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