Maven managed dependencies - resolving ${project.v

问题:

How is placeholder ${project.version} resolved for managed properties from parent pom? I've expected that it is resolved globally, so when the parent pom has version 2, ${project.version} would also be resolved to version 2.

In parent pom I have:

<groupId>my.group</groupId>
<artifactId>parent</artifactId>
<version>2</version>
<packaging>pom</packaging>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>my.group</groupId>
            <artifactId>dep</artifactId>
            <version>${project.version}</version>
        </dependency>
    </dependencies>
</dependencyManagement>     

In child I use

<parent>
    <groupId>my.group</groupId>
    <artifactId>parent</artifactId>
    <version>2</version>
</parent>
<version>1</version>
<artifactId>child</artifactId>

But the artifact my.group.dep.1.jar is used, instead of my.group.dep.2.jar. So the placeholder is resolved to the version of the project using the managed dependency, and not those of the project defining the dependency.

Is that expected behaviour? I'm using maven 3.0.4.

回答1:

You have to skip <version> tag in child, but keep the <parent><version> ... </parent> tag.

http://maven.apache.org/guides/introduction/introduction-to-the-pom.html#Project_Inheritance

One factor to note is that these variables are processed after inheritance as outlined above. This means that if a parent project uses a variable, then its definition in the child, not the parent, will be the one eventually used.