Rest的意思就是表述性状态转移。理解就是表示被为操作资源。其实也是一种基于http结构的东西。然后应该知道这不是一种定义的规范也不是什么标准。就是一种用来表示数据以及操作服务器中资源的方法。但是Rest web的服务却又依赖于Http协议。
（1）GET方法通常用来获取某一资源或者资源集合。
（2）POST方法用于创建。
（3）PUT方法用于更新。
（4）DELETE方法用于从系统中删除资源。
工程目录：
导包：
编写web.xml文件：
<?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_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>springmvc_restful</display-name> <!--配置HiddenHttpMethodFilter--> <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> <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></web-app>entity模型：
Department：
public class Department { private Integer id; private String departmentName; public Department() { // TODO Auto-generated constructor stub } public Department(int i, String string) { this.id = i; this.departmentName = string; } 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 + "]"; } }Employee：public class Employee { private Integer id; private String lastName; private String email; //1 male, 0 female private Integer gender; private Department department; 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 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; } @Override public String toString() { return "Employee [id=" + id + ", lastName=" + lastName + ", email=" + email + ", gender=" + gender + ", department=" + department + "]"; } public Employee() { // TODO Auto-generated constructor stub }}dao层：
DepartmentDao：
@Repositorypublic 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")); } public Collection<Department> getDepartments(){ return departments.values(); } public Department getDepartment(Integer id){ return departments.get(id); } }EmployeeDao：@Repositorypublic 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, "张三", "aa@QQ.com", 1, new Department(101, "人事部"))); employees.put(1002, new Employee(1002, "李四", "bb@qq.com", 1, new Department(102, "财务部"))); employees.put(1003, new Employee(1003, "王五", "cc@qq.com", 0, new Department(103, "研发部"))); employees.put(1004, new Employee(1004, "赵六", "dd@qq.com", 0, new Department(104, "研发部"))); employees.put(1005, new Employee(1005, "田七", "ee@qq.com", 1, new Department(105, "人事部"))); } 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); }}（2）使用GET方法来查询
编写Controller：
@RequestMapping("/employeeController")@Controllerpublic class EmployeeController { @Autowired private EmployeeDao employeeDao; @RequestMapping("/showList") public String showList(Map<String,Object> map){ map.put("employees", employeeDao.getAll()); return "list"; }}编写index.jsp请求页面：<%@ 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> <a href="employeeController/showList">Show List</a></body></html>编写list.jsp接收页面：<%@ 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="${empty requestScope.employees }">没有任何员工信息</c:if> <c:if test="${!empty requestScope.employees }"> <table border="1" cellpadding="10" cellspacing="0"> <tr> <th>编号</th> <th>姓名</th> <th>邮箱</th> <th>性别</th> <th>部门</th> <th>Edit</th> <th>Delete</th> </tr> </c:if> <c:forEach items="${requestScope.employees }" var="emp"> <tr> <td>${emp.id }</td> <td>${emp.lastName }</td> <td>${emp.email }</td> <td>${emp.gender==0?'女':'男' }</td> <td>${emp.department.departmentName }</td> <td><a href="">Edit</a></td> <td><a href="">Delete</a></td> </tr> </c:forEach> </table></body></html>结果：
使用fiddler抓包结果：可以发现使用的是GET请求。
（3）使用POST方法来增加
在EmployeeController控制器中编写一个添加员工和保存员工的方法。
@RequestMapping(value="/addEmp",method=RequestMethod.GET) public String addEmp(Map<String,Object> map){ map.put("departments", departmentDao.getDepartments()); map.put("employee", new Employee()); return "input"; } @RequestMapping(value="/saveEmp",method=RequestMethod.POST) public String saveEmp(Employee employee){ employeeDao.save(employee); return "redirect:/employeeController/showList"; }编写list.jsp中添加员工的超链接<%@ 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>list</title></head><body> <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>编号</th> <th>姓名</th> <th>邮箱</th> <th>性别</th> <th>部门</th> <th>编辑</th> <th>删除</th> <th><a href="addEmp">添加员工</a></th> </tr> </c:if> <c:forEach items="${requestScope.employees }" var="emp"> <tr> <td>${emp.id }</td> <td>${emp.lastName }</td> <td>${emp.email }</td> <td>${emp.gender==0?'