1）每个属性在数据绑定和数据校验发生错误时，都会生成一个对应的FieldError对象
2）当属性校验失败后，校验框架会为该属性生成4个消息代码，
这些代码以校验注解类名为前缀，结合modleAttribute、属性名及属性类型名生成多个
对应的消息代码：例如User类中的password属性使用@Pattern注解，当该值不满足@Pattern所定义的规则时
产生以下4个错误代码
-Pattern.user.password
-Pattern.password
-Pattern.java.lang.String
-Pattern
3)当使用springmvc标签显示错误消息时，springmvc会查看web上下文是否装配对应国际化消息
如果没有，会显示默认错误消息，否则使用国际化
4)当数据类型转换或数据格式转换发生错误，或该有的参数不存在，或调用处理方法时发生错误，
都会在隐含模型中创建错误消息，错误代码前缀说明如下：
-required：参数必须，如@RequiredParam（“param1”）标注一个入参，但该参数不存在
-typeMismatch：数据绑定时，发生类型不匹配问题
-methodInvocation：调用处理方法时发生错误
注意：调用了Hibernate-validate验证，别忘注解@validate哦
@RequestMapping(value={"/emp","/emp/add"}, method=RequestMethod.POST)
private String add(@Valid Employee employee, BindingResult result,
Map<String, Object> map){
System.out.println(employee.toString());
if(result.getErrorCount() > 0) {
System.out.println("出错了");
for(FieldError error : result.getFieldErrors()) {
System.out.println(error.getField() + " : " + error.getDefaultMessage());
}
//若验证出错, 则转向定制的页面
map.put("departments", departmentDao.getDepartments());
return "input";
}
employeeDao.save(employee);
return "redirect:/list";
}
i18n.properties国际化文件
Email.employee.email=邮箱格式不正确 Past.employee.birthday=日期过时 NotNull.employee.lastName=不能为空 typeMismatch.employee.birthday=日期转换错误
要验证的bean
package com.hous.crud.bean;
import java.util.Date;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Past;
import org.hibernate.validator.constraints.Email;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.format.annotation.NumberFormat;
public class Employee {
private Integer id;
@NotNull
private String lastName;
@Email
private String email;
//1 male, 0 female
private Integer gender;
private Department department;
@Past
@DateTimeFormat(pattern="yyyy-MM-dd")
private Date birthday;
@NumberFormat(pattern="#,###,###.#")
private Float salary;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Integer getGender() {
return gender;
}
public void setGender(Integer gender) {
this.gender = gender;
}
public Department getDepartment() {
return department;
}
public void setDepartment(Department department) {
this.department = department;
}
public Float getSalary() {
return salary;
}
public void setSalary(Float salary) {
this.salary = salary;
}
public Employee(Integer id, String lastName, String email, Integer gender,
Department department) {
super();
this.id = id;
this.lastName = lastName;
this.email = email;
this.gender = gender;
this.department = department;
}
public Employee() {
// TODO Auto-generated constructor stub
}
/**
* @return the birthday
*/
public Date getBirthday() {
return birthday;
}
/**
* @param birthday the birthday to set
*/
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "Employee [id=" + id + ", lastName=" + lastName + ", email=" + email + ", gender=" + gender
+ ", department=" + department + ", birthday=" + birthday + ", salary=" + salary + "]";
}
}
springmvc.xml添加国际化配置
<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource"> <property name="basename" value="i18n"></property> </bean>
<%@ page import="java.util.*"%>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>添加雇员信息</title>
</head>
<body>
<!--
1.why使用form标签
快速开发页面，方便表单值的回显
2.注意
可以通过modelAttribute指定绑定的模型类型
若没有指定，则读取request的commond的表单bean
若该属性值也不存在则报错
-->
<form:form action="${pageContext.request.contextPath}/emp" method="POST" modelAttribute="employee">
<table>
<form:errors path="*"/>
<!-- id为整数类型 -->
<c:if test="${employee.id == null }">
<tr><th>First name</th><td><form:input path="lastName"/></td><td><form:errors path="lastName"/></td></tr>
</c:if>
<c:if test="${employee.id != null }">
<form:hidden path="id"/>
<input type="hidden" value="PUT" name="_method"/>
</c:if>
<tr><th>Email</th><td><form:input path="email"/></td><td><form:errors path="email"/></td></tr>
<%
Map<String, String> genders = new HashMap<String, String>();
genders.put("0","Male");
genders.put("1","Female");
request.setAttribute("genders", genders);
%>
<tr><th>Gender</th><td><form:radiobuttons path="gender" items="${genders }"/></td></tr>
<tr><th>Department</th><td><form:select path="department.id" items="${depts}"
itemLabel="departmentName" itemValue="id" /></td></tr>
<tr><th>birthday</th><td><form:input path="birthday"/></td><td><form:errors path="birthday"/></td></tr>
<tr><th>salary</th><td><form:input path="salary"/></td><td><form:errors path="salary"/></td></tr>
</table>
<input type="submit" value="提交"/>
</form:form>
</body>
</html>