Spring MVC自定义验证项目示例图解 _SpringMVC

Spring MVC框架允许我们执行自定义验证。在这种情况下, 我们声明自己的注释。我们可以根据自己的业务逻辑执行验证。
Spring MVC自定义验证示例在此示例中, 我们同时使用预定义的批注和自定义批注来验证用户输入。
1.将依赖项添加到pom.xml文件。
pom.xml

< !-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc --> < dependency> < groupId> org.springframework< /groupId> < artifactId> spring-webmvc< /artifactId> < version> 5.1.1.RELEASE< /version> < /dependency> < !-- https://mvnrepository.com/artifact/org.apache.tomcat/tomcat-jasper --> < dependency> < groupId> org.apache.tomcat< /groupId> < artifactId> tomcat-jasper< /artifactId> < version> 9.0.12< /version> < /dependency> < !-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api --> < dependency> < groupId> javax.servlet< /groupId> < artifactId> servlet-api< /artifactId> < version> 3.0-alpha-1< /version> < /dependency> < !-- https://mvnrepository.com/artifact/javax.servlet/jstl --> < dependency> < groupId> javax.servlet< /groupId> < artifactId> jstl< /artifactId> < version> 1.2< /version> < /dependency> < !-- https://mvnrepository.com/artifact/org.hibernate.validator/hibernate-validator --> < dependency> < groupId> org.hibernate.validator< /groupId> < artifactId> hibernate-validator< /artifactId> < version> 6.0.13.Final< /version> < /dependency>

2.创建bean类
Employee.java

package com.srcmini; import javax.validation.constraints.Max; import javax.validation.constraints.Min; import com.srcmini.customvalidation.Password; public class Employee { private String name; //Custom annotation @Password private String password; //Predefined annotation @Min(value=http://www.srcmini.com/18, message="must be equal or greater than 18") @Max(value=http://www.srcmini.com/45, message="must be equal or less than 45") private int age; public String getName() {return name; } public void setName(String name) {this.name = name; } public String getPassword() {return password; } public void setPassword(String password) {this.password = password; } public int getAge() {return age; } public void setAge(int age) {this.age = age; } }

3.创建控制器类
EmployeeController.java

package com.srcmini; import javax.validation.Valid; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.validation.BindingResult; import org.springframework.web.bind.annotation.ModelAttribute; import org.springframework.web.bind.annotation.RequestMapping; @Controllerpublic class EmployeeController { @RequestMapping("/hello") public String showForm(Model theModel) {theModel.addAttribute("emp", new Employee()); return "viewpage"; } @RequestMapping("/helloagain") public String processForm(@Valid @ModelAttribute("emp") Employee emp, BindingResult br) {if (br.hasErrors()) {return "viewpage"; }else {return "final"; } }}

4.创建验证器注释
Password.java

package com.srcmini.customvalidation; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import javax.validation.Constraint; import javax.validation.Payload; @Constraint(validatedBy = PasswordConstraintValidator.class)@Target( { ElementType.METHOD, ElementType.FIELD } )@Retention(RetentionPolicy.RUNTIME)public @interface Password { //error messagepublic String message() default "must contain jtp"; //represents group of constraints public Class< ?> [] groups() default {}; //represents additional information about annotationpublic Class< ? extends Payload> [] payload() default {}; }

5.创建验证器类
PasswordConstraintValidator.java

package com.srcmini.customvalidation; import javax.validation.ConstraintValidator; import javax.validation.ConstraintValidatorContext; public class PasswordConstraintValidator implements ConstraintValidator< Password, String> { public boolean isValid(String s, ConstraintValidatorContext cvc) {boolean result=s.contains("jtp"); return result; }}

6.在web.xml文件中提供控制器的条目
web.xml

< ?xml version="1.0" encoding="UTF-8"?> < web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> < display-name> SpringMVC< /display-name> < servlet> < servlet-name> spring< /servlet-name> < servlet-class> org.springframework.web.servlet.DispatcherServlet< /servlet-class> < load-on-startup> 1< /load-on-startup> < /servlet> < servlet-mapping> < servlet-name> spring< /servlet-name> < url-pattern> /< /url-pattern> < /servlet-mapping> < /web-app>

7.在xml文件中定义bean
spring-servlet.xml

< ?xml version="1.0" encoding="UTF-8"?> < beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/mvchttp://www.springframework.org/schema/mvc/spring-mvc.xsd"> < !-- Provide support for component scanning --> < context:component-scan base-package="com.srcmini" /> < !--Provide support for conversion, formatting and validation --> < mvc:annotation-driven/> < !-- Define Spring MVC view resolver --> < bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> < property name="prefix" value="http://www.srcmini.com/WEB-INF/jsp/"> < /property> < property name="suffix" value="http://www.srcmini.com/.jsp"> < /property> < /bean> < /beans>

8.创建请求的页面
index.jsp

< html> < body> < a href="http://www.srcmini.com/hello"> Click here...< /a> < /body> < /html>

9.创建其他视图组件
viewpage.jsp

< %@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %> < html> < head> < style> .error {color:red} < /style> < /head> < body> < form:form action="helloagain" modelAttribute="emp"> Username: < form:input path="name" /> < br> < br> Password (*): < form:password path="password" /> < form:errors path="password" cssClass="error" /> < br> < br> Age (*): < form:input path="age" /> < form:errors path="age" cssClass="error" /> < br> < br> < input type="submit" value="http://www.srcmini.com/Submit" /> < /form:form> < /body> < /html>

final.jsp

< %@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> < !DOCTYPE html> < html> < body> Username: ${emp.name}< br> < br> Password: ${emp.password}< br> < br> Age: ${emp.age}< br> < br> < /body> < /html>

输出