How to create Custom Validation in Spring

https://grokonez.com/spring-framework/create-custom-validation-spring

How to create Custom Validation in Spring

In the post How to perform Form Validation with Spring Boot, we have already made a form validation. Today we're gonna look at a way to create Custom Validation with that Form in Spring.

I. Technology

• Java 1.8
• Maven 3.3.9
• Spring Tool Suite – Version 3.8.1.RELEASE
• Spring Boot: 1.5.1.RELEASE

  II. Overview

  1. Goal

  Create a Custom Validation Annotation @ValidEmail that helps to validate field String email on server-side:

  @ValidEmail(min = 10, message = "Please enter a valid email.")
  private String email;
  

  2. Project Structure

  
• WebController is a Controller which has request mapping methods to display our page.
• RequestInfo is a Data Model Class with annotation for validation.
• ValidEmail is an Annotation Class refers to ValidEmailValidator class.
• ValidEmailValidator is a Constraint Class which implements ConstraintValidator interface.
• webapp folder contains all necessary JSP file and static resource.
• application.properties contains settings for prefix and suffix for JSP files.
• Dependencies for Spring Boot, Tomcat Embed Jasper and Common Validator in pom.xml.

  3. Step to do

  - Create Spring Boot project & add Dependencies - Create jsp file and static resource
• Set prefix and suffix resolution
• Create @ValidEmail Annotation
• Create Constraint Class - Create Data Model Class - Create Web Controller - Run Spring Boot Application & Enjoy Result

  III. Practice

  1. Create Spring Boot project & add Dependencies

  Open Spring Tool Suite, on Menu, choose File -> New -> Spring Starter Project, then fill each fields. Remember that we will the Packaging is War. Click Next, then click Finish.

Open pom.xml and add Dependencies:

https://grokonez.com/spring-framework/create-custom-validation-spring

How to create Custom Validation in Spring