Simple Override Example

Example Use Case

We start out with a simple JSR175 annotation type called DeploymentInfo.

Generate Phase

The first thing we have to do is generate an AnnoBean that will act as a proxy to instances of DeploymentInfo. To do this, we simply run Annogen's compilation task on DeploymentInfo:

This generates a DeploymentInfoAnnoBean that implements DeploymentInfo:

Override Phase

Notice that the generated DeploymentInfoAnnoBean has a setter. We're now going to create an AnnoOverrider} which uses that setter to effectively change the size of the cache on {{TinyCacheEJB. We first create an instance of StoredAnnoOverrider, which is a helper class Annogen provides for building simple AnnoOverriders.

StoredAnnoOverrider requires us to make an ElementId} for the {{TinyCacheEJB class:

The StoredAnnoOverrider will provide this DeplyomentInfoAnnoBean as a replacement for the DeploymentInfo annotation on TinyCacheEJB. So, if we change the value of cacheSize on it:

We have changed the value of cache size for TinyCacheEJB as it will appear when our framework code views its DeploymentInfo annotation.

View Phase

Compared to the Override phase, the View phase is very simple. All we have to do is create an AnnoViewer using the AnnoOverrider which we created above:

This annoViewer can now tell us about any annotations want to know about. If get the DeploymentInfo for TinyCacheEJB:

we will get back a DeploymentInfo annotation object which reflects our cacheSize override. In reality, deploymentInfo is an instance of DeploymentInfoAnnoBean, but the nice thing here is that it is an isntance of our regular 175 annotation type, DeploymentInfo.