HTML form

Understand the idea

action selects the destination and method selects GET or POST. An input’s name is its submitted parameter key. Unchecked checkboxes submit no value. Browser validation improves usability, while the server must still validate.

A concrete example

<form action="hello" method="get">
  <input name="name">
  <button>Send</button>
</form>

In the application

The welcome page submits a greeting name; JSP forms submit task mutations with CSRF fields.

Do not use GET links for destructive actions. Form submission and AJAX/JSON submission have different default body formats.

See it in a working stage

• Stage 5: submit a form and return the answer directly

Related concepts

• Request parameters
• HTTP
• Bean Validation
• CSRF · Cross-Site Request Forgery