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注释和自定义注释来验证用户输入。
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.nhooo;
import javax.validation.constraints.Max;
import javax.validation.constraints.Min;
import com.nhooo.customvalidation.Password;
public class Employee {
private String name;
//Custom annotation
@Password
private String password;
//Predefined annotation
@Min(value=18, message="must be equal or greater than 18")
@Max(value=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.nhooo;
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;
@Controller
public 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.nhooo.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 message
public String message() default "must contain jtp";
//represents group of constraints
public Class<?>[] groups() default {};
//表示关于注解的附加信息
public Class<? extends Payload>[] payload() default {};
}
5、创建验证器类
PasswordConstraintValidator.java
package com.nhooo.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/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- Provide support for component scanning --> <context:component-scan base-package="com.nhooo" /> <!--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="/WEB-INF/jsp/"></property> <property name="suffix" value=".jsp"></property> </bean> </beans>
8、创建请求的页面
index.jsp
<html> <body> <a href="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="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>
标签：java,String,自定义,Spring,javax,MVC,org,import,public From： https://www.cnblogs.com/cnetsa/p/17060740.html