Need Apache commons-lang3 as dependency of an Eclipse plugin built with Tycho

Question

I'm having one of those nights... I'm developing an Eclipse plugin using Tycho (the Maven extension), and at some point I wanted simply to use the class StringUtils from org.apache.commons. After some research, the only way that I could find is the following code in my pom.xml parent file:

  <dependencies>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.3.2</version>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.eclipse.tycho</groupId>
        <artifactId>tycho-maven-plugin</artifactId>
        <version>${tycho.version}</version>
        <extensions>true</extensions>
      </plugin>

      <plugin>
        <groupId>org.eclipse.tycho</groupId>
        <artifactId>target-platform-configuration</artifactId>
        <version>${tycho.version}</version>
        <configuration>
            <pomDependencies>consider</pomDependencies>
          <environments>
            <environment>
              ...

This didn't work, and any other solution that I tried didn't work either. I'm using Maven for the first time, so maybe I'm missing something (or a lot of things)... Does anyone have an idea? I'd be very thankful :o)

Answer 1

Your configuration looks correct. So if it doesn't work, you are probably missing the dependency declaration in the MANIFEST.MF. To do this, e.g. add Require-Bundle: org.apache.commons.lang3 in that file.

Background: A dependency in the POM doesn't automatically mean for Tycho that your bundle also automatically has this dependency. It only means that the artifact will be added to the target platform (given that pomDependencies=consider is configured and the artifact is an OSGi bundle - both is true in your case). Once it is in the target platform, it can be used to resolve the dependencies declared in your bundle's MANIFEST.MF.