I do get the illegal reflective access warning. My reports run correctly so far.
Have used the net.sf.jasperreports artifactId: jasperreports version: 6.15.0 with JDK 14.
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by net.sf.jasperreports.engine.util.ClassUtils (file:/C:/Users/Costis/.m2/repository/net/sf/jasperreports/jasperreports/6.15.0/jasperreports-6.15.0.jar) to constructor com.sun.org.apache.xerces.internal.util.XMLGrammarPoolImpl()
WARNING: Please consider reporting this to the maintainers of net.sf.jasperreports.engine.util.ClassUtils
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
Is there a new jasperreports-6.15.0.jar that solves the problem?