Java EE 6 The final draft hints at the future direction of the platform

Java EE 6 The final draft hints at the future direction of the platform

Author Charles Humble translator Zhang Long posted on October 19, 2009 1:4 P.M.

JSR-316 (Java EE 6) The expert group recently released the final draft of the specification. As opposed to earlier drafts, the final draft has 3 important changes, namely, increased JSR-330 (dependency injection for Java), JSR-299 (context and dependency injection for the Java EE platform, hereafter known as "CDI"), and JSR-303 (Bean Validation), these three specifications will become a complete platform and the necessary components of the web. To match CDI and JSR-330, the group also presented another final draft, which reuses the dependency injection annotations defined in JSR-330, while adding structural injection and other minor changes to the EJB session bean.

In addition to the previously published Web profile and complete specification documentation, the Expert Group added a specification document for the managed bean. The so-called managed Bean, in fact, is a container as a managed component of some Java classes, which in the CDI and JavaServer faces has been widely used. In addition, the specification introduces EJB Lite so that we can use the EJB session bean outside the full Java EE container, which means that three concepts can exist independently of the Java EE platform. Similar concepts have long existed in those widely used frameworks, such as spring and seam. The Managed bean supports some basic services, such as resource injection, lifecycle callbacks, interceptors, and so on. Other specifications can be built on that definition and add other services, such as CDI adding dependency injection, EJB session Bean Adding things, remote, and so on. Roberto Chinnic on its blog The following example: Given a Jax-rs resource class, you can add a @managedbean annotation, an EJB component annotation (@Stateful), or A CDI annotation (such as @default) converts it to a managed Bean. Conversely, if a given class comes from a managed bean or EJB component, then we can convert it to a Jax-rs resource class by adding a jax-rs @Path annotation. By the way, the Servlet, Jax-ws endpoint class, or any other component type in (most) Java EE 6 can do this.

While the impact of the current managed bean specification is not significant, it is important because it hints at Sun's idea of how to walk the entire Java EE platform. While it is also necessary to modify the specification so that the entire Java EE platform meets its requirements, it is easy to see that the annotated programming model introduced by the managed Bean and Java EE 5 Platform ultimately allows developers to choose from the many services and components provided by the Java EE container. At the same time, the simple managed bean model complements the extension points and service provider interfaces under the platform, providing a standardized mechanism for Java frameworks and product developers to tier on the platform, one of the main goals of the Java EE 6 platform.

Sun GlassFish V3 is likely to be the first application server to provide full platform support, and its preview has now been released. The next beta release of JBoss 5.2 will provide some Java EE 6 support, including JavaServer Faces (JSF) 2.0, Java persistence (JPA) API 2.0, Bean validation, and a new version of CDI. SpringSource also announced support for some of the new standards. Spring 3.0 will support JSF 2.0, JPA 2, Bean validation, and JSR-330. The future spring 3.x will support the Java EE 6 other APIs, including Servlet 3.

For IDE support, NetBeans 6.8 will support JSF 2.0 (including facelets), JPA 2.0, and incremental deployments for GlassFish V3. Now NetBeans 6.8 M2 is already available for download. JetBrains also closely follow the Java EE 6 change, IntelliJ idea 9 will support JPA 2.0, EJB 3.1, JSF 2.0, Servlet 3, CDI, Bean validation, and GlassFish 3.

View English Original: Java EE 6 proposed Final Draft hints at Future Direction of the Platform

Turn from: HTTP://WWW.INFOQ.COM/CN/NEWS/2009/10/EE6PFD