After downloading the "jasperreports-extensions-3.5.3.jar" file, you'll need to add it to your classpath. The exact steps will depend on your project's configuration and requirements.

javac -cp ".;jasperreports-extensions-3.5.3.jar;jasperreports-3.5.3.jar" MyReportGenerator.java java -cp ".;jasperreports-extensions-3.5.3.jar;jasperreports-3.5.3.jar" MyReportGenerator