HTML Form validation is important part while building a website having form fields.
The input fields need to validated and checked if there are null values.
This post will show you different types of validation possible using Client side browser validation and using JavaScript.
input “required”
The required attribute is a boolean attribute.
When present, it specifies that an input field must be filled out before submitting the form.
For spring MVC it will be like required = “required”
required should primarily be seen as a UI helper only. Data Validation should be done on server side to avoid any breach.
JavaScript Form Validation
Code.
JQuery Validation
Ajax Validation (Back End Validation)
This was a vary a basic tutorial on how validation works.
Stay tuned for complex validation in upcoming posts.
Hope it helps!.
The Web Spark 
This tutorial is really useful. I have used it with form validation in Expressjs middleware . It works well. and I have got the best way from these tutorials. So, Thanks for sharing the knowledge.
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