How to include resource file into osgi bundle from jar dependency with bnd/maven-bundle-plugin?

Question

I'm using maven-bundle-plugin (bnd effectively).

It's straightforward to include a resource file from sources.

For example, a resource file (src/main/resources/some.xml) is moved under target directory (target/classes/some.xml) during build time and can be included into the bundle using <Include-Resource> instruction:

<plugin>
    <groupId>org.apache.felix</groupId>
    <artifactId>maven-bundle-plugin</artifactId>
    <version>3.0.1</version>
    <extensions>true</extensions>
    <configuration>
        <instructions>
            <Include-Resource>
                some.xml=target/classes/some.xml,
            </Include-Resource>
        </instructions>
    </configuration>
</plugin>

Let us have a dependency:

<dependency>
    <groupId>com.example</groupId>
    <artifactId>library</artifactId>
    <version>1.0.0</version>
</dependency>

How to reference resource file inside dependent jar?

In other words, how to

• specify something like this:

  com.example:library:1.0.0:jar/some.xml
  

• instead of this:

  target/classes/some.xml
  

so that resource from one of the dependency appeared in output bundle jar?

Odyssey

I don't understand the question. Are you asking how to reference some.xml at runtime from code inside the bundle? – Telford

I just want to package bundle jar with some.xml taken from inside of another (dependency) jar. Ultimately, this will be referenced by code, but before it can be referenced by code, it should be packaged into output jar. – Odyssey

Answer 1

You can use the maven-dependency-plugin to un-compress your dependencies jar and then include the resource in your jar.

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-dependency-plugin</artifactId>
    <executions>
        <execution>
            <id>unpack-dependencies</id>
            <phase>generate-resources</phase>
            <goals>
                <goal>unpack</goal>
            </goals>
            <configuration>
                <markersDirectory>${project.build.directory}/dependencies/dependency-maven-plugin-markers</markersDirectory>
                <artifactItems>
                    <artifactItem>
                        <groupId>DEPENDENCY_GROUPID</groupId>
                        <artifactId>DEPENDENCY_ARTIFACTID</artifactId>
                        <type>OPTIONAL_DEPENCENCY_TYPE</type>
                        <outputDirectory>${project.build.directory}/dependencies/DEPENDENCY_ARTIFACTID</outputDirectory>
                    </artifactItem>
                </artifactItems>
            </configuration>
        </execution>
    </executions>
</plugin>
...
<plugin>
    <groupId>org.apache.felix</groupId>
    <artifactId>maven-bundle-plugin</artifactId>
    <configuration>
        ...
        <instructions>
            ...
            <Include-Resource>target/dependencies/DEPENDENCY_ARTIFACTID/some.xml</Bundle-Activator>
        </instructions>
    </configuration>
</plugin>

The Include-Resource instructions is supposed to be pom relative, see Include-Resource, you can probably replace targetwith ${project.build.directory}.

Maimonides

Honestly, I expected there could be a trick from maven-bundle-plugin/bnd to select resources to be moved into output bundle jar similarly as the plugin does when Private-Package instruction specified with packages (and these packages become part of the output bundle jar). However, this answer is straightforward and goes around by cutting off some responsibilities from the sophistication of maven-bundle-plugin. – Odyssey

Answer 2

If you have a file reference to the jar, you can do

-includeresource: @path/to/file.jar!/some.xml

You use the @ prefix to say the resource is in the jar and the !/ syntax from jar urls.

The tricky part will be getting a path to the jar from the project dependencies I suspect.

Telford

Indeed. I don't know how to reliably reference copy of the jar file which is listed as Maven dependency. So, the answer with maven-dependency-plugin was acceptable and fixed the problem for now. However, I might need your piece of information too - upvoting. Thanks! – Odyssey

For more info, you can get a path to a jar using the (I think undocumented) repo macro, e.g: -includeresource: @${repo;org.apache.felix.http;latest}!/META-INF/LICENSE You can even do things like this (but not in the cnf project as I guess the repos haven't been defined yet): -include: jar:${fileuri;${repo;bsn;version}}!/resource.properties – Elenoraelenore

This question is about a maven build, so their is no bnd workspace and so it is unlikely any repos are configured for the repo macro to be of any use. – Telford

Oh dear, right you are! I just came from Google with my slightly related problem without properly understanding the context. Well, hopefully it will help someone out all the same. – Elenoraelenore