In Java, what is the difference between a top-down web service and a bottom-up web service? Also, what is the difference between a SOAP and a REST-ful web service?
Top-down means you start with a WSDL and then create all the necessary scaffolding in Java all the way down.
Bottom-up means you start with a Java method, and generate the WSDL from it.
SOAP means that the URL is the same for all invocations, and only the parameters to the Java method differs. REST means that the URL plus the HTTP method invoked on it reflects the operation to be done.