Handling licenses of dependencies

Question

I am developing a java library, which will be released in maven central. My project depends on few others, the dependencies look something like this:

<dependencies>
     <dependency>
         <groupId>org.slf4j</groupId>
         <artifactId>slf4j-api</artifactId>
         <version>1.7.32</version>
     </dependency>
     <dependency>
         <groupId>org.junit.jupiter</groupId>
         <artifactId>junit-jupiter-api</artifactId>
         <version>5.8.2</version>
         <scope>test</scope>
     </dependency>
</dependencies>

For the last few days i am hindered by handling the licenses of these dependencies.
SLF4J for example is MIT licensed and the license states - The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. How exactly should i include the SLF4J license in the artefacts? Do i even need to include it, considering that normally artefacts don't contain their dependencies?
Similarly i am not sure how to handle test dependencies, do i need to include licenses and agreements for them, considering they are only used during the test stage of builduing asrtefacts?

Answer 1

As you noticed, the MIT license requires that its text be included in all "copies or substantial portions of the Software". So, if you distribute a copy of part or all of SLF4J, either on its own or as part of some larger program or package, you need to include the MIT license with that distribution and indicate that the license applies to the copied part. But if whatever you distribute does not include SLF4J itself, the MIT license does not impose any requirements on that distribution: you wouldn't have to include the copyright notice and license text for SLF4J in a distribution that does not actually contain SLF4J.

The same goes for any other dependency covered by the MIT license. Other licenses might have some requirements you need to fulfill even if you're not distributing the dependency itself, though. The classic example is the GPL, which requires that the dependent software (i.e. your program that depends on a GPL library) also be licensed under the GPL - at least, it probably does, depending on just how tight of a dependency it is.

See also Do I need to include the license for all dependencies declared in a setup.py? which is much the same question in the context of Python instead of Java (but the language doesn't matter).