Red Hat Application Server, Manual

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Chapter 24.
JOnAS Services
This chapter is intended for advanced JOnAS users who require that some “external” services run
along with the EJB server. A service is something that may be initialized, started, and stopped. JOnAS
itself already defines a set of services, some of which are cornerstones of the EJB Server. The JOnAS
pre-defined services are listed in Section 3.5 Configuring JOnAS Services .
EJB application developers may need to access other services, for example another Web container or
a Versant container, for their components. Thus, it is important that such services be able to run along
with the EJB server. To achieve this, it is possible to define them as JOnAS services.
This chapter describes how to define a new JOnAS service and how to specify which service should
be started with the EJB server.
24.1. Introducing a New Service
The customary way to define a new JOnAS service is to encapsulate it in a class whose interface is
known by JOnAS. More precisely, such a class provides a way to initialize, start, and stop the service.
Then, the jonas.properties file must be modified to make JOnAS aware of this service.
24.1.1. Defining the Service Class
A JOnAS service is represented by a class that implements the interface
org.objectweb.jonas.service.Service
, and, thus should implement the following methods:
• public void init(Context ctx) throws ServiceException;
• public void start() throws ServiceException;
• public void stop() throws ServiceException;
• public boolean isStarted();
• public String getName();
• public void setName(String name);
It should also define a public constructor with no argument.
These methods will be called by JOnAS for initializing, starting, and stopping the service. Config-
uration parameters are provided to the initialization method through a naming context. This naming
context is built from properties defined in the
jonas.properties
file as explained in Section 24.1.2
Modifying the jonas.properties File .
The Service class should look like the following:
package a.b;
import javax.naming.Context;
import javax.naming.NamingException;
import org.objectweb.jonas.service.Service;
import org.objectweb.jonas.service.ServiceException;
.....
public class MyService implements Service {
private String name = null;
private boolean started = false;
.....
public void init(Context ctx) throws ServiceException {
try {