spring mvc:数据验证
做学生登录信息必填项验证。
student信息有:id,姓名,年龄
Student.java
public class Student { private Integer id; private Integer age; private String name; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } }
StudentValidator.java数据验证代码
import org.springframework.stereotype.Service; import org.springframework.validation.Errors; import org.springframework.validation.ValidationUtils; import org.springframework.validation.Validator; @Service public class StudentValidator implements Validator { public boolean supports(Class<?> clazz){ return Student.class.isAssignableFrom(clazz); } public void validate(Object target, Errors errors) { ValidationUtils.rejectIfEmptyOrWhitespace(errors, "name", "required.name","Field name is required."); } }
注意:StudentValidator 需要加@Service注解,否则自动装载会报错,找不到bean
自动注入的时候,找不到对应的bean
原因是:对应要注入的实现类没有 加注解,如dao层 @Repository 如service层 @Service
StudentController.java
import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Controller; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.bind.WebDataBinder; import org.springframework.web.bind.annotation.InitBinder; import org.springframework.web.bind.annotation.ModelAttribute; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.ui.Model; import org.springframework.validation.BindingResult; import org.springframework.validation.Validator; import org.springframework.validation.annotation.Validated; @Controller public class StudentController { @Autowired @Qualifier("studentValidator") private Validator validator; @InitBinder private void initBinder(WebDataBinder binder) { binder.setValidator(validator); } //前端from数据引用:commandName @ModelAttribute("student") public Student createStudentModel() { return new Student(); } @RequestMapping(value = "/student", method = RequestMethod.GET) public ModelAndView student() { return new ModelAndView("student", "command", new Student()); } @RequestMapping(value = "/addStudent", method = RequestMethod.POST) public String addStudent(@ModelAttribute("student") @Validated Student student, BindingResult bindingResult, Model model) { if (bindingResult.hasErrors()) { return "student"; } model.addAttribute("name", student.getName()); model.addAttribute("age", student.getAge()); model.addAttribute("id", student.getId()); return "student_result"; } }
下面来看看jsp代码
student.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <%@ taglib uri="http://www.springframework.org/tags/form" prefix="form"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <%@ page isELIgnored="false" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Spring MVC表单处理</title> </head> <style> .error { color: #ff0000; } .errorStyle { color: #000; background-color: #ffEEEE; border: 3px solid #ff0000; padding: 8px; margin: 16px; } </style> <body> <h2>学生信息</h2> <form:form method="POST" action="/hello/addStudent" commandName="student"> <form:errors path="*" cssClass="errorStyle" element="div" /> <table> <tr> <td><form:label path="name">姓名:</form:label></td> <td><form:input path="name" /></td> <td><form:errors path="name" cssClass="error" /></td> </tr> <tr> <td><form:label path="age">年龄:</form:label></td> <td><form:input path="age" /></td> </tr> <tr> <td><form:label path="id">编号:</form:label></td> <td><form:input path="id" /></td> </tr> <tr> <td colspan="2"><input type="submit" value="提交" /></td> </tr> </table> </form:form> </body> </html>
这一块的代码:<form:form method="POST" action="/hello/addStudent" commandName="student">,其中commandName中的student是,studentController中的createStudentModel的定义.
这一块的代码:<form:errors path="*" cssClass="errorStyle" element="div" />,cssClass为样式代码,element元素为div.
student_result.jsp
<%@ page contentType="text/html; charset=UTF-8" %> <%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> <%@ page isELIgnored="false" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>spring mvc表单处理</title> </head> <body> <h2>提交的学生信息</h2> <table> <tr> <td>名称:</td> <td>${name}</td> </tr> <tr> <td>年龄:</td> <td>${age}</td> </tr> <tr> <td>编号:</td> <td>${id}</td> </tr> </table> </body> </html>