If all you want is to make HTTPS WebService calls - this should be no different from making any other https call (webservice or not).
Make sure that the app server is configured to accept HTTPS calls.
From the calling application invoke WebService with HTTPS protocol - how to do this really depends on what kind of client code you have.
Thanks for the reply and link. So far I have modified Tomcat server.xml to uncomment the https connector, and I have created the SSL certificate using:
keytool -genkey -alias tomcat -keyalg RSA.
I changed the client code to access the web service by changing the port and http to https.
On the client machine I also ran: keytool -genkey -alias tomcat -keyalg RSA
Do I need to export the certificate from the client and send the file to the web server? I want to use the certificate to authenticate the client. If I only want to authenticate the client and not the server, does the server still have to run the keytool to create a certificate? Also, I'm not sure how to set the properties on the client side.
I would greatly appreciate any help getting answers to these questions.