Weld is the reference implementation (RI) for JSR-299: Java Contexts and Dependency Injection for the Java EE platform (CDI). CDI is the Java standard for dependency injection and contextual lifecycle management. JSR-299 is a Java Community Process (JCP) standard that integrates cleanly with the Java EE platform. Any Java EE 6-compliant application server provides support for JSR-299 (even the web profile).

Weld and the JSR-299 TCK (Technology Compatibility Kit) are developed here at seamframework.org. Both are licensed under the Apache License, Version 2.0.

Using Weld

Supported platforms

Weld has been tested on the following platforms:

JBoss AS 6.0.0.M1
GlassFish 3.0
Apache Tomcat 6
Jetty 6.1
Java SE 5.0 and above

How does Seam relate to Weld/JSR-299?

The two technologies share a common goal of providing a unified, contextual, programming model for Java Web Applications. Both provide integration of EJB and JSF.

However, Seam 3 is a superset of JSR-299. Think of JSR-299 as the core of Seam 3 - it's the basic programming model for your application components, and for the built-in components that make up the Seam framework. Weld is our implementation of this programming model. Based on this programming model, Seam provides a full framework for application development, including integration with various non-standard open source technologies. JSR-299 defines a very powerful framework for portable extensions. Seam 3 is implemented as a set of portable extensions, or modules, for JSR-299, that run in any environment which supports JSR-299 (including any Java EE 6 environment).

The following diagram illustrates the relationship between Seam 2, Seam 3 and Weld/JSR-299:

Seam will continue to be the vehicle which delivers BPM integration, Seam Security, Drools integration, RESTeasy integration, PDF and email templates, Excel generation, etc. You can think of Seam as the goodies. Seam will also contain patches for Java EE, like JSF fixes (yes, still) and Seam-managed persistence.

Keep in mind that CDI is the specification, of which Weld is a straight implementation (no frills).

Want to get involved?

We are always looking for community contributors to help with Weld development. Please check out the information on the Weld Development Page if you'd like to know more.