Access logging & display error pages

Access logging

Being able to properly log the activity of a Web application is a common requirement. Restlet Components know by default how to generate Apache-like logs or even custom ones. By taking advantage of the logging facility built in the JDK, the logger can be configured like any standard JDK log to filter messages, reformat them or specify where to send them. Rotation of logs is also supported; see the java.util.logging package for details.

Note that you can customize the logger name given to the java.util.logging framework by modifying the Component’s “logService” property. In order to fully configure the logging, you need to declare a configuration file by setting a system property like:

System.setProperty("java.util.logging.config.file",
        "/your/path/logging.config");

For details on the configuration file format, please check the JDK’s LogManager class.

You can also have a look at the Restlet 2.4 logging documentation.

Displaying error pages

Another common requirement is the ability to customize the status pages returned when something didn’t go as expected during the call handling. Maybe a resource was not found or an acceptable representation isn’t available? In this case, or when any unhandled exception is be intercepted, the Application or the Component will automatically provide a default status page for you. This service is associated to the org.restlet.util.StatusService class, which is accessible as an Application and Component property called “statusService”.

In order to customize the default messages, you will simply need to create a subclass of StatusService and override the getRepresentation(Status, Request, Response) method. Then just set an instance of your custom service to the appropriate “statusService” property.