RESTRUL_CRUD_需求 显示所有员工信息 URI：emps请求方式：GET显示效果

添加员工信息 显示添加页面：URI：emp请求方式：GET显示效果

添加员工信息：URI：emp请求方式：POST显示效果：完成添加，重定向到 list 页面。

删除操作 URL：emp/{id}请求方式：DELETE删除后效果：对应记录从数据表中删除 修改操作：lastName 不可修改！显示修改页面 URI：emp/{id}请求方式：GET显示效果：回显表单。 修改员工信息 URI：emp 请求方式：PUT显示效果：完成修改，重定向到 list 页面。

相关的类

省略了Service层，为了教学方便

实体类：Employee、DepartmentHandler：EmployeeHandlerDao：EmployeeDao、DepartmentDao

相关的页面 list.jspinput.jspedit.jsp RESTRUL_CRUD_显示所有员工信息 搭建开发环境 拷贝jar包

com.springsource.net.sf.cglib-2.2.0.jar

com.springsource.org.aopalliance-1.0.0.jar

com.springsource.org.aspectj.weaver-1.6.8.RELEASE.jar

spring-aop-4.0.0.RELEASE.jar

spring-aspects-4.0.0.RELEASE.jar

commons-logging-1.1.3.jar

spring-beans-4.0.0.RELEASE.jar

spring-context-4.0.0.RELEASE.jar

spring-core-4.0.0.RELEASE.jar

spring-expression-4.0.0.RELEASE.jar

spring-jdbc-4.0.0.RELEASE.jar

spring-orm-4.0.0.RELEASE.jar

spring-tx-4.0.0.RELEASE.jar

spring-web-4.0.0.RELEASE.jar

spring-webmvc-4.0.0.RELEASE.jar

创建配置文件:springmvc.xml  增加context,mvc,beans名称空间。

<?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">

 

<!-- 配置扫描的包：com.atguigu.springmvc.crud -->

<context:component-scan base-package="com.atguigu.springmvc"/>

 

<!-- 配置视图解析器：默认采用转发 -->

<bean id="internalResourceViewResolver"

class="org.springframework.web.servlet.view.InternalResourceViewResolver">

<property name="prefix" value="/WEB-INF/views/"/>

<property name="suffix" value=".jsp"></property>

</bean> 

</beans>

配置核心控制器：web.xml

<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>

将 POST 请求转换为 PUT 或 DELETE 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>

创建相关页面

/WEB-INF/views/list.jsp

index.jsp

增加实体类

增加DAO类

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

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;

public void save(Employee employee){

if(employee.getId() == null){

employee.setId(initId++);

} 

employee.setDepartment(departmentDao.getDepartment(

employee.getDepartment().getId()));

employees.put(employee.getId(), employee);

}

public Collection<Employee> getAll(){

return employees.values();

}

public Employee get(Integer id){

return employees.get(id);

}

public void delete(Integer id){

employees.remove(id);

}

}

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

public class DepartmentDao {

private static Map<Integer, Department> departments = null;

static{

departments = new LinkedHashMap<Integer, Department>();

departments.put(101, new Department(101, "D-AA"));

departments.put(102, new Department(102, "D-BB"));

departments.put(103, new Department(103, "D-CC"));

departments.put(104, new Department(104, "D-DD"));

departments.put(105, new Department(105, "D-EE"));

}

public Collection<Department> getDepartments(){

return departments.values();

}

public Department getDepartment(Integer id){

return departments.get(id);

}

}

显示所有员工信息 增加页面链接

<a href="empList">To Employee List</a>

增加处理器

package com.atguigu.springmvc.crud.handlers;

import java.util.Map;

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

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import com.atguigu.springmvc.crud.dao.EmployeeDao;

@Controller

public class EmployeeHandler {

@Autowired

private EmployeeDao employeeDao ;

@RequestMapping("/empList")

public String empList(Map<String,Object> map){

map.put("empList", employeeDao.getAll());        //默认存放到request域中        

return "list";