女':'男' }</td> <td>${emp.department.departmentName }</td> <td><a href="">Edit</a></td> <td><a href="">Delete</a></td> </tr> </c:forEach> </table></body></html>在input.jsp页面编写添加员工的表单：使用springmvc的标签<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><%@ 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>input</title></head><body> <form:form action="saveEmp" method="post" modelAttribute="employee"> 姓名：<form:input path="lastName"/><br/> 邮箱：<form:input path="email"/><br/> 性别：<form:radiobutton path="gender" label="男" value="1"/> <form:radiobutton path="gender" label="女" value="0"/><br/> 部门：<form:select path="department.id" items="${departments }" itemLabel="departmentName" itemValue="id"> </form:select><br/> <input type="submit" value="提交"/> </form:form></body></html>结果：
fiddler抓包结果：
（4）使用DELETE方法来删除
实际上使用DELETE方法来删除也是基于POST请求。
编写控制器：
@RequestMapping(value="/delete/{id}",method=RequestMethod.DELETE) public String deleteEmp(@PathVariable("id") Integer id){ employeeDao.delete(id); return "redirect:/showList"; }导入jquery-1.9.1.min.js文件，由于我们稍后要使用jquery来发送post请求。编写list.jsp文件：
<%@ 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>list</title><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"); $("form").attr("action",href).submit(); return false; }); });</script></head><body> <form action="" method="post"> <input type="hidden" name="_method" value="DELETE"/> </form> <c:if test="${empty requestScope.employees }">没有任何员工信息</c:if> <c:if test="${!empty requestScope.employees }"> <table border="1" cellpadding="10" cellspacing="0"> <tr> <th>编号</th> <th>姓名</th> <th>邮箱</th> <th>性别</th> <th>部门</th> <th>编辑</th> <th>删除</th> <th><a href="addEmp">添加员工</a></th> </tr> </c:if> <c:forEach items="${requestScope.employees }" var="emp"> <tr> <td>${emp.id }</td> <td>${emp.lastName }</td> <td>${emp.email }</td> <td>${emp.gender==0?'女':'男' }</td> <td>${emp.department.departmentName }</td> <td><a href="">修改</a></td> <td><a href="delete/${emp.id}" class="delete">删除</a></td> </tr> </c:forEach> </table></body></html>解释：由于我们需要使用超链接来发送请求，但是超链接只能发送GET请求，如果想要用超链接发送post请求，就需要使用jquery脚本来发送。问题1：为什么springmvc加载不了静态资源，就是为什么页面用不了jquery？虽然我们配置了DispatcherServlet中/方式来接收所有请求，但是restful风格却将他们当成普通请求（静态资源等）。实际上就是没有对应的解析器去解析这些资源。
解决方式：在springmvc.xml中采用<mvc:default-servlet-handler/>配置。
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。
问题2：使用了<mvc:default-servlet-handler/>标签，却使得注解@RequestMapping失效
解决方式：在springmvc.xml中采用<mvc:annotation-driven></mvc:annotation-driven>配置。
结果：赵六被删除
fiddler抓包结果：
问题3：为什么这次没有使用在Controller控制器上写@RequestMapping路径呢？解决方式：由于在Controller上添加了@RequestMapping请求类路径，则导致在使用jquery-1.9.1.min.js脚本文件时，springmvc自动就给添加了类路径，导致使用jquery文件失败。所以不采用类路径了。
（5）使用PUT方法来修改
虽然使用PUT方法来修改，但是实际上还是使用POST请求。
编写请求页面list.jsp：
<td><a href="editEmp/${emp.id}">修改</a></td>编写接收修改超链接的方法@RequestMapping(value="/editEmp/{id}",method=RequestMethod.GET)public String editEmp(@PathVariable("id") Integer id,Map<String,Object> map){ map.put("employee", employeeDao.get(id)); map.put("departments", departmentDao.getDepartments()); return "/input";}编写修改页面input.jsp：<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>input</title></head><body> <form:form action="${pageContext.request.contextPath }/saveEmp" method="POST" modelAttribute="employee"> <c:if test="${employee.id ==null }"> 姓名：<form:input path="lastName"/><br/> </c:if> <c:if test="${employee.id !=null }"> <form:hidden path="id"/> <input type="hidden" name="_method" value="PUT"/> </c:if> 邮箱：<form:input path="email"/><br/> 性别：<form:radiobutton path="gender" label="男" value="1"/> <form:radiobutton path="gender" label="女" value="0"/><br/> 部门：<form:select path="department.id" items="${departments }" itemLabel="departmentName" itemValue="id"> </form:select><br/> <input type="submit" value="提交"/> </form:form></body></html>编写接收修改页面提交数据的方法：@ModelAttributepublic void getEmp(@RequestParam(value="id",required=false) Integer id,Map<String,Object> map){ if(id !=null){ map.put("employee", employeeDao.get(id)); }} @RequestMapping(value="/saveEmp",method=RequestMethod.PUT)public String updateEmp(Employee employee){ employeeDao.save(employee); return "redirect:/showList";}至于为什么使用@ModelAttribute注解：http://blog.csdn.net/ya_1249463314/article/details/56681459#t1
回显页面还是之前的list.jsp文件。
结果：
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使用fiddler抓包：
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