SpringMVC - RESTful SpringMVC CRUD
SpringMVC - 5
- RESTful SpringMVC CRUD
-
- demo需求
- 涉及到的一些操作
-
- 1. 处理静态资源
- demo实现
-
- 1. SpringMVC配置文件
- 2. web.xml配置文件
- 3. Employee和Department类
- 4. EmployeeDao和DepartmentDao
- 5. jsp页面编写
-
- 1. index.jsp
- 2. list.jsp
- 3. input.jsp
- 6. EmployeeHandler
RESTful SpringMVC CRUD
demo需求
- 显示所有员工信息
- URI：emps
- 请求方式：GET
- 请求效果
ID LastName Email Gender Department Edit Delete 1001 AA [email protected] Male AA EditDelete1002 CC [email protected] Female CC EditDelete1003 BB [email protected] Male BB EditDelete1004 EE [email protected] Male EE EditDelete1005 DD [email protected] Female DD EditDelete
- 添加所有员工信息
- 显示添加页面：
- URI：emp
- 请求方式：GET
- 显示效果
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- 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
ID LastName Email Gender Department Edit Delete 1001 AA [email protected] Male AA EditDelete1002 CC [email protected] Female CC EditDelete1003 BB [email protected] Male BB EditDelete1004 EE [email protected] Male EE EditDelete1005 DD [email protected] Female DD EditDelete1006 FF [email protected] Male FF EditDelete
- 显示添加页面：
- 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。[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-yuQho02G-1611913301542)(en-resource://database/680:1)]
- 显示修改页面：
- 相关的类：
- 实体类：Employee、Department
Employee Department id id lastName departmentName email gender - Handler：EmployeeHandler
- Dao：EmployeeDao、DepartmentDao
- 实体类：Employee、Department
- 相关的页面
- list.jsp
- input.jsp
- edit.jsp
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涉及到的一些操作
1. 处理静态资源
- 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SpringMVC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 - 可以在SpringMVC的配置文件中配置
- 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
demo实现
1. SpringMVC配置文件
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
<context:component-scan base-package="com.luckyazrael.springmvc.crud">context:component-scan>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/">property>
<property name="suffix" value=".jsp">property>
bean>
<mvc:default-servlet-handler/>
<mvc:annotation-driven>mvc:annotation-driven>
beans>
2. web.xml配置文件
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<servlet>
<servlet-name>springDispatchServletservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:springmvc.xmlparam-value>
init-param>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>springDispatchServletservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
<filter>
<filter-name>HiddenHttpMethodFilterfilter-name>
<filter-class>org.springframework.web.filter.HiddenHttpMethodFilterfilter-class>
filter>
<filter-mapping>
<filter-name>HiddenHttpMethodFilterfilter-name>
<url-pattern>/*url-pattern>
filter-mapping>
web-app>
3. Employee和Department类
见上方表格
4. EmployeeDao和DepartmentDao
省略了与数据库交互的内容，重点不在数据库操作，so…从简
@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","[email protected]",1,new Department(101,"D-AA")));
employees.put(1002,new Employee(1002,"E-BB","[email protected]",1,new Department(102,"D-BB")));
employees.put(1003,new Employee(1003,"E-CC","[email protected]",0,new Department(103,"D-CC")));
employees.put(1004,new Employee(1004,"E-DD","[email protected]",0,new Department(104,"D-DD")));
employees.put(1005,new Employee(1005,"E-EE","[email protected]",1,new Department(105,"D-EE")));
}
/**
* 若新增员工，该员工的id为initId
*/
private static Integer initId = 1006;
/**
* 新增员工信息
* @param employee
*/
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（查询）所有员工信息
* @return
*/
public Collection<Employee> getAll(){
return employees.values();
}
/**
* 根据员工id获取（查询）员工的信息
* @param id
* @return
*/
public Employee get(Integer id){
return employees.get(id);
}
/**
* 根据员工id删除员工信息
* @param id
*/
public void delete(Integer id){
employees.remove(id);
}
}
@Repository
public class DepartmentDao {
private static Map<Integer, Department> departments = null;
static {
departments = new HashMap<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"));
}
/**
* 获取全部的Departments
* @return
*/
public Collection<Department> getDepartments(){
return departments.values();
}
/**
* 根据id获取对应的Department
* @param id
* @return
*/
public Department getDepartment(Integer id){
return departments.get(id);
}
}
5. jsp页面编写
1. index.jsp
<body>
<a href="emps">List All Employeesa>
body>
2. list.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>listtitle>
<%--
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SpringMVC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/>
