ClassNotFoundException: org.apache.derby.jdbc.EmbeddedDriver when trying to use JPA with Derby
问题 A related query I asked: How to configure & package a simple Java app to use JPA I have a simple Derby database which I can connect to via EJBs hosted in WebLogic. Now I would like to connect to it from a command line Java app using JPA. So far this Java code + persistence.xml file is throwing the error below. What am I doing wrong? My directory layout: C:. │ Registrar.class │ Registrar.java │ TxnClient.class │ TxnClient.java │ └───META-INF persistence.xml Standalone client: import javax