} 

}

SpringMVC中没遍历的标签，需要使用jstl标签进行集合遍历增加jstl标签库jar包

<%@ 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>

</head>

<body>

<c:if test="${empty requestScope.empList }">

对不起，没有找到任何员工！

</c:if>

<c:if test="${!empty requestScope.empList }">

<table border="1" cellpadding="10" cellspacing="0">                

<tr>

<td>EmpId</td>

<td>LastName</td>

<td>Gender</td>

<td>Email</td>

<td>DepartmentName</td>

<td>Edit</td>

<td>Delete</td>

</tr>

<c:forEach items="${requestScope.empList }" var="emp">

<tr>

<td>${emp.id }</td>

<td>${emp.lastName }</td>

<td>${emp.gender==0?"Female":"Male" }</td>

<td>${emp.email }</td>

<td>${emp.department.departmentName }</td>

<td><a href="">Edit</a></td>

<td><a href="">Delete</a></td>

</tr>                

</c:forEach>        

</table>

</c:if>

</body>

</html>

RESTRUL_CRUD_添加操作&表单标签 在list.jsp上增加连接

<a href="empInput">Add Employee</a>

增加处理器方法

@RequestMapping(value="/empInput",method=RequestMethod.GET)

public String empInput(Map<String,Object> map){

map.put("deptList", departmentDao.getDepartments());

//解决错误：java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'command' available as request attribute

Employee employee = new Employee();

//map.put("command", employee);

map.put("employee", employee);

return "add";

}

显示添加页面

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

    pageEncoding="UTF-8" import="java.util.*"%>

<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>

<!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>

 

<!--

1.为什么使用SpringMVC的form标签

① 快速开发

② 表单回显

2.可以通过modelAttribute指定绑定的模型属性，

若没有指定该属性，则默认从request域中查找command的表单的bean

如果该属性也不存在，那么，则会发生错误。

 -->

 <form:form action="empAdd" method="POST" modelAttribute="employee">

         LastName : <form:input path="lastName"/><br><br>

         Email : <form:input path="email"/><br><br>

         <%

                 Map<String,String> map = new HashMap<String,String>();

                 map.put("1", "Male");

                 map.put("0","Female");

                 request.setAttribute("genders", map);

         %>

        Gender : <br><form:radiobuttons path="gender" items="${genders }" delimiter="<br>"/><br><br>

         DeptName :

                 <form:select path="department.id"

                                                 items="${deptList }"

                                                 itemLabel="departmentName"

                                                 itemValue="id"></form:select><br><br>

                 <input type="submit" value="Submit"><br><br>

 </form:form> 

</body>

</html>

显示表单信息时，会报错：

HTTP Status 500 -

 

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: An exception occurred processing JSP page /WEB-INF/views/add.jsp at line 18

15:                         ② 表单回显 16:          --> 17:          <form:form action="empAdd" method="POST"> 18:                  LastName : <form:input path="lastName"/> 19:                  Email : <form:input path="email"/> 20:                  <% 21:                          Map<String,String> map = new HashMap<String,String>();

Stacktrace:         org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:505)         org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:410)         org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)         org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)         javax.servlet.http.HttpServlet.service(HttpServlet.java:803)         org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:209)         org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:266)         org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1225)         org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1012)         org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)         org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876)         org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:931)         org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:822)         javax.servlet.http.HttpServlet.service(HttpServlet.java:690)         org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807)         javax.servlet.http.HttpServlet.service(HttpServlet.java:803)         org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)         org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)

root cause

java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'command' available as request attribute         org.springframework.web.servlet.support.BindStatus.<init>(BindStatus.java:141)

