Choosing a stack - Enterprise OSGi in Action

Java Reference

In-Depth Information

products. You can go for a minimal runtime, like Apache Karaf, or an enterprise-

strength server like WebSphere Application Server, or anything in between. How you

choose will depend on how much server you want and also how much enterprise OSG i

you want, because some products provide more of the programming model than others.

Let's start with a high-level view of which servers have the enterprise OSG i features

we've discussed in this topic.

13.1

What's in what server?

The OSG i function in these servers has different levels of maturity. Some haven't com-

pleted implementing the enterprise OSG i specification yet, whereas others provide

the specification and innovations on top of it. Implementations that aren't complete

at the time of writing will continue to improve over time and may be fully mature by

the time you're choosing your stack. It may also be that your application doesn't

require the whole enterprise OSG i programming model, in which case you can choose

your server based on other criteria. All of the servers we'll look at allow you to run

OSG i bundles as web applications, and connect bundles together using some form of

dependency injection of OSG i services.

Table 13.1 summarizes the features available in the various servers. You should

only take this table as a rough guide; some servers might not have had a feature at the

time of writing, but it might have been added by the time you're using the server.

Other features might be available in principle, but require configuration to get work-

ing in your application!

Table 13.1

Feature comparison of enterprise OSGi servers

Apache

Geronimo

Paremus

Nimble

Server

Apache Karaf

IBM WebSphere

Eclipse Virgo

GlassFish

JBoss

Blueprint

✔

*

Declarative

Services

✔

*

JPA

J

✔

On

roadmap

*

JTA

✔

*

JNDI

✔

*

Aggregate

applications

Features, .eba