add external JARs to java vscode code example

Example: add external JARs to java vscode

1. Add the jar to a folder you prefer, e.g. a new directory "lib" in
the project folder.
2. Add a line like: <classpathentry kind="lib" path="C:\\...\\yourlib.jar"/>
to your .classpath.
3. Done. You can simply import it as you are used to.