Joseph D. Darcy's Sun Weblog

Thursday August 13, 2009

JDK 7: New Component Delivery Model in the Works

The JDK includes many logically distinct sets of APIs. Some of the APIs naturally live in the JDK and evolve at the pace of the JDK; other APIs are effectively maintained externally, but are also shipped as part of the public API provided by the JDK. Two APIs in the latter camp are jaxp and jax-ws, both of which natively live in the GlassFish project.

Currently, those components are maintained under separate version control as part of OpenJDK in the jaxp and jax-ws repositories, respectively. Code in these components is periodically synced with changes from the upstream masters, with some nontrivial overhead.

To reduce the overhead of updating the components and thereby make it possible to update them more frequently, we're in the process of changing the delivery model of these externally maintained components into the JDK. First for JDK 7 and later for OpenJDK 6, instead of tracking these code bases under independent version control in the JDK, the JDK build will logically get the source for those components from a source bundle. The upstream teams will be responsible for providing source bundles and the JDK build will be configurable to use a particular source bundle.

Kelly has been working in implementing this new model for jaxp in the JDK 7 build, including working out the detailed logistics with the upstream teams. An initial version of the change is out for review.

This new approach is the same basic model the IcedTea project uses to provide changes and functionality on top of OpenJDK so there is lots of evidence large code bases can be handled using this model.