Spring Boot Validation

영상 링크
JSR 380: Bean Validation 2.0
- https://beanvalidation.org/2.0/spec/
JSR 303: Bean Validation 1.0
- https://beanvalidation.org/1.0/spec/

Form

Controller
- @ModelAttribute

@PostMapping("/greeting")
public String greetingSubmit(@ModelAttribute Greeting greeting, Model model) {
  model.addAttribute("greeting", greeting);
  return "result";
}

public class Greeting {
  private long id;
  private String content;
  // getters and setters
}

<form action="#" th:action="@{/greeting}" th:object="${greeting}" method="post">
    <p>Id: <input type="text" th:field="*{id}"/></p>
    <p>Message: <input type="text" th:field="*{content}"/></p>
    <p><input type="submit" value="Submit"/> <input type="reset" value="Reset"/></p>
</form>

Validation

public class PersonForm {

	@NotNull
	@Size(min=2, max=30)
	private String name;

	@NotNull
	@Min(18)
	private Integer age;

  // getters and setters
}

@PostMapping("/")
public String checkPersonInfo(@Valid PersonForm personForm, BindingResult bindingResult) {
  if (bindingResult.hasErrors()) {
    return "form";
  }
  return "redirect:/results";
}

<form action="#" th:action="@{/}" th:object="${personForm}" method="post">
  <table>
    <tr>
      <td>Name:</td>
      <td><input type="text" th:field="*{name}" /></td>
      <td th:if="${#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>

Validation Annotations JSR380

@NotNull
@AssertTrue
@Size
@Min
@Max
@Email
@NotEmpty: not null, not empty of String, Collection, Map or Array values
@NotBlank: not null or no whitespace
@Positive, @PositiveOrZero
@Negative, @NegativeOrZero
@Past, @PastOrPresent: date value
@Future, @FutureOrPresent

List<@NotBlank String> preferences;

ref

https://www.baeldung.com/javax-validation
https://spring.io/guides/gs/handling-form-submission/
https://spring.io/guides/gs/validating-form-input/
Customize Validation Error Message
- https://www.baeldung.com/spring-custom-validation-message-source
- https://www.baeldung.com/javax-validation