DAO – it’s not about Layering, it’s about Abstraction!

Again there were some interesting debates in the near past, which once again discussed the role of the DAO within enterprise applications, especially based on JEE and EJB 3. One main argument for the dissapearance of DAOs is the very unlikely probability to exchange or replace your once chosen persistence technology, so that you may directly rely on EJBs Entity Manager within your Business Services (since it’s in fact very unlikely that your underlying persistence technology will change). This argument is mostly accompanied with the concern, that the introduction of a DAO Layer might increase complexity and introduce some performance penalties, while direct usage of the Entity Manager let collapse two separate Layers into one.

WS-Security using Cert Authentication with Spring-WS IV: How to set up your Clients’ Keystore

So far, our WebService is readily configured for only accepting signed messages, forcing clients to include their Certificate for decrypting the digital Signature again on server side (verifying that the message is originally send from an authorized client). In addition to that, the client’s Certificate has to be signed (issued) itself by a Certificate Authority (CA) which is accepted by the WebService (in that the CAs Certificate is contained within the WebServices Truststore)