Just make sure....Do you have any of the below jar file in your classpath.
What
IDE you are using? try to set axis jars classpath on command prompt and run WSDL2Java command from there.
Information on class org.apache.axis.wsdl.WSDL2Java:
Containing JAR files:
axis.jar
axis-1.0.jar
axis-1.1.jar
axis-1.2.1.jar
axis-1.2.jar
axis-1.3.jar
axis-1.4.jar
axis-1.4.jar
axis-1.1-beta.jar
axis-1.2-RC1.jar
axis-1.2-RC2.jar
axis-1.2-RC3.jar
axis-1.2-alpha-1.jar
axis-1.2-beta-2.jar
axis-1.2-beta-3.jar