You can include Jar files to which you need to set the classpath in the eclipse project using build path
Step 1 − Right click on the project Select Build Path → Configure Build Path.
Step 2 − Select libraries select Add External JARs… button.
Step3 − Then browse through the folder where the required jar files exits, select them and press open.
Selected jar files will be added to the Libraries. Finally, press OK.
Now, if you open the Referenced libraries in the project you can observe the added jar file.