Maven多模块项目找不到兄弟模块

Question

我似乎无法让Maven在多模块项目中找到兄弟姐妹的模块。

我已经在所有模块中运行了MVN clean install。

Product
+-- MagniCompCommon
+-- Model

[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building Model 1.0
[INFO] ------------------------------------------------------------------------
[WARNING] The POM for com.magnicomp:MagniCompCommon:jar:1.0 is missing, no dependency information available
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.585 s
[INFO] Finished at: 2015-10-14T10:09:04-07:00
[INFO] Final Memory: 5M/15M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project Model: Could not resolve dependencies for project com.magnicomp:Model:jar:1.0: Failure to find com.magnicomp:MagniCompCommon:jar:1.0 in http://download.java.net/maven/2/ was cached in the local repository, resolution will not be reattempted until the update interval of Java.Net has elapsed or updates are forced -> [Help 1]

<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.magnicomp</groupId>
  <artifactId>Product</artifactId>
  <version>1.0</version>
  <packaging>pom</packaging>


  <modules>
    <module>MagniCompCommon</module>
    <module>Model</module>
    <module>Common</module>
    <module>Agent</module>
    <module>Doc</module>
  </modules>

... snip ...

    <repositories>
        <repository>
            <id>Java.Net</id>
            <url>http://download.java.net/maven/2/</url>
        </repository>

下面是MagnicCompCommonpom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>com.magnicomp</groupId>
        <artifactId>Product</artifactId>
        <version>1.0</version>
    </parent>

    <!-- <groupId>com.magnicomp.common</groupId> -->
    <artifactId>MagniCompCommon</artifactId>
    <packaging>jar</packaging>

下面是Modelpom.xml

<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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>com.magnicomp</groupId>
        <artifactId>Product</artifactId>
        <version>1.0</version>
    </parent>

    <artifactId>Model</artifactId>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>com.magnicomp</groupId>
            <artifactId>MagniCompCommon</artifactId>
            <version>1.0</version>
        </dependency>

    </dependencies>

</project>

Answer 1

在构建多模块Maven项目时，需要从根POM运行Maven命令。这意味着您需要在产品的pom.xml上运行MVN clean install。

您得到的错误是意料之中的：您只是在构建模型。在model的POM中，Maven看到了对magnicompcommon的依赖关系，因此它会尝试寻找这种依赖关系。首先，它在本地repo中搜索：由于您以前没有安装magnicompcommon，所以无法在那里找到它。因此，它会在预定义的远程存储库中查找它（也没有找到）。

您可以先在MagnicompCommon的POM上运行MVN clean install，然后在modelPOM上运行MVN clean install，但是直接在根POM上调用Maven要容易得多。它将以正确的顺序正确构建每个模块（因为model依赖于magnicompcommon，所以它将首先构建magnicompcommon，然后构建model)。

另请注意，可以删除 jar 行，因为这是默认值。