Creating a New JOnAS Service

The content of this guide is the following:

  1. Target Audience and Rationale
  2. Introducing a new Service
  3. Advanced Understanding

Target Audience and Rationale

This chapter is intended for advanced JOnAS users who require that some "external" services run along with the JOnAS 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 JONAS Server. The JOnAS pre-defined services are listed in Configuring JOnAS services.

J2EE 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 application 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 JOnAS server.

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 file must be modified to make JOnAS aware of this service.

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:

It should also define a public constructor with no argument.

These methods will be called by JOnAS for initializing, starting, and stopping the service. Configuration parameters are provided to the initialization method through a naming context. This naming context is built from properties defined in the file as explained in the following section.

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 {
String p1 = (String) ctx.lookup("jonas.service.serv1.p1");
} catch (NamingException e) {
throw new ServiceException("....", e);
public void start() throws ServiceException {
this.started = true;
public void stop() throws ServiceException {
if (this.started) {
this.started = false;
public boolean isStarted() {
return this.started;
public String getName() {
public void setName(String name) { = name;

Modifying the file

The service is defined and its initialization parameters specified in the file. First, choose a name for the service (e.g. "serv1"), then do the following:

This is illustrated as follows:                   .......,serv1
jonas.service.serv1.class a.b.MyService
jonas.service.serv1.p1 value

Using the New Service

The new service has been given a name in With this name, it is possible to get a reference on the service implementation class by using the ServiceManager method: getService(name). The following is an example of accessing a Service:
import org.objectweb.jonas.service.ServiceException;
import org.objectweb.jonas.service.ServiceManager;

MyService sv = null;

// Get a reference on MyService.
try {
sv = (MyService) ServiceManager.getInstance().getService("serv1");
} catch (ServiceException e) {
Trace.errln("Cannot find MyService:"+e);

Adding the class of the new service to JOnAS

Package the class of the service into a .jar file and add the jar in the JONAS_ROOT/lib/ext directory.
All the libraries required by the service can also be placed in this directory.

Advanced Understanding

Refer to the JOnAS sources for more details about the classes mentioned in this section.

JOnAS built-in services

The existing JOnAS services are the following:

Service name Service class
registry RegistryServiceImpl
ejb EJBServiceImpl
web CatalinaJWebContainerServiceImpl / JettyJWebContainerServiceImpl
ear EarServiceImpl
dbm DataBaseServiceImpl
jms JmsServiceImpl
jmx JmxServiceImpl
jtm TransactionServiceImpl
mail MailServiceImpl
resource ResourceServiceImpl
security JonasSecurityServiceImpl

If all of these services are required, they will be launched in the following order: registry, jmx, security, jtm,dbm,mail,jms,resource,ejb, ws, web, ear.
jmx, security, dbm, mail, resource are optional when you are using service ejb.

registry must be launched first.
(Note that for reasons of compatability with previous versions of JOnAS, if registry is unintentionally not set as the first service to launch, JOnAS will automatically launch the registry service.)

Note that dbm, jms, resource, and ejb depend on jtm.
Note that ear depends on ejb and web (that provide the ejb and web containers), thus these services must be launched before the ear service.
Note that ear and web depends on ws, thus the ws service must be launched before the ear and web service.

It is possible to launch a stand-alone Transaction Manager with only the registry and jtm services.

A file looks like the following:

..... registry,jmx,security,jtm,dbm,mail,jms,ejb,resource,serv1

jonas.service.registry.class org.objectweb.jonas.registry.RegistryServiceImpl
jonas.service.registry.mode automatic

jonas.service.dbm.class org.objectweb.jonas.dbm.DataBaseServiceImpl
jonas.service.dbm.datasources Oracle1

jonas.service.ejb.class org.objectweb.jonas.container.EJBServiceImpl
jonas.service.ejb.descriptors ejb-jar.jar
jonas.service.ejb.parsingwithvalidation true
jonas.service.ejb.mdbthreadpoolsize 10

jonas.service.web.class org.objectweb.jonas.web.catalina.CatalinaJWebContainerServiceImpl
jonas.service.web.descriptors war.war
jonas.service.web.parsingwithvalidation true

jonas.service.ear.class org.objectweb.jonas.ear.EarServiceImpl
jonas.service.ear.descriptors j2ee-application.ear
jonas.service.ear.parsingwithvalidation true

jonas.service.jms.class org.objectweb.jonas.jms.JmsServiceImpl org.objectweb.jonas_jms.JmsAdminForJoram
jonas.service.jms.collocated true
jonas.service.jms.url joram://localhost:16010

jonas.service.jmx.class org.objectweb.jonas.jmx.JmxServiceImpl

jonas.service.jtm.class org.objectweb.jonas.jtm.TransactionServiceImpl
jonas.service.jtm.remote false
jonas.service.jtm.timeout 60

jonas.service.mail.class org.objectweb.jonas.mail.MailServiceImpl
jonas.service.mail.factories MailSession1

jonas.service.resource.class org.objectweb.jonas.resource.ResourceServiceImpl
jonas.service.resource.resources MyRA

jonas.service.serv1.class a.b.MyService
jonas.service.serv1.p1 John

The ServiceException

The org.objectweb.jonas.service.ServiceException exception is defined for Services. Its type is java.lang.RuntimeException. and it can encapsulate any java.lang.Throwable.

The ServiceManager

The org.objectweb.jonas.service.ServiceManager class is responsible for creating, initializing, and launching the services. It can also return a service from its name and list all the services.