【发布时间】：2020-10-06 09:42:23
【问题描述】：
我是spring MVC 的新手。为了练习我的技能，我制作了一个示例表单，其元素通过各自的controller 填充。现在检查验证部分，我通过注释使用了所有方法，即@NotNull、@Size、@Valid、@ModelAttribute 和BindingResult 对象。以下是我正在使用的文件。我关注了所有必要的方面，但不知道为什么我看不到红色的验证消息。
学生班
package com.sikka.springmvcworking.custombeans;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
public class Student {
private String firstName;
@NotNull
@Size(min=1,message="is required")
private String lastName;
private String country;
private String course;
private String[] knownOs;
private String[] coutries;
private Map<String,String> countryMap;
private Map<String,String> courseMap;
private Map<String,String> kosMap;
public Student() {
}
public Student(String firstName, String lastName, String country, String course, String[] knownOs, String[] coutries,
Map<String, String> countryMap, Map<String, String> courseMap, Map<String, String> kosMap) {
this.firstName = firstName;
this.lastName = lastName;
this.country = country;
this.course = course;
this.knownOs = knownOs;
this.coutries = coutries;
this.countryMap = countryMap;
this.courseMap = courseMap;
this.kosMap = kosMap;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getCountry() {
return country;
}
public void setCountry(String country) {
this.country = country;
}
public Map<String, String> getCountryMap() {
return countryMap;
}
public void setCountryMap(Map<String, String> countryMap) {
this.countryMap = countryMap;
}
public String getCourse() {
return course;
}
public void setCourse(String course) {
this.course = course;
}
public String[] getKnownOs() {
return knownOs;
}
public void setKnownOs(String[] knownOs) {
this.knownOs = knownOs;
}
public String[] getCoutries() {
return coutries;
}
public void setCoutries(String[] coutries) {
this.coutries = coutries;
}
public Map<String, String> getCourseMap() {
return courseMap;
}
public void setCourseMap(Map<String, String> courseMap) {
this.courseMap = courseMap;
}
public Map<String, String> getKosMap() {
return kosMap;
}
public void setKosMap(Map<String, String> kosMap) {
this.kosMap = kosMap;
}
}
学生控制器类
package com.sikka.springmvcworking.controller;
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;
import java.util.*;
import javax.validation.Valid;
import com.sikka.springmvcworking.custombeans.Student;
@Controller
@RequestMapping("stu")
public class StudentController {
@RequestMapping("studentForm")
public String getStudentForm(Model model) {
Student student = new Student();
Map<String,String> countryMap = new LinkedHashMap<String,String>();
countryMap.put("IN", "INDIA");
countryMap.put("BR", "BRAZIL");
countryMap.put("MX", "MEXICO");
student.setCountryMap(countryMap);
Map<String,String> courseMap = new LinkedHashMap<String,String>();
courseMap.put("java", "JAVA");
courseMap.put(".net", ".NET");
courseMap.put("php", "PHP");
courseMap.put("andr", "ANDROID");
student.setCourseMap(courseMap);
Map<String,String> kosMap = new LinkedHashMap<String,String>();
kosMap.put("win", "WINDOWS");
kosMap.put("lnx", "LINUX");
kosMap.put("mac", "MACINTOSH");
student.setKosMap(kosMap);
model.addAttribute("student", student);
System.out.println("inside STUDENT-FORM");
return "STUDENT-FORM";
}
@RequestMapping("processStudent")
public String outputStudent(@Valid @ModelAttribute("student") Student student, BindingResult bindingResult) {
if(bindingResult.hasErrors()) {
return "redirect:studentForm";
}
return "VIEW-STUDENT";
}
}
学生表格 JSP
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<%@ taglib prefix = "c" uri = "http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
<style>
.error {color: red;}
</style>
</head>
<body>
<form:form action="processStudent" modelAttribute="student">
FirstName : <form:input type="text" path="firstName" placeholder="enter your first name"/><br>
LastName : <form:input type="text" path="lastName" placeholder="enter your last name"/>
<form:errors path="lastName" cssClass="error"/><br>
select country : <form:select path="coutries">
<form:options items="${student.countryMap}"/>
</form:select><br>
select course : <form:radiobuttons path="course" items="${student.courseMap}"/><br>
known OS(s) : <form:checkboxes items="${student.kosMap}" path="knownOs"/><br>
<input type="submit" value="submit">
</form:form>
</body>
</html>
学生提交/查看 Jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<br>
Student Name : ${student.firstName} ${student.lastName} <br>
Student visited countries:<br>
<c:forEach var="t" items="${student.coutries}">
<li> ${t} </li>
</c:forEach><br>
Known OS by student : <br>
<c:forEach var="t" items="${student.knownOs}">
<li> ${t} </li>
</c:forEach><br>
Student course : ${student.course}<br>
</body>
</html>
每次尝试lastName 验证时，我都将其留空。我被重定向到相同的学生表格，但没有错误消息。
有没有办法在这个jsp表单中显示验证错误信息。
【问题讨论】：
-
是否只有
@NotNull被评估？它不包含任何消息，甚至不考虑@Size，因此您不会收到任何消息。试试@NotNull(message = "is required")。 -
试过..但结果相同。重定向时未显示字段验证错误消息。
标签： spring spring-mvc