Web service Java EE

I'am asking if there is a tutorial about implementing a web service with开发者_开发技巧 Java EE (SGBD --> JDBC --> JPA --> DAO --> web service) the under Tomcat Apache server.

I don't think this is correct:

Java EE (SGBD --> JDBC --> JPA --> DAO --> web service)

I don't know what SGBD is. Can you clarify?

I think it's either JDBC or JPA as the DAO implementation, but not both. Yes, I realize that all relational database access is via JDBC in Java, but JPA implies an ORM or JDO solution to me, not straight JDBC.

Here's the Spring web service tutorial and Spring MVC step-by-step.