If you can't find the jar in any Maven repository, you could apply any of the following actions, depending on your needs:
Internal Maven Repository
If you don't have an internal repository (like Artifactory or Nexus), normally used in companies as internal maven cache/proxy/point-of-control, but could also be an option to install it and run it locally.
You could then upload the library there, providing Maven GAV (GroupId, ArtifactId, Version) and make Maven pointing to it as a repository (for your, for your CI server if any, for your colleagues if any). You can then add the library as standard maven dependency.
This solution has longer set-up, but better maintainability.
Install the library in local cache
You could use the Maven Install Plugin and install the library to your local cache, as shown by this official example.
Basically, you could run the following command:
mvn org.apache.maven.plugins:maven-install-plugin:2.5.2:install-file -Dfile=path-to\wlclient.jar -DgroupId=weblogic -DartifactId=wlclient -Dversion=1.0.0 -Dpackaging=jar
It will copy the library to your local Maven cache with standard Maven GAV. However, as above, you should make sure to replicate the same set up on any CI server and any team mate machine as well. You can then add the library as standard maven dependency.
This solution has quicker set-up, but lower maintainability though.
Both solutions however affect the portability of your build (build would fail if someone tries to build it outside of your company network or team).
Use dependency with system scope
You can have the jar as part of your project and point at it via the system
scope for that dependency.
<dependency>
<groupId>weblogic</groupId>
<artifactId>wlclient</artifactId>
<version>1.0.0</version>
<systemPath>${basedir}/path/to/library/wlclient-1.0.0.jar</systemPath>
<scope>system</scope>
</dependency>
You should rename the jar though in order to be compliant with Maven conventions.
This solution is more portable, requires much less set-up, but again it needs to be maintained and requires a check-in of the concerned library as part of your versioned project (some may strongly disagree on this practice).