)
    at org.eclipse.aether.internal.impl.DefaultDependencyCollector.collectDependencies(DefaultDependencyCollector.java:254)
    ... 26 more
Caused by: org.eclipse.aether.resolution.VersionResolutionException: Failed to resolve version for com.google.api-ads:ads-lib:jar:RELEASE: Could not find metadata com.google.api-ads:ads-lib/maven-metadata.xml in local (C:\Users\ashwani.kumar\.m2\repository)
    at org.apache.maven.repository.internal.DefaultVersionResolver.resolveVersion(DefaultVersionResolver.java:300)
    at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.loadPom(DefaultArtifactDescriptorReader.java:231)
    ... 33 more
Caused by: org.eclipse.aether.transfer.MetadataNotFoundException: Could not find metadata com.google.api-ads:ads-lib/maven-metadata.xml in local (C:\Users\ashwani.kumar\.m2\repository)
    at org.eclipse.aether.internal.impl.DefaultMetadataResolver.resolve(DefaultMetadataResolver.java:247)
    at org.eclipse.aether.internal.impl.DefaultMetadataResolver.resolveMetadata(DefaultMetadataResolver.java:205)
    at org.apache.maven.repository.internal.DefaultVersionResolver.resolveVersion(DefaultVersionResolver.java:237)
    ... 34 more

另外，我无法看到依赖项https://mvnrepository.com/artifact/com.google.api-ads/ads-lib的任何发布版本

在进一步的探索中，我发现了https://www.baeldung.com/maven-dependency-latest-version一篇文章

根据它：-

废弃语法 Maven2还提供了两个特殊的元版本值来实现结果:最新版和发布版。 然而，这种遗留的升级方法在CI需要重现性的情况下造成了不可预测性。因此，在Maven3中，它们已被完全删除： 为了可重复构建，Maven 3.x不再支持在POM中使用这些元版本 除了版本的Maven插件，还有其他解决方案吗？

Answer 1

TL;DR

尝试更新本地元数据，将-U arg传递给maven命令行：

 mvn -U install

在我的例子中，maven认为本地元数据是最新的，因此跳过了远程元数据的下载。

我在调试日志中看到了它：

[DEBUG] Skipped remote request for org.dbunit:dbunit/maven-metadata.xml locally installed metadata up-to-date.

但可悲的是，这不是真的。本地元数据如下：

<metadata>
  <groupId>org.dbunit</groupId>
  <artifactId>dbunit</artifactId>
  <versioning>
    <versions>
      <version>2.7.3</version>
    </versions>
    <lastUpdated>20220811072909</lastUpdated>
  </versioning>
</metadata>

而远程元数据是

<metadata modelVersion="1.1.0">
    <groupId>org.dbunit</groupId>
    <artifactId>dbunit</artifactId>
    <versioning>
        <latest>2.7.3</latest>
        <release>2.7.3</release>
        <versions>
            <version>2.2</version>
            <version>2.2.1</version>
            <version>2.2.2</version>
            <version>2.2.3</version>
            <version>2.3.0</version>
            <version>2.4.0</version>
            <version>2.4.1</version>
            <version>2.4.2</version>
            <version>2.4.3</version>
            <version>2.4.4</version>
            <version>2.4.5</version>
            <version>2.4.6</version>
            <version>2.4.7</version>
            <version>2.4.8</version>
            <version>2.4.9</version>
            <version>2.5.0</version>
            <version>2.5.1</version>
            <version>2.5.2</version>
            <version>2.5.3</version>
            <version>2.5.4</version>
            <version>2.6.0</version>
            <version>2.7.0</version>
            <version>2.7.1</version>
            <version>2.7.2</version>
            <version>2.7.3</version>
        </versions>
        <lastUpdated>20220213055459</lastUpdated>
    </versioning>
</metadata>

如您所见，远程元数据包含更多版本以及<release>和<latest>标记。当地没有包含它。

我想这就是为什么maven不能再检测到RELEASE版本的问题。但是LATEST版本很奇怪，即使元数据中没有<latest>标记。maven似乎通过查看release标记来确定RELEASE版本，但是对于LATEST版本，它会搜索<versions>列表。