SpringMVC框架下数据的增删改查，数据类型转换，数据格式化，数据校验，错误输入的消息回显

<?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_2_5.xsd" 
id="WebApp_ID" version="2.5">
  
     <!-- 配置SpringMVC的DispatcherServlet -->
    <servlet>
        <servlet-name>springDispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>springDispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
  
    <!-- 配置 HiddenHttpMethodFilter: 把 POST 请求转为 DELETE、PUT 请求 -->
      <filter>
          <filter-name>HiddenHttpMethodFilter</filter-name>
          <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
      </filter>
      
      <filter-mapping>
          <filter-name>HiddenHttpMethodFilter</filter-name>
          <url-pattern>/*</url-pattern>
      </filter-mapping>
  
</web-app>

<?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/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
        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-4.0.xsd">
    
    <!-- 配置自动扫描的包 -->
    <context:component-scan base-package="com.atguigu.springmvc"></context:component-scan>
    
    <!-- 配置视图解析器 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>
    
    <!--  
        default-servlet-handler 将在 SpringMVC 上下文中定义一个 DefaultServletHttpRequestHandler,
        它会对进入 DispatcherServlet 的请求进行筛查, 如果发现是没有经过映射的请求, 就将该请求交由 WEB 应用服务器默认的 
        Servlet 处理. 如果不是静态资源的请求，才由 DispatcherServlet 继续处理

        一般 WEB 应用服务器默认的 Servlet 的名称都是 default.
        若所使用的 WEB 服务器的默认 Servlet 名称不是 default，则需要通过 default-servlet-name 属性显式指定
        
    -->
    <mvc:default-servlet-handler/>
    
    <!-- 一般都会配置这个 <mvc:annotation-driven ></mvc:annotation-driven>，
    由于。。。requestmapping请求实现不了，使用这个，会使requestmapping请求一定实现
    -->
    <mvc:annotation-driven conversion-service="conversionService"></mvc:annotation-driven>
    
    <!-- 配置 ConversionService ,自定义类型转换器,bean配置-->
    <bean id="conversionService"
        class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
        <property name="converters">
            <set>
            <!-- bean。。。为自定义类型转换器的类名，其中，首字母小写 -->
                <ref bean="employeeConverter"/>
            </set>
        </property>    
    </bean>
    
    <!-- 配置国际化资源文件 -->
    <bean id="messageSource" 
        class="org.springframework.context.support.ResourceBundleMessageSource">
        <property name="basename" value="i18n"></property>
    </bean>
    
</beans>

package com.atguigu.springmvc.crud.entities;

public class Department {

    private Integer id;
    private String departmentName;
    
    public Department() {
        super();
        // TODO Auto-generated constructor stub
    }
    
    public Department(Integer id, String departmentName) {
        super();
        this.id = id;
        this.departmentName = departmentName;
    }
    
    
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getDepartmentName() {
        return departmentName;
    }

    public void setDepartmentName(String departmentName) {
        this.departmentName = departmentName;
    }

    @Override
    public String toString() {
        return "Department [id=" + id + ", departmentName=" + departmentName
                + "]";
    }
    
}

package com.atguigu.springmvc.crud.entities;

import java.util.Date;

import javax.validation.constraints.Past;

import org.hibernate.validator.constraints.Email;
import org.hibernate.validator.constraints.NotEmpty;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.format.annotation.NumberFormat;

/*
 * 在封装类的属性上面添加注解，是为了实现类型样式的转换：
 * 步骤：
 * 1>.在封装类的属性上面添加各种注解
 * 2>.在springmvc.xml的配置中添加标配<mvc:annotation-driven></mvc:annotation-driven>，
 * 不管怎样都不影响注解
 * 
 * */
public class Employee {
    
    private Integer id;
    
    @NotEmpty
    private String lastName;

    @Email
    private String email;
    //1 male, 0 female
    private Integer gender;
    
    private Department department;
    
