Joda Beans

Joda-Beans provides a small framework that adds properties to Java, greatly enhancing JavaBeans. The key concept is to allow each property on a bean to be accessed as an object. This enables technologies such as XPath, XML conversion, DB mappings, WebApp validation and Swing bindings.

Joda-Beans is unreleased at present. Stable tagged versions are available in GitHub.

Why Joda Beans?

Joda-Beans has been created to plug a gap in the Java language - properties. The concept of properties is familiar to those coding in almost every other modern language. Java stands alone in its pursuit of the terrible JavaBean approach, and personally I believe that properties should have been added to Java before generics and closures.

JavaBeans are typically created by manual coding or one-off IDE generation, such as by Eclipse. The same approach is taken to the creation of equals and hashCode methods. However, none of these approaches provides for a simple and fast mechanism to query a bean for the properties it exposes.

Joda-Beans provides a solution. As a developer, you just write the fields much as you would today. Then you add annotations to the bean and properties. Finally, you run a code generator, which creates the get/set methods plus framework methods that allow the properties to be effectively queried. A key point is that the code generator may be run again and again on the Java file, and is non-destructive.

See these sample classes used for testing - basic Person class, example usage, example of validation.

Documentation

Various documentation is available:

Support

Support on bugs, library usage or enhancement requests is available via:

  • the joda-beans-interest mailing list. Due to spam, you must be subscribed to post to the mailing list.
  • the joda-beans sourceforge forum.

Please contact the project lead, Stephen Colebourne via scolebourne joda org.