Which technology to use when implementing a REST service with Java

There is no simple answer. The first question is whether the team that want to build the REST service has already hands-on experience with some of the relevant technologies:

• JBoss 7 that uses RestEasy internally
• SpringMVC (which is - as a minus - not JAX-RS compliant)
• Spring with Apache CXF is a good choice if the team has already experience with Spring and wants to deploy on Tomcat
• It is even easier to run Jersey (the JAX-RS reference implementation) in Tomcat if there is no Spring support needed
• Restlet would be another option that I haven't used until now. Here is a comparison between Restlet and Jersey. 

Another reason for decision are the specific features that should be supported by the REST service (security, performance, specific headers, ...). The frameworks given above should be analyzed according to those features.

nodejs can be an alternative to Java, especially Express or Restify. no backend (e.g. with deployd or hood.ie) could be interesting for prototyping.