Generally, we get this issue In JDBC  connection code. On compile time it will not show any issue but when we run code will receive it because of Oracle Jar not added in  CLASSPATH  while JDBC is trying to load Oracle Driver by reflection.

Exception :

java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at JDBCConnection.openConnection(JDBCConnection.java:19)
at JDBCConnection.main(JDBCConnection.java:9)

Solution :

Add Oracle jar in your classpath.

Issues Solution

For more JDBC issue solution follow link Common JDBC Issues.