ServiceInterceptor¶

ServiceInterceptor can be used to hook into the service lifecycle events:

• serviceCreated: Called when an IService instance is created. Please be aware that the service may not actually be used; it is very common to create an IService just to get a hold of a good ID for a service - and then throw it away.
• serviceAdded: called when a service is actually being added to the catalog; giving you a chance to configure; inject security credentials; or otherwise set a service up. The service may not yet “be connected” but it is at least now being tracked and the catalog will take responsibility for cleaning it up now.
• serviceRemoved: the time has come; the catalog is cleaning up this service.

Note that the catalog does maintains persisted properties; you can interact with these properties uding serviceAdded / serviceRemoved to provide such things as a better default title.

ShpPropertiesInterceptor.java code example of grabbing a good title from a shapefile sidecar “properties” file:

public class ShpPropertiesInterceptor implements ServiceInterceptor {
    public void run(IService service){
        if( service instanceof ShpServiceImpl){
            ID id = service.getID();
            File directory = id.toFile().getParentFile();
            File infoFile = new File( directory, id.toBaseFile()+".properties" );
            if( infoFile.exists() ){
               try {
                   FileReader infoReader = new FileReader( infoFile );
                 Properties info = new Properties();
                 info.load( infoReader );
                 String title = (String) info.get("title");
                 if( title != null ){
                   service.getPersistentProperties().put("title", title);
                 }
               } catch (IOException eek ){
               }
            }
        }
     }
}

GeoResourceInterceptor¶

In a similar manner you can have a go at setting up a IGeoResource:

• resourceAdded: called to perform any configuration or code injection (such as listeners) on a service prior to use
• resoruceRemoved: called to clean up any listeners or configuration

This is usually used to “seed” the GeoResourceInfo with a good bounds in cases where the actual underlying data is wrong.