    //@Past注解的作用是：输入是此时间之前的时间，否则抛出错误
    @Past
    @DateTimeFormat(pattern="yyyy-MM-dd")
    private Date birth;
    
    @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 Date getBirth() {
        return birth;
    }

    public void setBirth(Date birth) {
        this.birth = birth;
    }

    public Float getSalary() {
        return salary;
    }

    public void setSalary(Float salary) {
        this.salary = salary;
    }

    @Override
    public String toString() {
        return "Employee [id=" + id + ", lastName=" + lastName + ", email="
                + email + ", gender=" + gender + ", department=" + department
                + ", birth=" + birth + ", 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
    }
    
}

package com.atguigu.springmvc.crud.dao;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.springframework.stereotype.Repository;

import com.atguigu.springmvc.crud.entities.Department;

@Repository//标识持久层组件
public class DepartmentDao {
    
    private static Map<Integer, Department> departments=null;
    
    static{
        departments=new HashMap<Integer, Department>();
        
        departments.put(1001, new Department(1001,"D-AA"));
        departments.put(1002, new Department(1002,"D-BB"));
        departments.put(1003, new Department(1003,"D-CC"));
        departments.put(1004, new Department(1004,"D-DD"));
        departments.put(1005, new Department(1005,"D-EE"));
    }
    
    //获取map集合中的所有值
    public Collection<Department> getDepartments(){
        return departments.values();
    }
    
    //通过id值，获取map集合中的一个值
    public Department getDepartment(Integer id){
        return departments.get(id);
    }
}

package com.atguigu.springmvc.crud.dao;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.atguigu.springmvc.crud.entities.Department;
import com.atguigu.springmvc.crud.entities.Employee;

@Repository//标识持久层组件
public class EmployeeDao {
    
    private static Map<Integer, Employee> employees=null;
    
    @Autowired
    private DepartmentDao departmentDao;
    static{
        employees=new HashMap<Integer, Employee>();
        
        employees.put(1001, new Employee(1001, "E-AA", "aa@163.com", 1, new Department(101, "D-AA")));
        employees.put(1002, new Employee(1002, "E-BB", "bb@163.com", 1, new Department(102, "D-BB")));
        employees.put(1003, new Employee(1003, "E-CC", "cc@163.com", 0, new Department(103, "D-CC")));
        employees.put(1004, new Employee(1004, "E-DD", "dd@163.com", 0, new Department(104, "D-DD")));
        employees.put(1005, new Employee(1005, "E-EE", "ee@163.com", 1, new Department(105, "D-EE")));
    }
    
    private static Integer initId=1006;
    
    //添加数据的方法
    public void save(Employee employee){
        if(employee.getId()==null){
            employee.setId(initId++);
        }
        
        employee.setDepartment(departmentDao.getDepartment(employee.getDepartment().getId()));
        employees.put(employee.getId(), employee);
    }
    
    //获取全部的数据的方法
    public Collection<Employee> getAll(){
        return employees.values();
    }
    
    //获取集合中的一个数据
    public Employee getEmployee(Integer id){
        return employees.get(id);
    }
    
    //删除集合中的一个数据
    public void delect(Integer id){
        employees.remove(id);
    }
}

package com.atguigu.springmvc.crud.handlers;

import java.util.Map;

import javax.validation.Valid;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.validation.Errors;
import org.springframework.validation.FieldError;
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.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

import com.atguigu.springmvc.crud.dao.DepartmentDao;
import com.atguigu.springmvc.crud.dao.EmployeeDao;
import com.atguigu.springmvc.crud.entities.Employee;


@Controller //标识表现层组件
public class EmployeeHandler {
    
    @Autowired
    private DepartmentDao departmentDao;
    
    @Autowired
    private EmployeeDao employeeDao;
    
    //自定义类型转换器,使用这个请求 
    //<!-- lastname-email-gender-department.id 例如: GG-gg@atguigu.com-0-105 -->
    @RequestMapping("/testConversionServiceConverer")
    public String testConverter(@RequestParam("employee") Employee employee){
        employeeDao.save(employee);
        System.out.println("save: " + employee);
        return "redirect:/emps";
        }
    
