Spring Boot教程第19篇:验证表单信息

这篇文篇主要简述如何在springboot中验证表单信息。在springmvc工程中,需要检查表单信息,表单信息验证主要通过注解的形式。

构建工程

创建一个springboot工程,由于用到了 web 、thymeleaf、validator、el,引入相应的起步依赖和依赖,代码清单如下:

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

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
</dependency>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-el</artifactId>
</dependency>
</dependencies>

创建一个PresonForm的Object类

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package com.forezp.entity;

import javax.validation.constraints.Min;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
/**
* Created by chris on 2017/4/19.
*/
public class PersonForm {

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

@NotNull
@Min(18)
private Integer age;

public String getName() {
return this.name;
}

public void setName(String name) {
this.name = name;
}

public Integer getAge() {
return age;
}

public void setAge(Integer age) {
this.age = age;
}

public String toString() {
return "Person(Name: " + this.name + ", Age: " + this.age + ")";
}
}


这个实体类,在2个属性:name,age.它们各自有验证的注解:

  • @Size(min=2, max=30) name的长度为2-30个字符
  • @NotNull 不为空
  • @Min(18)age不能小于18

创建 web Controller

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@Controller
public class WebController extends WebMvcConfigurerAdapter {

@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/results").setViewName("results");
}

@GetMapping("/")
public String showForm(PersonForm personForm) {
return "form";
}

@PostMapping("/")
public String checkPersonInfo(@Valid PersonForm personForm, BindingResult bindingResult) {

if (bindingResult.hasErrors()) {
return "form";
}

return "redirect:/results";
}
}

创建form表单

src/main/resources/templates/form.html:

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<html>
<body>
<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>
</body>
</html>

注册成功的页面

src/main/resources/templates/results.html:

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html>
<body>
Congratulations! You are old enough to sign up for this site.
</body>
</html>

演示

启动工程,访问http://localhost:8080/:

如果你输入A和15,点击 submit:

如果name 输入N, age为空:

如果输入:forezp. 18

参考资料

https://spring.io/guides/gs/validating-form-input/

源码下载

https://github.com/forezp/SpringBootLearning

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