--%>
<script type="text/javascript" src="script/jquery-1.7.2.js">script>
<script type="text/javascript">
$(function () {
$(".delete").click(function () {
var href = $(this).attr("href")
$("form").attr("action",href).submit();
return false;
});
})
script>
head>
<body>
<form action="" method="post">
<input type="hidden" name="_method" value="DELETE"/>
form>
<c:if test="${empty requestScope.employees }">
没有任何员工信息。
c:if>
<c:if test="${!empty requestScope.employees }">
<table border="1" cellpadding="10" cellspacing="0">
<tr>
<th>IDth>
<th>LastNameth>
<th>Emailth>
<th>Genderth>
<th>Departmentth>
<th>Editth>
<th>Deleteth>
tr>
<c:forEach items="${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}">Edita> td>
<td><a class="delete" href="emp/${emp.id}">Deletea>td>
tr>
c:forEach>
table>
c:if>
<br><br>
<a href="emp">Add New Employeea>
body>
html>
3. input.jsp
使用Spring的表单标签
- 通过SpringMVC的表单标签可以实现将模型数据中的属性和HTML表单元素相绑定，以实现表单数据更便捷编辑和表单值的回显
form标签
- 一般情况下，通过GET请求获取表单页面，而通过POST请求提交表单页面，因此获取表单页面和提交表单页面的URL是相同的。只要满足该最佳条件的契约，form:form 标签就无需通过action属性指定表单提交的URL
- 可以通过modelAttribute属性指定绑定的模型属性，若没有指定该属性，则默认从request域对象中读取command的表单bean，如果该属性值夜幕存在，则会发生错误。
表单标签
- SpringMVC提供了多个表单组件标签，如
- path：表单字段，对应html元素的name属性，支持级联属性
- htmlEscape：是否对表单值的HTML特殊字符进行转换，默认为true
- cssClass：表单组件对应的CSS样式类名
- cssErrorClass：表单组件的数据存在错误时，采取的CSS样式
form:input、form:password、form:hidden、form:textarea：对应HTML表单的text、password、hidden、textarea标签form:radiobutton：单选框组件标签，当表单bean对应的属性值和value值相等时，单选框被选中form:radiobuttons：单选框组标签，用于构造多个单选框- items：可以使一个List、String[]或Map
- itemvalue：指定radio的value值。可以是集合中bean的一个属性值
- itemLabel：指定radio的label值
- delimiter：多个单选框可以通过delimiter指定分隔符
form:checkbox：复选框组件。用于构造单个复选框form:checkboxs：用于构造多个复选框。使用方法同form:radiobuttons标签form:select：用于构造下拉框组件。使用方法同form:radiobuttons标签form:option：下拉框选项组件标签。使用方法同form:radiobuttons标签form:errors：显示表单组件或数据校验所对应的错误
<%@ page import="java.util.Map" %>
<%@ page import="java.util.HashMap" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>inputtitle>
head>
<body>
<%--
1. 为什么要使用SpringMVC的form标签？
可以更快速的开发出表单页面，而且可以更方便的进行表单值的回显
2. 注意：可以通过 modelAttribute 属性指定绑定的模型属性，
若没有指定该属性，则默认从request域对象中读取command的表单bean，
如果该属性值也不存在，则会发生错误。
--%>
<form:form action="${pageContext.request.contextPath}/emp" method="POST" modelAttribute="employee">
<%-- path属性对应html 表单标签中的name属性值 --%>
<c:if test="${employee.id == null}">
LastName:<form:input path="lastName" />
c:if>
<c:if test="${employee.id != null}">
<form:hidden path="id"/>
<%--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" --%>
<input type="hidden" name="_method" value="PUT"/>
c:if>
<br>
Email:<form:input path="email" /> <br>
<%
Map<String,String> genders = new HashMap<>();
genders.put("0","Female");
genders.put("1","Male");
request.setAttribute("genders",genders);
%>
Gender:<form:radiobuttons path="gender" items="${genders}"/> <br>
Department:<form:select path="department.id" items="${departments}" itemLabel="departmentName" itemValue="id"/><br>
<input type="submit" value="Submit"/>
form:form>
body>
html>
6. EmployeeHandler
@Controller
public class EmployeeHandler {
@Autowired
private EmployeeDao employeeDao;
@Autowired
private DepartmentDao departmentDao;
@ModelAttribute
public void getEmployee(@RequestParam(value = "id",required = false) Integer id,Map<String,Object> map){
if (id != null){
map.put("employee",employeeDao.get(id));
}
}
@RequestMapping(value = "/emp",method = RequestMethod.PUT)
public String update(Employee employee){
employeeDao.save(employee);
return "redirect:/emps";
}
@RequestMapping(value = "/emp/{id}",method = RequestMethod.GET)
public String input(@PathVariable("id") Integer id,Map<String,Object> map){
map.put("employee",employeeDao.get(id));
map.put("departments",departmentDao.getDepartments());
return "input";
}
/**
* 执行删除的操作
* @param id
* @return
*/
@RequestMapping(value = "/emp/{id}",method = RequestMethod.DELETE)
public String delete(@PathVariable("id") Integer id){
employeeDao.delete(id);
return "redirect:/emps";
}
/**
* 执行添加操作并重定向到list页面
* @param employee
* @return
*/
@RequestMapping(value = "/emp",method = RequestMethod.POST)
public String save(Employee employee){
employeeDao.save(employee);
return "redirect:/emps";
}
/**
* 跳转到添加员工信息的操作页面
* @param map
* @return
*/
@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";
}
/**
* 跳转到list页面，并显示所有的员工信息
* @param map
* @return
*/
@RequestMapping("/emps")
public String list(Map<String,Object> map){
map.put("employees",employeeDao.getAll());
return "list";
}
}