Technology is tough! How do you do it all? Even if you are a technology company or a technology consulting firm, you will find that you have to focus on one or a few core competencies if you want to ensure that you have the latest skills and knowledge in that one area or in a few areas or about a few products or services (if you are lucky).
Every designer and developer knows that user input Validation is a vital part of development for any application. Since the inception of the various MVC frameworks like Struts, Spring, JSF etc., the method of implementing validation has been included in application design considerations. These frameworks set the standards for implementing validation by providing the necessary supporting classes, and certainly, having clean design for validation has its benefits with respect to application maintenance.Prior to the release of version 3.0 of Spring, validation implementation required that the validator class is registered using a Spring configuration XML file. In addition, developer had to validate the fields and ensure error registration using ValidationUtils in the validate() method of the validator class. After the introduction of annotations in Spring 3.0, implementation of validation was simpler and cleaner. Developers can reduce the code by using the Hibernate Validator framework along with Spring. As of this writing, the latest version of the Hibernate Validator Framework is 5.0, which is the reference implementation of JSR-303). The following illustrates the implementation of constraints and validation using JSR-303 annotations:
JAR Dependencies: You’ll need to put the JAR files from Hibernate Validator Framework in the application classpath, which is WEB-INF/lib in a Java Web Project. Hibernate Validator 5.0 ships with a number of various JARs. While some are optional, the following are required JARs for validation implementation.
hibernate-validator-5.1.0.Final
validation-api-1.1.0.Final
classmate-1.0.0
jboss-logging-3.1.3.GA
Annotate model properties: Once you have entered the above JARs in the classpath, you can use the annotations provided by them. The following is an example of a model class where you would need to annotate the properties with required constraints. Note how @Size and @NotEmpty are used.
