SpringMVC学习笔记-REST风格CRUD

原创

umgsai 2015-03-27 14:35:43 ©著作权

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需求：在首页点击链接显示全部employee信息，点击edit和delete分别进行修改和删除操作，点击add进行添加操作。CRUD分别对应post get put delete四种请求。

目录结构如图

web.xml配置

<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    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 -->
	<!-- The front controller of this Spring Web application, responsible for handling all application requests -->
	<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>
	
	<!-- Map all requests to the DispatcherServlet for handling -->
	<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>

springmvc.xml配置

<?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:aop="http://www.springframework.org/schema/aop"
	xmlns:context="http://www.springframework.org/schema/context" 
	xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="
	http://www.springframework.org/schema/beans 
	http://www.springframework.org/schema/beans/spring-beans.xsd
	http://www.springframework.org/schema/aop
       http://www.springframework.org/schema/aop/spring-aop-4.1.xsd
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-4.1.xsd
    http://www.springframework.org/schema/tx 
    http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">

	<mvc:annotation-driven></mvc:annotation-driven>
	<!-- 配置自动扫描的包 -->
	<context:component-scan base-package="com"></context:component-scan><!-- 
	<bean id="HelloWorldController" class="com.springmvc.handlers.EmployeeHandler" /> -->
	<!-- 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 />

	<!-- 配置使用 SimpleMappingExceptionResolver 来映射异常 -->
	<bean
		class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
		<property name="exceptionAttribute" value="ex"></property>
		<property name="exceptionMappings">
			<props>
				<prop key="java.lang.ArrayIndexOutOfBoundsException">error</prop>
			</props>
		</property>
	</bean>

</beans>

Department.java

public class Department {
	private Integer id;
	private String departmentName;
	//...
}

Employee.java

public class Employee {
	private Integer id;
	private String lastName;
	private String email;
	private Integer gender;
	//1 male   0 female
	private Department department;
	//...
}

-----------------------------------------------------------------------

DepartmenDao.java

@Repository
public class DepartmenDao {
//模拟数据库操作
	private static  Map<Integer, Department> departments = null;
	static{
		departments = new HashMap<Integer, Department>();
		departments.put(1, new Department(1, "D-AA1"));
		departments.put(2, new Department(2, "D-AA2"));
		departments.put(3, new Department(3, "D-AA3"));
		departments.put(4, new Department(4, "D-AA4"));
		departments.put(5, new Department(5, "D-AA5"));
	}
	
	public Collection<Department> getDepartments(){
		return departments.values();
	}
	
	public Department getDepartment(Integer id) {
		return departments.get(id);
	}
}

EmployeeDao.java

@Repository
public class EmployeeDao {
//模拟数据库操作
	private static  Map<Integer, Employee> employees = null;
	
	@Autowired
	private DepartmenDao departmenDao;
	static{
		employees = new HashMap<Integer, Employee>();
		employees.put(1, new Employee(1, "E-AA1", "1@126.com", 0, new Department(1,"D-AA1")));
		employees.put(2, new Employee(2, "E-AA2", "2@126.com", 1, new Department(1,"D-AA1")));
		employees.put(3, new Employee(3, "E-AA3", "3@126.com", 0, new Department(2,"D-AA2")));
		employees.put(4, new Employee(4, "E-AA4", "4@126.com", 0, new Department(3,"D-AA3")));
		employees.put(5, new Employee(5, "E-AA5", "5@126.com", 1, new Department(1,"D-AA1")));
	}
	
	private static Integer initId = 1;
	public void save(Employee employee) {
		if (employee.getId() == null) {//insert or update
			employee.setId(initId++);
		}
		employee.setDepartment(departmenDao.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);
	}
}

EmployeeHandler.java 处理http请求

@Controller
public class EmployeeHandler {

	@Autowired
	private EmployeeDao employeeDao;
	@Autowired
	private DepartmenDao departmenDao;
	
	@ModelAttribute
	public void getEmployee(@RequestParam(value="id", required=false) Integer id, Map<String, Object> map) {
		if (id != null) {//修改操作
			map.put("employee", employeeDao.get(id));
		}
	}
	
	@RequestMapping("/emps")   //对应index.jsp的链接请求
	public String list(Map<String, Object>map) {
//		System.out.println(employeeDao.getAll());
		map.put("employees", employeeDao.getAll());
		return "list";//list.jsp
	}
	
	//add操作
	@RequestMapping(value="/emp", method=RequestMethod.GET)
	public String input(Map<String, Object> map) {
		map.put("departments", departmenDao.getDepartments());
		//默认要进行表单回显，所以这里要放一个employee到map里面，
		//对应input.jsp中的modelAttribute="employee"
		map.put("employee", new Employee());//input.jsp line17
		return "input";
	}
	
