I created the java class and converted into jar files. So, I want to use those jar files which I have placed in project level in some folder like "External Jar". So I need to write a dependency in maven that when someone imports my project they should be able to run the program.
Basically you created your own jar and you want to publish this jar, so that when somebody else clone/use your project, this jar comes with (assuming that you have a maven project and dependency of your jar is included in pom.xml).
To achieve this, you need to publish your jar to maven , you can follow many of the online docs like http://kirang89.github.io/blog/2013/01/20/uploading-your-jar-to-maven-central/ on how to publish jar to maven central.
Edit:- As suggested by khmarbaise, please use official reference http://central.sonatype.org/ for central repository.