Sun is working on a long list of potential features for the planned JDK (Java Development Kit) 7, which is based partially on the upcoming Java Standard Edition (SE) 7.

JDK7 is expected to have a consumer focus, although an XML accommodation originally envisioned may not make it into the final product.

"There is still a client and consumer focus, so certainly some of the features for the JavaFX release might find their way into JDK7," said Chet Haase, a client architect in the Java SE group at Sun, at the QCon conference in San Francisco on Wednesday afternoon.

JavaFX is Sun's planned implementation of Java technology providing for multimedia applications on a range of systems. JavaFX features, such as media support, animation, and a component offering broader HTML backing, could end up in JDK7. Developers could render arbitrary HTML, according to Haase.

But a capability to accommodate XML strings in Java code may not make the final cut. "That's not as high-priority," as some of the other features, said Haase.

JDK7 is expected to ship until no earlier than late 2008 and probably later than that.

Improvement in the HotSpot Java Virtual Machine is planned for JDK7. "There's always work in every release going on there to make things faster," Haase said.

Among other features on the drawing board is closures, for passing around arbitrary code blocks. "Closures is a huge project," Haase said. A strings-in-switch-statements capability, meanwhile, allows a switch statement to go to different points in code based on the value of the string. Also, a capability to invoke dynamic byte code may be added to bolster scripting.

Capabilities from several JSRs (Java Specification Requests) are eyed for JDK7, including JSR 203, providing various I/O APIs; 277, for Java Module System; 294, for improved modular support in Java; 295, offering data binding for JavaBean objects; and 296, the Swing application framework.

Other JSRs whose work could show up in JDK7 include 255, featuring JMX (Java Management Extensions), and 262, also based on JMX and including a Web services connector.

Another feature, identified as declaring and constructing a variable instance, features syntax for shortening the declaration of variables. A planned GetJava executable capability would makes it easier to detect the current version of Java and launch the Java application to be used.

Heavyweight/lightweight mixing provides the ability to support Swing components and such components as AWT (Abstract Windows Toolkit) or Java 3D.

Haase also said that a beta release of Java SE 6 Update N, which had been planned for December, now is not due until February. The update itself is due in July 2008.