Migrating to Wicket 6.0

Environment

• Wicket 6.0 requires at least Java 6

Repeaters

• `IDataProvider` was converted to using `long` instead of `int` to better line up with JPA and other persistence frameworks. This has caused a rather large cascade of `int` to `long` changes all over the repeater packages (WICKET-1175).

Form Processing

Validation

• `DateValidator` no longer has static factory methods, use `new DateValidator(min,max)` instead
• `StringValidator` no longer has static factory methods, use `new StringValidator(min, max)` instead
• `StringValidator` will add the `maxlen` attribute if added to a component attached to an input tag
• `AbstractValidator` has been removed
• `ValidationError` now makes creating standard error keys (classname and classname.subtype) easier
• Most validators provide a `decorate(ValidationError, Validatable)` method for overriding how they report errors

Ajax

Use JQuery as a backing library for Wicket Ajax functionality

Apache Wicket needed to improve the implementation of its JavaScript libraries used for Ajax functionality (wicket-ajax.js and wicket-event.js) by using any of the bigger JavaScript libraries and delegate to it the handling of the differences in the browsers (DOM, events, Ajax, ...). After a discussion in the mailing lists the Wicket team decided to use JQuery for that.
For more information read Wicket Ajax

package.properties renamed to wicket-package.properties

The special resource bundle that can contain resources for a whole package has been renamed from package.properties to wicket-package.properties. This prefix will be used for all wicket resources which may collide somehow with resources provided by other frameworks. See WICKET-4211

List of renamed classes and methods

Following the renames in subclasses is easier if the @Override annotations are present. IDE-s, like Eclipse, can be used to add missing @Override annotations before moving to wicket 6.

Here's a table of deprecated classes and methods in Wicket 1.5 and the corresponding replacement in Wicket 6.