This example demonstrates how to create a simple Jersey application with resource reloading capability using Grizzly HTTP Server container.
The mapping of the URI path space is presented in the following table:
| URI path | Resource class | Content | HTTP methods |
|---|---|---|---|
| /flights/arrivals | org.glassfish.jersey.examples.reload.ArrivalsResource | Dummy Arrivals Information | GET |
| /flights/departures | org.glassfish.jersey.examples.reload.DeparturesResource | Dummy Departures Information | GET |
| /flights/stats | org.glassfish.jersey.examples.reload.StatsResource | Statistics on application resource utilization | GET |
The application gets configured via a plain text file named resources.
The file contains a list of resource classes to be published by the
application. After the application gets started, it watches the file system
and reloads the application as file updates are being detected.
Changes in JAX-RS resource source files and updates of the above mentioned resources file
are being detected. Java code re-compilation is done as required.
Run the example as follows:
mvn clean compile exec:java
This deploys current example usingGrizzly container. StatsResource should be available at http://localhost:8080/flights/stats
You may want to check the other resources as well:
Updated information on number of hits should be available at
http://localhost:8080/flights/stats.
Now you can try to edit the resources file and comment the stats
resource out by using the # prefix. The point is you leave the
application running while editing the file. The changes wil get picked
up automatically. No need to manually restart the application. The
resource file content should now look like follows:
org.glassfish.jersey.examples.reload.DeparturesResource
org.glassfish.jersey.examples.reload.ArrivalsResource
#org.glassfish.jersey.examples.reload.StatsResource
Once you save the change, the stats resource should not be available, but the other, departures/arrivals, resources should remain functional.
Now you can revert the change back and check the stats resource is back providing actual statistics information.
You can also try to change the JAX-RS resources source code. These changes will be also picked up automatically.