    /*
     * 在方法定义上使用@ModelAttribute注解：Spring MVC在调用目标处理方法前，
     * 会先逐个调用在方法上标注了@ModelAttribute的方法；即每个方法会先调用 方法上标注的@ModelAttribute的方法
     * 
     * @ModelAttribute作用是：可以从隐含对象中获取隐含的模型数据中获取对象，（就是可以获取jsp中隐含属性的变量值），
     * 在将请求参数绑定到对象中，再传入  入参，将方法入参对象，添加到模型中；
     * */
    @ModelAttribute
    public void getEmployee(@RequestParam(value="id",required=false) Integer id, Map<String, Object> map){
        if(id!=null){
            map.put("employee", employeeDao.getEmployee(id));
        }
    }
    
    //修改操作，将修改好的信息重定向到emps请求
    @RequestMapping(value="/emp", method=RequestMethod.PUT)
    public String update(Employee employee){
        employeeDao.save(employee);
        return "redirect:/emps";
    }
    
    //修改操作，将要修改的信息显示在input.jsp页面上
    @RequestMapping(value="/emp/{id}", method=RequestMethod.GET)
    public String input(@PathVariable("id") Integer id,Map<String, Object> map){
        map.put("employee", employeeDao.getEmployee(id));
        map.put("departments", departmentDao.getDepartments());
        return "input";
    }
    
    //删除操作,然后重定向到/emps请求，即在list.jsp页面显示
    @RequestMapping(value="/emp/{id}", method=RequestMethod.DELETE)
    public String delete(@PathVariable("id") Integer id){
        employeeDao.delect(id);
        return "redirect:/emps";
    }
    
    //@Valid注解，表单验证时使用;  表单验证时对架包的处理：将
    //hibernate-validator-5.0.0.CR2-dist\hibernate-validator-5.0.0.CR2\dist\lib\required
    //下的三个架包：el-api-2.2，javax.el-2.2.4，javax.el-api-2.2.4 
    //复制到  apache-tomcat-6.0.16\apache-tomcat-6.0.16\lib 目录下  并且彻底粉碎apache-tomcat包 lib中的el架包，这样才可以实现表单的验证
    
    //添加信息操作，如果添加信息的格式正确，然后重定向到/emps请求，即到list.jsp页面；
    //如果添加信息的格式不正确，则跳转到本页面（input.jsp），显示错误的信息，需要在input.jsp页面加入标签
    //<form:errors path="*"></form:errors>,将所有的错误都显示在一块，错误信息的显示，
    //也可以分开写，格式为<form:errors path="lastName"></form:errors>，path值为属性值，分别写在属性值的下边，  显示在 输入错误的文本框下边
    
    @RequestMapping(value="/emp", method=RequestMethod.POST)
    public String save(@Valid Employee employee, Errors result,Map<String, Object> map){
        System.out.println("save"+employee);
        
        if(result.getErrorCount()>0){
            System.out.println("出错了");
            //将所有错误都输出
            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:/emps";
    }
    
    
    //添加员工的信息，将一个空的employee和非空的department放入到map集合中，
    //通过视图解析器，转发到input页面，可以添加信息，是一个GET请求
    @RequestMapping(value="/emp",method=RequestMethod.GET)
    public String input(Map<String, Object> map){
        map.put("departments", departmentDao.getDepartments());
        map.put("employee", new Employee());
        return "input";
    }
    
    //显示employee的全部的信息
    @RequestMapping("/emps")
    public String list(Map<String, Object> map){
        map.put("employees", employeeDao.getAll());
        return "list";
    }
    
    //测试方法
    @RequestMapping("/test")
    public String testTT(){
        return "test";
    }
    