使用 Spring的表单标签

通过 SpringMVC 的表单标签可以实现将模型数据中的属性和 HTML 表单元素相绑定，以实现表单数据更便捷编辑和表单值的回显form 标签 一般情况下，通过 GET 请求获取表单页面，而通过 POST 请求提交表单页面，因此获取表单页面和提交表单页面的 URL 是相同的。只要满足该最佳条件的契约，<form:form> 标签就无需通过 action 属性指定表单提交的 URL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。SpringMVC 提供了多个表单组件标签，如 <form:input/>、<form:select/> 等，用以绑定表单字段的属性值，它们的共有属性如下： path：表单字段，对应 html 元素的 name 属性，支持级联属性htmlEscape：是否对表单值的 HTML 特殊字符进行转换，默认值为 truecssClass：表单组件对应的 CSS 样式类名cssErrorClass：表单组件的数据存在错误时，采取的 CSS 样式form:input、form:password、form:hidden、form:textarea：对应 HTML 表单的 text、password、hidden、textarea 标签form:radiobutton：单选框组件标签，当表单 bean 对应的属性值和 value 值相等时，单选框被选中form:radiobuttons：单选框组标签，用于构造多个单选框 items：可以是一个 List、String[] 或 MapitemValue：指定 radio 的 value 值。可以是集合中 bean 的一个属性值itemLabel：指定 radio 的 label 值delimiter：多个单选框可以通过 delimiter 指定分隔符form:checkbox：复选框组件。用于构造单个复选框form:checkboxs：用于构造多个复选框。使用方式同 form:radiobuttons 标签form:select：用于构造下拉框组件。使用方式同 form:radiobuttons 标签form:option：下拉框选项组件标签。使用方式同 form:radiobuttons 标签form:errors：显示表单组件或数据校验所对应的错误 <form:errors path= “*” /> ：显示表单所有的错误<form:errors path= “user*” /> ：显示所有以 user 为前缀的属性对应的错误<form:errors path= “username” /> ：显示特定表单对象属性的错误 添加员工实验代码 表单

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

    pageEncoding="UTF-8" import="java.util.*"%>

<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>

<!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>

 

<!--

1.为什么使用SpringMVC的form标签

① 快速开发

② 表单回显

2.可以通过modelAttribute指定绑定的模型属性，

若没有指定该属性，则默认从request域中查找command的表单的bean

如果该属性也不存在，那么，则会发生错误。

 -->

 <form:form action="empAdd" method="POST" modelAttribute="employee">

         LastName : <form:input path="lastName" /><br><br>

         Email : <form:input path="email" /><br><br>

         <%

                 Map<String,String> map = new HashMap<String,String>();

                 map.put("1", "Male");

                 map.put("0","Female");

                 request.setAttribute("genders", map);

         %>

         Gender : <br><form:radiobuttons path="gender" items="${genders }" delimiter="<br>"/><br><br>

         DeptName :

                 <form:select path="department.id"

                                                 items="${deptList }"

                                                 itemLabel="departmentName"

                                                 itemValue="id"></form:select><br><br>

                 <input type="submit" value="Submit"><br><br>

 </form:form> 

</body>

</html>

控制器方法

@Controller

public class EmployeeHandler {

@RequestMapping(value="/empAdd",method=RequestMethod.POST)

public String empAdd(Employee employee){

employeeDao.save(employee);

return "redirect:/empList";

}

}

RESTRUL_CRUD_删除操作&处理静态资源

删除实验代码 页面链接

<td><a href="/empDelete/${emp.id }">Delete</a></td>

控制器方法

@RequestMapping(value="/empDelete/{id}" ,method=RequestMethod.DELETE)

public String empDelete(@PathVariable("id") Integer id){

employeeDao.delete(id);

return "redirect:/empList";

}

HiddenHttpMethodFilter过滤器

发起请求，无法执行，因为delete请求必须通过post请求转换为delete请求，借助：HiddenHttpMethodFilter过滤器 需要使用jQuery来转换请求方式 加入jQuery库文件

/scripts/jquery-1.9.1.min.js

jQuery库文件不起作用

警告: No mapping found for HTTP request with URI [/SpringMVC_03_RESTFul_CRUD/scripts/jquery-1.9.1.min.js] in DispatcherServlet with name 'springDispatcherServlet'

解决办法，SpringMVC 处理静态资源

SpringMVC 处理静态资源:

