OSGi Service Platform V4.2 new features

After nearly two years of preparation, the OSGi Alliance finally released the latest version of the OSGi Service Platform V4.2 specification in September 2009. Among them, the new Core Specification V4.2 specification adds Framework Launching,service Hooks concept, and the Conditional Permission Admin standard is improved and supplemented to facilitate Ann Fully managed and configured. In addition, with the strong impetus of the Enterprise Expert Group, the new Service Compendium V4.2 specification introduces Blueprint services, Remote services, Bundle Tracker, and other new standards to support enterprise applications, thus blowing A clarion call for OSGi Service Platform to march toward the enterprise-level market.

OSGi Service Platform Technical background

In the past two years, the development of OSGi technology has been very rapid, causing more and more manufacturers in the industry concern. In fact, however, OSGi is not a new term, and it has gone through 10 years of development by this year. Founded in 1999, the OSGi Alliance is a non-profit international organization designed to establish an open service specification and open standards for service delivery through the network, and is the initiator of open business gateways. At first, OSGi technology was focused on embedded areas, such as set-top boxes, service gateways, mobile phones and other applications, and in 2003 BMW built its Smart car AV system based on OSGi V3.0 specifications. With the development of time, many of OSGi's outstanding features, such as dynamic, modular, extensibility, are gradually recognized and appreciated by more developers, so they can be applied to the design and development of desktop programs. Eclipse started with the V3.0 M5 version, designed the Equinox kernel, and used OSGi technology to help with class loading, which greatly increased the boot speed, in fact, Equinox is an implementation of the OSGi Framework. At the same time, the impact of OSGi technology extends to the Java community, JSR-232 that OSGi technology has begun to be recognized by the Java ME family, while JSR-291 extends the tentacles of OSGi technology to the Java SE and Java EE categories. The number of members of the OSGi Alliance has grown from the first few to more than 100, and many of the world's leading IT companies have joined the camp, such as Ibm,oracle,sap,red Hat,springsource, and many of their products have been declared to support or use OSGi technology, such as Websphere,weblogic,jboss,spring DM, and so on, from one side of the description of OSGi technology in the enterprise-level market promising. Thus, the scope of OSGi is already not covered by its original literal meaning (Open Service Gateway Initiative), and today the OSGi federation gives the definition "a dynamic module system for Java", which is a dynamically J Ava Modular System.

In September this year, the OSGi Alliance released the latest version of the V4.2 standard, which was nearly two years after the release of V4.1, and in two years, the OSGi Alliance members presented a number of new requirements, so the new OSGi Core specification and Service Compendiu M specification has added a lot of new content, and it is worth mentioning that, with the effort of the Enterprise Expert Group (Enterprise Expert Group, EEG), many new features are designed for the enterprise application or application server domain, Now let's take a look at the background and solutions to these new features.

New characteristics of Core specification V4.2

Framework Launching

This is RFC 132, which defines a unified startup method and interface for OSGi Framework implementations.

Problem background:

Prior to V4.2, the OSGi Framework implemented by different vendors tended to define the starting interface, initialization parameters, and resource allocation methods according to their own custom. For example, there is no uniform way to accomplish this invocation when we want to connect to an external connection to the Eclipse Equinox,apache Felix implementation. So, if a third-party product built on the OSGi framework wants to support different OSGi framework implementations, you need to prepare multiple copies of the boot corner and configuration files.