    /*由@InitBinder标识的方法，可以对WebDataBinder初始化，
     * WebDataBinder是DataBinder的子类，用于完成由表单字段到javaBean属性的绑定
     * 
     * @InitBinder注解的方法不能有返回值，它必须声明为void；
     * 方法的参数通常是WebDataBinder；
     * 
     * @InitBinder注解的方法的作用是使该属性在jsp页面上没有值，例如lastName属性在input.jsp页面上没有值
     * */
//    @InitBinder
//    private void initBinder(WebDataBinder binder) {
//        binder.setDisallowedFields("lastName");
//
//    }
    
}

NotEmpty.employee.lastName=^^LastName\u4E0D\u80FD\u4E3A\u7A7A.
Email.employee.email=Email\u5730\u5740\u4E0D\u5408\u6CD5
Past.employee.birth=Birth\u4E0D\u80FD\u662F\u4E00\u4E2A\u5C06\u6765\u7684\u65F6\u95F4. 

typeMismatch.employee.birth=Birth\u4E0D\u662F\u4E00\u4E2A\u65E5\u671F.

package com.atguigu.springmvc.crud.converters;


import org.springframework.core.convert.converter.Converter;
import org.springframework.stereotype.Component;


import com.atguigu.springmvc.crud.entities.Department;
import com.atguigu.springmvc.crud.entities.Employee;


@Component
public class EmployeeConverter implements Converter<String, Employee>{

    @Override
    //自定义类型转换器
    public Employee convert(String source) {
        if(source!=null){
            //GG-gg@atguigu.com-0-105
            String [] vals=source.split("-");
            if(vals!=null && vals.length==4){
                String lastName = vals[0];
                String email = vals[1];
                Integer gender = Integer.parseInt(vals[2]);
                
                Department department = new Department();
                department.setId(Integer.parseInt(vals[3]));
                
                Employee employee = new Employee(null, lastName, email, gender, department);
                System.out.println(source + "--convert--" + employee);
                return employee;
            }
            
        }
        return null;
    }

}

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!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>Insert title here</title>
</head>
<body>
    
    <center>
    
    <a href="emps">List All Employees</a>
    <br><br>
    
    <a href="test">TTTTTTT</a>
    </center>
    
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<!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>Insert title here</title>
<!--  
    SpringMVC 处理静态资源:
    1. 为什么会有这样的问题:
    优雅的 REST 风格的资源URL 不希望带 .html 或 .do 等后缀
    若将 DispatcherServlet 请求映射配置为 /, 
    则 Spring MVC 将捕获 WEB 容器的所有请求, 包括静态资源的请求, SpringMVC 会将他们当成一个普通请求处理, 
    因找不到对应处理器将导致错误。
    2. 解决: 在 SpringMVC 的配置文件中配置 <mvc:default-servlet-handler/>
    和 <mvc:annotation-driven></mvc:annotation-driven>，
-->
<script type="text/javascript" src="scripts/jquery-1.9.1.min.js"></script>
<script type="text/javascript">
    $(function(){
        $(".delete").click(function(){
            var href=$(this).attr("href");
            $("form").attr("action",href).submit();
            return false;
        });
    })
    
</script>

</head>
<body>
    
    <!-- 
    一个超链接是一个get请求，用jQuery方法和影藏的表单的方法，
    将get请求转化为post请求，再将post请求转换为delete请求（web.xml文件中进行了配置）
    -->
    <form action="" method="post">
        <input type="hidden" name="_method" value="DELETE"/>
    </form>
    
    <center>
    
    <c:if test="${empty requestScope.employees }">
        没有任何员工信息!!!
    </c:if>
    <br><br>
    
    <c:if test="${!empty requestScope.employees }">
        <table border="1" cellpadding="10" cellspacing="0">
            <tr>
                <th>ID</th>
                <th>ListName</th>
                <th>Email</th>
                <th>Gender</th>
                <th>Department</th>
                <th>Edit</th>
                <th>Delete</th>
            </tr>
            
