Java Database Connectivity (JDBC)

public ReadDB() throws SQLException{
String USERNAME = "system";//change to your Oracle username
String PASSWORD = "seconds";// change to your Oracle password
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:XE",
USERNAME, PASSWORD);

The Class.forName above is not connecting to Oracle. Have I got the wrong class name.
The JDeveloper is connecting using the JDBC though.

The following error occured;

java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:164)
at ReadDB.<init>(ReadDB.java:14)
at ReadDB.main(ReadDB.java:96)