Spring Boot lets you define your own error view instead of the Whitelabel error page that we saw earlier. It must have the name error and its purpose is to handle all exceptions. The default BasicErrorController class will expose a lot of useful model attributes that you can display on this page.
Let's create a custom error page in src/main/resources/templates. Let's call it error.html:
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head lang="en">
<meta charset="UTF-8"/>
<title th:text="${status}">404</title>
<link href="/webjars/materializecss/0.96.0/css/materialize.css" type="text/css" rel="stylesheet"
media="screen,projection"/>
</head>
<body>
<div class="row">
<h1 class="indigo-text center" th:text="${error}">Not found</h1>
<p class="col s12 center" th:text="${message}">
This page is not available
</p>
</div>
</body>...