Spring Boot 2 Thymeleaf服务器端表单验证实现详解

Z时代
2024-01-10
分类：综合

这篇文章主要介绍了Spring Boot" title="Spring Boot">Spring Boot 2 Thymeleaf服务器端表单验证实现详解,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

表单验证分为前端验证和服务器端验证。

服务器端验证方面，Java提供了主要用于数据验证的JSR 303规范，而Hibernate Validator实现了JSR 303规范。

项目依赖加入spring-boot-starter-thymeleaf时，默认就会加入Hibernate Validator的依赖。

开发环境：IntelliJ IDEA 2019.2.2

Spring Boot版本：2.1.8

新建一个名称为demo的Spring Boot项目。

1、pom.xml


<dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-devtools</artifactId>
    </dependency>

2、src/main/java/com/example/demo/User.java


package com.example.demo;
import org.hibernate.validator.constraints.Length;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.Size;
public class User {
  @NotBlank(message = "用户名不能为空")
  String name;
  @Length(min = 11, max = 11, message = "手机号长度必须11位")
  String phone;
  @Size(min = 6, max = 20, message = "密码长度6-20位")
  String password;
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
  public String getPhone() {
    return phone;
  }
  public void setPhone(String phone) {
    this.phone = phone;
  }
  public String getPassword() {
    return password;
  }
  public void setPassword(String password) {
    this.password = password;
  }
}

3、src/main/java/com/example/demo/FormController.java


package com.example.demo;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.validation.ObjectError;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import javax.validation.Valid;
import java.util.List;
@Controller
public class FormController {
  @RequestMapping("/{form}")
  public String form(@PathVariable String form, @ModelAttribute User user){
    return form;
  }
  @PostMapping("/submit")
  public String submit(@Valid User user, BindingResult result){
    if (result.hasErrors()) {
      List<ObjectError> list = result.getAllErrors();
      for (ObjectError error : list) {
        System.out.println(error.getDefaultMessage());
      }
      return "form";
    }
    //业务逻辑处理
    return "form";
  }
}

4、src/main/resources/templates/form.html

前端通过#fields对象输出错误信息有2种方式，1种是在每个字段后面输出，另1种是全部在一起输出。


<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>表单的提交处理</title>
  <style>
    .fieldError{color: red}
  </style>
</head>
<body>
  <form method="post" th:action="@{/submit}" th:object="${user}">
    <table>
      <tr>
        <td>用户名：</td>
        <td><input type="text" th:field="*{name}" />
          <span class="fieldError" th:if="${#fields.hasErrors('*{name}')}" th:errors="*{name}"></span>
        </td>
      </tr>
      <tr>
        <td>手机号：</td>
        <td><input type="text" th:field="*{phone}" />
          <span class="fieldError" th:if="${#fields.hasErrors('*{phone}')}" th:errors="*{phone}"></span>
        </td>
      </tr>
      <tr>
        <td>密码：</td>
        <td><input type="text" th:field="*{password}" />
          <span class="fieldError" th:if="${#fields.hasErrors('*{password}')}" th:errors="*{password}"></span>
        </td>
      </tr>
      <tr>
        <td colspan="2">
          <input type="submit" value="提交" />
          <div th:each="err : ${#fields.errors('*')}">
            <span th:text="${err}" class="fieldError"></span>
          </div>
        </td>
      </tr>
    </table>
  </form>
</body>
</html>