	@RequestMapping(value="/emp", method=RequestMethod.POST)
	public String save(Employee employee) {
		employeeDao.save(employee);
		return "redirect:/emps";
	}
	
	@RequestMapping(value="/emp/{id}", method=RequestMethod.DELETE)
	public String delete(@PathVariable("id") Integer id) {
		employeeDao.delete(id);
		return "redirect:/emps";
	}
	
	//与前面add操作的input方法不同，此处需要接收参数
	@RequestMapping(value="/emp/{id}", method=RequestMethod.GET)
	public String input(@PathVariable("id") Integer id, Map<String, Object> map) {
	        //默认要进行表单回显，所以这里要放一个employee到map里面，
		//对应input.jsp中的modelAttribute="employee"
		map.put("employee", employeeDao.get(id));
		map.put("departments", departmenDao.getDepartments());
		return "input";
	}
	
	@RequestMapping(value="/emp", method=RequestMethod.PUT)
	public String update(Employee employee) {
		employeeDao.save(employee);
		return "redirect:/emps";
	}
}

index.jsp

<a href="emps">List all employees</a><!-- 跳转到list.jsp -->

list.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!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">
<script type="text/javascript" src="js/jquery-1.9.0.min.js"></script>
<!-- 
SpringMVC处理静态资源
优雅的REST风格的资源URL不希望带.html .do等后缀
若将DispatcherServerlet请求映射配置为/，则SpringMVC将捕获web容器的所有请求，
SpringMVC会将获取js的资源请求也当做普通请求拦截，则因找不到对应处理器而发生错误。
解决办法：在SpringMVC的配置文件中配置<mvc:default-servlet-handler />
 -->
<script type="text/javascript">
	$(function() {
		$(".delete").click(function() {
			//将post请求转为delete请求
			var href = $(this).attr("href");
			$("form").attr("action", href).submit();
			return false;
		});
	})
</script>
<title>Insert title here</title>
</head>
<body>
	<form action="" method="post">
		<input type="hidden" name="_method" value="DELETE" />
	</form>
	<c:if test="${empty requestScope.employees}">
	没有员工信息
	</c:if>
	<c:if test="${!empty requestScope.employees}">
		<table border="1" cellspacing="0" cellpadding="10">
			<tr>
				<th>ID</th>
				<th>LastName</th>
				<th>Email</th>
				<th>Gender</th>
				<th>Department</th>
				<th>Edit</th>
				<th>Delete</th>
			</tr>
			<c:forEach items="${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 />
	<a href="emp">Add new emp</a>
</body>
</html>

<a href="emp">Add new emp</a> 链接到input页面

input.jsp 添加和修改公用

<%@page import="java.util.HashMap"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<%@ page import="java.util.HashMap"%>
<%@ page import="java.util.Map"%>
<%@taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!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>
	<!-- 
使用SpringMVC表单标签，可以进行表单回显
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
若该属性值也不存在，则会发生错误。
 -->
	<!-- 
 modelAttribute="employee"  与EmployeeHandler.java  line26一值。
 SpringMVC默认要进行表单回显。
  -->
	<!-- 开发的时候推荐使用绝对路径 -->
	<form:form action="${pageContext.request.contextPath }/emp"
		method="post" modelAttribute="employee">
		<!-- 不允许修改用户的LastName，当id不为空的时候即为修改操作 -->
		<c:if test="${employee.id == null}">
			<!-- path 对应html表单标签的name -->
 LastName<form:input path="lastName" />
		</c:if>
		<c:if test="${employee.id != null}">
			<form:hidden path="id" />
			<!-- 修改操作发送PUT请求，这里不能用form:hidden标签，因为modelAttribute对应的bean里没有_method属性 -->
			<input type="hidden" name="_method" value="PUT" />
		</c:if>
		<br />
 Email<form:input path="email" />
		<br />
		<%
			Map<String, String> genders = new HashMap();
				genders.put("1", "male");
				genders.put("0", "female");
				request.setAttribute("genders", genders);
		%>
 Gender<form:radiobuttons path="gender" items="${genders}"
			delimiter="<br/>" />
		<!-- delimiter换行 -->
		<br />
Department<form:select path="department.id" items="${departments}"
			itemLabel="departmentName" itemValue="id"></form:select>
		<br />
		<input type="submit" value="submit" />

	</form:form>
</body>
</html>

删除请求对应handler中的delete请求

项目源码地址 http://yunpan.cn/cZGr5gD94z3xI 访问密码 8069