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。

解决: 在 SpringMVC 的配置文件中配置 <mvc:default-servlet-handler/>配置后，原来的请求又不好使了

需要配置<mvc:annotation-driven />

关于<mvc:default-servlet-handler/>作用

<!--

<mvc: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        

参考：CATALINA_HOME/config/web.xml

    <servlet>

        <servlet-name>default</servlet-name>

        <servlet-class>org.apache.catalina.servlets.DefaultServlet</servlet-class>

        <init-param>

            <param-name>debug</param-name>

            <param-value>0</param-value>

        </init-param>

        <init-param>

            <param-name>listings</param-name>

            <param-value>false</param-value>

        </init-param>

        <load-on-startup>1</load-on-startup>

    </servlet>

该标签属性default-servlet-name默认值是"default",可以省略。        

<mvc:default-servlet-handler/>        

 -->

<mvc:default-servlet-handler default-servlet-name="default"/>

通过jQuery转换为DELETE请求

<td><a class="delete" href="empDelete/${emp.id }">Delete</a></td>

<form action="" method="post">

<input type="hidden" name="_method" value="DELETE"/>

</form>

<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>

删除操作流程图解

RESTRUL_CRUD_修改操作

根据id查询员工对象，表单回显 页面链接

<td><a href="empEdit/${emp.id }">Edit</a></td>

控制器方法

//修改员工 - 表单回显

@RequestMapping(value="/empEdit/{id}",method=RequestMethod.GET)

public String empEdit(@PathVariable("id") Integer id,Map<String,Object> map){

map.put("employee", employeeDao.get(id));

map.put("deptList",departmentDao.getDepartments());

return "edit";

}

修改页面

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

    pageEncoding="UTF-8" import="java.util.*"%>

<%@ 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>

 

<!--

1.为什么使用SpringMVC的form标签

① 快速开发

② 表单回显

2.可以通过modelAttribute指定绑定的模型属性，

若没有指定该属性，则默认从request域中查找command的表单的bean

如果该属性也不存在，那么，则会发生错误。

修改功能需要增加绝对路径，相对路径会报错，路径不对

 -->

 <form:form action="${pageContext.request.contextPath }/empUpdate"

method="POST" modelAttribute="employee">                       

<%--

         LastName : <form:input path="lastName" /><br><br>

          --%>

                 <form:hidden path="id"/>

                 <input type="hidden" name="_method" value="PUT">

                 <%-- 这里不要使用form:hidden标签，否则会报错。

<form:hidden path="_method" value="PUT"/>

                         Spring的隐含标签，没有value属性，同时,path指定的值，在模型对象中也没有这个属性(_method)，所以回显时会报错。

                         org.springframework.beans.NotReadablePropertyException:

                         Invalid property '_method' of bean class [com.atguigu.springmvc.crud.entities.Employee]:

                         Bean property '_method' is not readable or has an invalid getter method:

                         Does the return type of the getter match the parameter type of the setter?

                  --%>

                          

         Email : <form:input path="email" /><br><br>

         <%

                 Map<String,String> map = new HashMap<String,String>();

                 map.put("1", "Male");

                 map.put("0","Female");

                 request.setAttribute("genders", map);

         %>

         Gender : <br><form:radiobuttons path="gender" items="${genders }" delimiter="<br>"/><br><br>

         DeptName :

                 <form:select path="department.id"

                                                 items="${deptList }"

                                                 itemLabel="departmentName"

                                                 itemValue="id"></form:select><br><br>

                 <input type="submit" value="Submit"><br><br>

 </form:form>

</body>

</html>

提交表单，修改数据

控制器方法

@RequestMapping(value="/empUpdate",method=RequestMethod.PUT)

public String empUpdate(Employee employee){

employeeDao.save(employee);         //用户名称不需要修改，会被置空        

return "redirect:/empList";

}

@ModelAttribute

public void getEmployee( @RequestParam(value="id",required=false) Integer id,Map<String,Object> map){

  if(id!=null){

     map.put("employee", employeeDao.get(id));

  }

}