Demo12Application.java
@SpringBootApplication
public class Demo12Application {
public static void main(String[] args) {
Person u = new Person("a", 18);
System.out.println(u);
SpringApplication.run(Demo12Application.class, args);
}
}
@Data
@AllArgsConstructor
class Person {
@NotNull
@Size(min=2, max=30)
private String name;
@NotNull
@Min(18)
private Integer age;
}
@Controller
class PersonMCVConfig implements WebMvcConfigurer {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/results").setViewName("results");
}
@GetMapping("/")
public String show(Person person) {
return "form";
}
@PostMapping("/")
public String checkPersonInfo(@Valid Person person, BindingResult bindingResult) {
if (bindingResult.hasErrors()) {
return "form";
}
return "redirect:/results";
}
}
resources / form.html
<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<body>
<form action="#" th:action="@{/}" th:object="${person}" method="post">
<table>
<tr>
<td>Name:</td>
<td><input type="text" th:field="*{name}" /></td>
<td th:if="${#fields.hasErrors('name')}" th:errors="*{name}">Name Error</td>
</tr>
<tr>
<td>Age:</td>
<td><input type="text" th:field="*{age}" /></td>
<td th:if="${#fields.hasErrors('age')}" th:errors="*{age}">Age Error</td>
</tr>
<tr>
<td><button type="submit">Submit</button></td>
</tr>
</table>
</form>
</body>
</html>
resources / results.html
<html>
<body>
Congratulations! You are old enough to sign up for this site.
</body>
</html>
run the application to see /form and results