Modularity is an important aspect of large Java systems. Build scripts and projects are often split up into modules in order to improve the build, but this is rarely taken into account at runtime. This third part of the Modular Java series discusses dynamic modularity, how a bundle's classes are resolved, how they can come and go, and how they can communicate with each other.
Last week saw the first OSGi DevCon London, held in conjunction with JAX London in Hammersmith's Novotel. Topics included features from the upcoming OSGi Enterprise Expert Group publication, using and testing OSGi in the cloud, accessing objects through JPA on an OSGi system and how modularity can defeat complexity brought on by exponential software growth.
The OSGi Alliance has just released the OSGi 4.2 specification. Although early drafts of it have previously been available, this is the final release version. What does this release hold? InfoQ has previously covered a sneak preview, but now that the spec is final, here are the new and noteworthy items of OSGi 4.2.
Long plagued by controversy, Sun's attempts to modularise the Java platform saw more positive reactions from the JavaOne crowd.
Modularity is an important aspect of large Java systems. Build scripts and projects are often split up into modules in order to improve the build, but this is rarely taken into account at runtime. This second part of the Modular Java series discusses static modularity, the creation of bundles, how to install them into an OSGi engine and how to set up (versioned) dependencies between bundles.
Over the last few years, modularity for Java has been an active discussion topic. From the (now defunct) JSR 277 to the recognition of JSR 291 and the ongoing JSR 294, modularity is seen as a necessary step in Java's evolution. Even future JVM-based languages like Scala are considering modularity. So, what does modularity mean, and why should you care?
This presentation attacks the problem of software complexity and how various modularity paradigms (e.g., object, functions, aspects) simplify complexity and help separate concerns. This talk explores the design problems where these paradigms are most applicable and extract rules of thumb for when to use them. We will also look at language support for these paradigms.
Neil Bartlett presents OSGi to Java developers: an introduction to OSGi – the standard module system for Java -, infrastructure projects using OSGi, the partial failure of OOP, the benefits of using COP – Component Oriented Programming – and how to implement components, including a demo.
This interview, conducted at QCon 2009, covers a wide range of topics beginning with a definition of OSGi and ending with an audience question about integrating OSGi into legacy application servers (like Websphere). In between Neil answers questions about the origins and evolution of OSGi, how OSGi compares to .Net modularization, and constraints on the use of certain Java libraries.
