Question

我生成默认的快速入门Maven示例，并输入mvn checkstyle:checkstyle，它总是尝试使用最新的SNAPSHOT版本。可能是我的Nexus服务器出错了，但是如何在Maven 2的命令行中设置插件的版本，比如2.5用于checkstyle而不是2.6-SNAPSHOT？

C:\HelloWorld>mvn checkstyle:checkstyle
[INFO] Scanning for projects...
[INFO] Searching repository for plugin with prefix: 'checkstyle'.
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Error building POM (may not be this project's POM).

Project ID: org.apache.maven.plugins:maven-checkstyle-plugin

Reason: Error getting POM for 'org.apache.maven.plugins:maven-checkstyle-plugin' from  the repository: Failed to resolve artifact, possibly due to a repository list that is not appropriately equipped for this artifact's metadata.
  org.apache.maven.plugins:maven-checkstyle-plugin:pom:2.6-SNAPSHOT

from the specified remote repositories:
  nexus (http://localhost:9081/nexus/content/groups/public)

for project org.apache.maven.plugins:maven-checkstyle-plugin

我想它可能是mvn checkstyle:2.5:checkstyle，但遗憾的是它不是。

当然，如果我在pom.xml中设置构建依赖，它会起作用，但我想看看命令行如何工作。

Answer 1

如果您不想运行本地存储库中安装的最新版本的插件，则需要设置版本号。为此，您需要以下列形式指定完全合格的目标：

mvn groupID:artifactID:version:goal

所以在你的情况下：

mvn org.apache.maven.plugins:maven-checkstyle-plugin:2.5:checkstyle

Answer 2

mvn org.apache.maven.plugins:maven-site-plugin:3.7.1:site

Answer 3

您也可以使用：

mvn {your groupId}：{your artifactId}：{your version}：{your goal}

Answer 4

我对新版maven（3.3.9）的体验略有不同。如果我没有在离线模式下运行maven，它将始终用于远程仓库，无论我在本地仓库中拥有什么。如果它找到一个更新的版本（基于maven-metadata.xml），它将下载并使用该版本。更重要的是，它会同时扫描多个回购：

[INFO] ------------------------------------------------------------------------
[DEBUG] Resolving plugin version for com.phoenixnap.oss:springmvc-raml-plugin
[DEBUG] Could not find metadata com.phoenixnap.oss:springmvc-raml-plugin/maven-metadata.xml in local (/home/yuranos/.m2/repository)
[DEBUG] Using transporter WagonTransporter with priority -1.0 for https://repo.spring.io/libs-milestone
[DEBUG] Using transporter WagonTransporter with priority -1.0 for https://repo.spring.io/milestone
[DEBUG] Using transporter WagonTransporter with priority -1.0 for https://repo.maven.apache.org/maven2
[DEBUG] Using transporter WagonTransporter with priority -1.0 for https://repo.spring.io/snapshot
[DEBUG] Using connector BasicRepositoryConnector with priority 0.0 for https://repo.spring.io/libs-milestone
[DEBUG] Using connector BasicRepositoryConnector with priority 0.0 for https://repo.spring.io/milestone
[DEBUG] Using connector BasicRepositoryConnector with priority 0.0 for https://repo.maven.apache.org/maven2
[DEBUG] Using connector BasicRepositoryConnector with priority 0.0 for https://repo.spring.io/snapshot
Downloading: https://repo.spring.io/libs-milestone/com/phoenixnap/oss/springmvc-raml-plugin/maven-metadata.xml
Downloading: https://repo.spring.io/snapshot/com/phoenixnap/oss/springmvc-raml-plugin/maven-metadata.xml
Downloading: https://repo.maven.apache.org/maven2/com/phoenixnap/oss/springmvc-raml-plugin/maven-metadata.xml
Downloading: https://repo.spring.io/milestone/com/phoenixnap/oss/springmvc-raml-plugin/maven-metadata.xml
[DEBUG] Writing tracking file /home/yuranos/.m2/repository/com/phoenixnap/oss/springmvc-raml-plugin/resolver-status.properties
[DEBUG] Writing tracking file /home/yuranos/.m2/repository/com/phoenixnap/oss/springmvc-raml-plugin/resolver-status.properties
Downloaded: https://repo.maven.apache.org/maven2/com/phoenixnap/oss/springmvc-raml-plugin/maven-metadata.xml (2 KB at 1.0 KB/sec)
[DEBUG] Writing tracking file /home/yuranos/.m2/repository/com/phoenixnap/oss/springmvc-raml-plugin/resolver-status.properties
Downloaded: https://repo.spring.io/libs-milestone/com/phoenixnap/oss/springmvc-raml-plugin/maven-metadata.xml (2 KB at 0.9 KB/sec)
[DEBUG] Writing tracking file /home/yuranos/.m2/repository/com/phoenixnap/oss/springmvc-raml-plugin/resolver-status.properties
[DEBUG] Could not find metadata com.phoenixnap.oss:springmvc-raml-plugin/maven-metadata.xml in spring-snapshots (https://repo.spring.io/snapshot)
[DEBUG] Could not find metadata com.phoenixnap.oss:springmvc-raml-plugin/maven-metadata.xml in spring-milestones-libs (https://repo.spring.io/milestone)

另外，maven似乎知道如何比较几个元数据文件并选择最新版本的工件。根据我在resolver-status.properties中看到的内容，Maven利用Aether来解决依赖关系：

    #NOTE: This is an Aether internal implementation file, its format can be changed without prior notice.
#Mon Feb 19 23:41:24 EET 2018
maven-metadata-spring-milestones.xml.lastUpdated=1519076484366
maven-metadata-spring-snapshots.xml.error=
maven-metadata-central.xml.lastUpdated=1519076484205
maven-metadata-spring-snapshots.xml.lastUpdated=1519076484107
maven-metadata-spring-milestones-libs.xml.lastUpdated=1519076484105
maven-metadata-spring-milestones-libs.xml.error=

在Maven 2的命令行中设置插件的版本

4 个答案: