2

This should be pretty simple, but I can't the around to it. I need to create an uberjar using 3rd party jars. I've already followed these instructions: Including a non-Mavenized dependency so it works with maven-shade-plugin and added them to the local repository. But now what? Every Maven tutorial/example is kinda shady (pun intended) and I just don't know how to edit the .pom file properly in order to make it work.

Besides, I'm confused about the shade "plugin" overall. I mean, I followed the basic Maven tutorials and it went all fine and dandy. But when I look into the shade plugin page, I can't find it to download, except for the source code. I mean, isn't it a plugin? Shouldn't I download the binaries and install it into Maven somehow?

Sorry about the extreme noobish question but, needless to say, I know squat about Maven.

Community
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makoshichi
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2 Answers2

5

To create your shaded (uber) jar, you just need to declare the shade plugin in your pom.xml.

With regards to installation of the shade plugin, simply declaring it in the plugins section of your pom.xml is all you need do. Maven plugins are not installed manually, but are automatically downloaded by Maven (if not already downloaded; just like dependencies), stored in your local repository, and used whenever a project needs them.

As to using it, much like other plugins, declare it in your pom.xml by adding a <plugin> element with your configuration needs. This plugin does nothing automatically (some do, some don't) - you have to specify which "goal" to execute (think "method of a class"), and in which "phase" (think "step" of the build process). Unless you have strange needs, specify the "shade" goal in the "package" phase (see below).

For more configuration possibilities, see the shade usage page, and their examples (especially selecting contents for uber jar). Here is a simple example which, when you run mvn package, replaces your original jar in the target/ directory with the uber jar. It only includes the runtime dependencies, not the ones used at test time (notice the <scope> element of the junit dependency, which is not included in the uber jar).

<project>
  <groupId>com.sample</groupId>
  <artifactId>test</artifactId>
  <version>1.0</version>
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>1.5</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  <dependencies>
    <dependency>
      <groupId>com.sample</groupId>
      <artifactId>test-core</artifactId>
      <version>1.0</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>
Chadwick
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0

If you have already downloaded the binaries and installed them into your local Maven repository all that remains is to declare them as dependencies in the POM. If the shade plugin is also declared in the POM a simple "mvn install" should generate a standalone JAR in the target directory.

kwo
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