futil

Some classes I found myself repeating across several projects. Most of this stuff is related to JSF.

Install maven artifact like this:

mvn clean install

then use it in your pom.xml

<dependency>
	<groupId>org.meth4j.futil</groupId>
	<artifactId>futil</artifactId>
	<version>0.3.3</version>
</dependency>

futil-square-validator is an example project.

How can it make your life easier?

• Reliably validate input fields, not only when they are non-empty. FacesValidator will not trigger on empty onput, one of the worst "features" of JSF imo. One way out is to use a FacesConverter instead. To make this easy, the abstract class ValidatingConverter can be extended UDPATE: ValidatingConverter is now a javax.faces.validator.Validator, which will validate empty fields too. For this, javax.faces.VALIDATE_EMPTY_FIELDS must be set to true. This feature was not available before JSF 2.0

• Validating an input field using value from another input field This is a standard JSF feature (using binding and f:attribute tag) and ValidatingConverter makes this especially easy for the case that there is only one attribute per input. The name of the attribute must be org.meth4j.futil.attribute

• Internationalised validation error messages. Simply extend ValidatingConverter and throw an appropriate org.meth4j.futil.ValidatorException. The base name of your message resource bundle must be org.meth4j.futil.messages, unless you put an optional config file /META-INF/services/org.meth4j.futil.properties in your classpath. This file then has to define a propertiy bundle_name, see org.meth4j.futil.properties

• Flash messages that can be used anywhere, in ManagedBeans or servlets. To use this feature a JSF PhaseListener must be registered in faces-config.xml

• Reduce FacesMessage construction boilerplate. Use static methods in class Message.

• In the xhtml: Easily find out if validation has failed for a particular input field. This can be used to change the css class for that field, for instance. example here

• Enforces use of enums for resource bundle message keys

• Load classpath resources as strings or properties objects, in one line, and without checked exceptions. See ResourceLoader

• Provides the convenient interface IKey which represents key-label pairs

• Convert a bunch of IKeys (think enum constants) into a bunch of select items quickly, see this in action here