Maven not copying some JAR to WEB-INF/lib

Question

I have created a Web Project using Maven in Eclipse. I need pentaho library jar for the project and this is my dependency

<dependency>
    <groupId>pentaho-library</groupId>
    <artifactId>libbase</artifactId>
    <version>1.2.8</version>
    <optional>true</optional>
</dependency>

When I run mvn:compile or mvn eclipse:eclipse, it is downloading the JAR file in maven_repo local directory I am using the following war plugin

        <plugin>
            <artifactId>maven-war-plugin</artifactId>
            <version>2.3</version>

        </plugin>

The problem is, when i run mvn war:war to create the war file, it is not copying the libbase-1.2.8.jar to the WEB-INF/lib folder. But it is copying all other JAR files. What is the problem?

Answer 1

Try removing <optional>true</optional>.

Answer 2

The Introduction to the Dependency Mechanism: Transitive Dependencies told us about the optional as the following:-

Optional dependencies - If project Y depends on project Z, the owner of project Y can mark project Z as an optional dependency, using the "optional" element.

When project X depends on project Y, X will depend only on Y and not on Y's optional dependency Z. The owner of project X may then explicitly add a dependency on Z, at her option. (It may be helpful to think of optional dependencies as "excluded by default.")

Then the optional dependency will not be included to our WEB-INF/lib.

I hope this may help.