Maven项目需要建立本地依赖关系

Question

I have 2 Maven projects, A and B. Project A is entirely independent, while B requires A as a dependency. Currently, B is getting A from the maven repository:

<dependency>
  <groupId>com.myproject</groupId>
  <artifactId>projectA</artifactId>
  <version>2.0.0-SNAPSHOT</version>
</dependency>

What I would like to do is set up the dependency such that B can reference the local instance of A. I can do the following:

<dependency>
  <groupId>com.myproject</groupId>
  <artifactId>projectA</artifactId>
  <version>2.0.0-SNAPSHOT</version>
  <scope>system</scope>
  <systemPath>${basedir}/../projectA/target/projectA-2.0.0-SNAPSHOT.jar</systemPath>
</dependency>

but this only works if A is already built (so projectA-2.0.0-SNAPSHOT.jar already exists).

Is there a way to force A to build before B in cases where I don't already have a build of A?

Answer 1

One way is you create a parent pom, and add these projects as child modules. So, the directory structure would look like this:

+ pom.xml
|
+-A
|  \ 
|   + pom.xml
+-B 
   \
    + pom.xml

The parent pom would have <modules> tag, adding A and B projects as child modules:

<groupId>com.myproject</groupId>
<artifactId>parent</artifactId>
<version>2.0.0-SNAPSHOT</version>
<packaging>pom</packaging>

<modules>
    <module>A</module>
    <module>B</module>
<modules>

And then, add A module as dependency to B module. Just keep the group-id same for parent, A and B. And then refer the module using artifact-id.

pom.xml for B would be like:

<parent>
    <groupId>com.myproject</groupId>
    <artifactId>parent</artifactId>
    <version>2.0.0-SNAPSHOT</version>
</parent>
<artifactId>projectB</artifactId>

<dependencies>
    <dependency>
        <groupId>com.myproject</groupId>
        <artifactId>projectA</artifactId>
        <version>2.0.0-SNAPSHOT</version>
    </dependency>
</dependencies>

Now, build the parent pom. It will take care of build order.