因为未定义的版本,我在maven构建中得到"构建无法读取1个项目"

Question

我有一个父母pom和一个集成pom:
整合pom

<dependencies>
    <dependency>
        <groupId>org.json</groupId>
        <artifactId>json</artifactId>
    </dependency>

    <dependency>
        <groupId>commons-httpclient</groupId>
        <artifactId>commons-httpclient</artifactId>
    </dependency>

    <dependency>
        <groupId>com.example</groupId>
        <artifactId>example-model</artifactId>
    </dependency>

</dependencies>
<parent>
    <groupId>com.example</groupId>
    <artifactId>example-parent</artifactId>
    <version>0.0.1-SNAPSHOT</version>
</parent>

父母pom

<modules>
    <module>../example-business</module>
    <module>../example-integration</module>
    <module>../example-model</module>
</modules>
<dependencyManagement>
    <dependencies>

        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20131018</version>
        </dependency>

        <dependency>
            <groupId>commons-httpclient</groupId>
            <artifactId>commons-httpclient</artifactId>
            <version>3.1</version>
        </dependency>

        <dependency>
            <groupId>com.example</groupId>
            <artifactId>example-model</artifactId>
            <version>${project.version}</version>
        </dependency>

    </dependencies>
</dependencyManagement>

现在,当我在父进程上进行全新安装时,出现以下错误:

[INFO] Scanning for projects...
Downloading: http://www.example.com/content/groups/mirror/com/example/example-parent/0.0.1-SNAPSHOT/maven-metadata.xml
[ERROR] The build could not read 1 project -> [Help 1]
[ERROR]   
[ERROR]   The project com.example:example-integration:0.0.1-SNAPSHOT (D:\dev\workspaces\example-git\example\example-integration\pom.xml) has 3 errors
[ERROR]     'dependencies.dependency.version' for org.json:json:jar is missing. @ line 22, column 15
[ERROR]     'dependencies.dependency.version' for commons-httpclient:commons-httpclient:jar is missing. @ line 27, column 15
[ERROR]     'dependencies.dependency.version' for com.example:example-model:jar is missing. @ line 32, column 15

但是当我看一下集成pom的Effective POM时,就会有一个版本.
那我为什么不能建造呢？

---

编辑:
以下是EFFECTIVE POM视图的片段:

<dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.json</groupId>
        <artifactId>json</artifactId>
        <version>20131018</version>
      </dependency>
      <dependency>
        <groupId>commons-httpclient</groupId>
        <artifactId>commons-httpclient</artifactId>
        <version>3.1</version>
      </dependency>
      <dependency>
        <groupId>com.example</groupId>
        <artifactId>example-model</artifactId>
        <version>0.0.1-SNAPSHOT</version>
      </dependency>
      <dependency>
        <groupId>com.example</groupId>
        <artifactId>example-integration</artifactId>
        <version>0.0.1-SNAPSHOT</version>
      </dependency>
      <dependency>
        <groupId>com.example</groupId>
        <artifactId>example-business</artifactId>
        <version>0.0.1-SNAPSHOT</version>
      </dependency>
    </dependencies>
  </dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>org.json</groupId>
      <artifactId>json</artifactId>
      <version>20131018</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>commons-httpclient</groupId>
      <artifactId>commons-httpclient</artifactId>
      <version>3.1</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>com.example</groupId>
      <artifactId>example-model</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>com.example</groupId>
      <artifactId>example-business</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <scope>compile</scope>
    </dependency>
  </dependencies>

Answer 1

问题在于您的项目结构以及如何parent在子poms中定义它们.

您的子模块实际上位于父pom所在的文件夹中,而不是在同一级别(从中判断<module>../example-business</module>).当maven尝试构建子模块时,它找不到父pom,因为它在maven存储库中不可用(它当前正在构建它以便它尚未上传).

要解决此问题,您只需更改parent子poms中的定义,以定义relativePath父pom的位置,以便maven可以找到它.因此,将其更改为如下所示:

<parent>
    <groupId>com.example</groupId>
    <artifactId>example-parent</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <relativePath>../name-of-folder-containing-parent-pom</relativePath>
</parent>

显然你需要改变name-of-folder-containing-parent-pom成文件夹.