Addition, to make it clearer, I tried to print the stack trace.. and this is the result:
java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver at java.net.URLClassLoader$1.run(URLClassLoader.java:200) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:297) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:286) at java.lang.ClassLoader.loadClass(ClassLoader.java:253) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:313) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:120) at Test.main(Test.java:14) Press any key to continue . . .