            <c:forEach items="${requestScope.employees }" var="emp">
            <tr>
                <td>${emp.id }</td>
                <td>${emp.lastName }</td>
                <td>${emp.email }</td>
                <td>${emp.gender==0 ? ‘Female‘ : ‘Male‘ }</td>
                <td>${emp.department.departmentName }</td>
                <td> <a href="emp/${emp.id }">Edit</a> </td>
                <td> <a  class="delete" href="emp/${emp.id }">Delete</a> </td>
            </tr>
            </c:forEach>
                
        </table>    
    </c:if>
    
    <br><br>
    <a href="emp">And New Employee</a>
    
    </center>
    
</body>
</html>

<%@page import="java.util.HashMap"%>
<%@page import="java.util.Map"%>
<%@ 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 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>Insert title here</title>
</head>
<body>

    <form action="testConversionServiceConverer" method="post">
        <!-- lastname-email-gender-department.id 例如: GG-gg@atguigu.com-0-105 -->
        Employee:<input type="text" name="employee"/>
        <input type="submit" value="Submit"/>
    </form>
    
    <br>
    <!--  
        1. WHY 使用 form 标签呢 ?
        可以更快速的开发出表单页面, 而且可以更方便的进行表单值的回显
        2. 注意:
        可以通过 modelAttribute 属性指定绑定的模型属性,
        若没有指定该属性，则默认从 request 域对象中读取 command 的表单 bean
        如果该属性值也不存在，则会发生错误。
    -->
    
    <!-- 添加员工的信息的jsp -->
    <form:form action="${pageContext.request.contextPath }/emp" method="post" modelAttribute="employee">
        <!-- path 属性对应 html 表单标签的 name 属性值 -->
        
        <form:errors path="*"></form:errors>//所有的校验信息显示在一块
        <br><br>
        <c:if test="${employee.id==null }">
            lastName:<form:input path="lastName"/>
            <form:errors path="lastName"></form:errors>//分别显示校验信息
        </c:if>
        
        <c:if test="${employee.id!=null }">
            <form:hidden path="id"/>

            <!-- 将post请求转换为put请求，put请求即为更改 -->
            <input type="hidden" name="_method" value="PUT"/>
            
            <%-- 对于 _method 不能使用 form:hidden 标签, 因为 modelAttribute 对应的 bean 中没有 _method 这个属性 --%>
            <%-- 
            <form:hidden path="_method" value="PUT"/>
            --%>
        </c:if>
        
        <br><br>
        Email:<form:input path="email"/>
        <form:errors path="email"></form:errors>
        
        <br><br>
        
        <%
            Map<String, String> genders=new HashMap<String, String>();
            genders.put("1", "Male");
            genders.put("0", "Female");
            
            request.setAttribute("genders", genders);
        %>
        Gender:
        <br>
        <form:radiobuttons path="gender" items="${genders }" delimiter="<br>"/>
        <br><br>
        
        Department:<form:select path="department.id" 
            items="${departments }" itemLabel="departmentName" itemValue="id"></form:select>
        <br><br>
        <!--  
            1. 数据类型转换
            2. 数据类型格式化
            3. 数据校验. 
            1). 如何校验 ? 注解 ?
            ①. 使用 JSR 303 验证标准
            ②. 加入 hibernate validator 验证框架的 jar 包
            ③. 在 SpringMVC 配置文件中添加 <mvc:annotation-driven />
            ④. 需要在 bean 的属性上添加对应的注解
            ⑤. 在目标方法 bean 类型的前面添加 @Valid 注解
            2). 验证出错转向到哪一个页面 ?
            注意: 需校验的 Bean 对象和其绑定结果对象或错误对象时成对出现的，它们之间不允许声明其他的入参
            3). 错误消息 ? 如何显示, 如何把错误消息进行国际化
        -->
        
        Birth: <form:input path="birth"/>
        <form:errors path="birth"></form:errors>
        
        <br><br>
        Salary: <form:input path="salary"/>
        <form:errors path="salary"></form:errors>
        
        <br><br>
        <input type="submit" value="Submit"/>
    </form:form>
    
</body>
</html>