javascript
SpringMVC 学习笔记(五) 基于RESTful的CRUD
1.1. 概述
当提交的表单带有_method字段时,通过HiddenHttpMethodFilter 将 POST 请求转换成 DELETE、PUT请求,加上@PathVariable注解从而实现 RESTful 风格的CRUD
1.2. 配置信息
Web.xml
<?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_3_0.xsd" version="3.0" > <!-- 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:spring-mvc.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 能够将 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>
1.3. 效果
① 通过POST 请求添加员工信息
② 通过PUT 请求改动员工信息
③ 通过DELETE 请求删除员工信息
④ 通过GET 请求 获取全部的 员工信息
1.4. 代码
Employee.java
package com.ibigsea.springmvc.model;public class Employee {private Integer id;private String name;private String email;private int sex;private Department department;public Employee(Integer id, String name, String email, int sex,Department department) {super();this.id = id;this.name = name;this.email = email;this.sex = sex;this.department = department;}public Employee() {super();}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getEmail() {return email;}public void setEmail(String email) {this.email = email;}public int getSex() {return sex;}public void setSex(int sex) {this.sex = sex;}public Department getDepartment() {return department;}public void setDepartment(Department department) {this.department = department;}@Overridepublic String toString() {return "Employee [id=" + id + ", name=" + name + ", email=" + email+ ", sex=" + sex + ", department=" + department + "]";}}Department.java
package com.ibigsea.springmvc.model;import java.io.Serializable;public class Department implements Serializable {private static final long serialVersionUID = 6881984318733090395L;private Integer id;private String name;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}@Overridepublic String toString() {return "Department [id=" + id + ", name=" + name + "]";}}RestfulController.java
package com.ibigsea.springmvc.rest;import java.util.Map;import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; 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.ibigsea.springmvc.dao.DepartmentDao; import com.ibigsea.springmvc.dao.EmployeeDao; import com.ibigsea.springmvc.model.Employee;/*** 基于Restful风格的增删改查* @author bigsea*/ @Controller @RequestMapping("/restful") public class RestfulController {@Autowiredprivate EmployeeDao employeeDao;@Autowiredprivate DepartmentDao departmentDao;/*** 由于改动的时候不能改动员工姓名,* 所以通过 @ModelAttribute 注解,* 表示在运行目标方法时,先获取该员工对象* 将员工对象存入 implicitMode 中* @param id 员工ID* @param map 实际传入的是implicitMode*/@ModelAttributepublic void getEmployee(@RequestParam(value="id",required=false) Integer id,Map<String,Object> map){if (id != null) {map.put("employee", employeeDao.getEmpById(id));}}/*** 查看全部的员工信息* @param map* @return*/@RequestMapping("/list")public String list(Map<String, Object> map){map.put("emps", employeeDao.getAll());return "list";}/*** 跳转到员工加入页面* @param map* @return*/@RequestMapping(value="/add",method=RequestMethod.GET)public String add(Map<String, Object> map){map.put("depts", departmentDao.getAll());map.put("action", "add");return "emp";}/*** 加入员工* @param emp* @return*/@RequestMapping(value="/add",method=RequestMethod.POST)public String add(Employee emp){if (emp == null) {return "emp";}if (emp.getDepartment().getId() != null) {emp.setDepartment(departmentDao.getDepartmentById(emp.getDepartment().getId()));}employeeDao.save(emp);return "redirect:/restful/list";}/*** 删除员工信息* @param id* @return*/@RequestMapping(value="/delete/{id}",method=RequestMethod.DELETE)public String delete(@PathVariable("id") Integer id){employeeDao.delEmpById(id);return "redirect:/restful/list";}/*** 由于先运行了 @ModelAttribute 注解的方法,* 获取了该员工ID所相应的员工信息* 然后在将前台获取的员工数据存入获取的员工信息中,* 这样就不用提交name属性也能够获取到值* @param emp* @return*/@RequestMapping(value="/edit",method=RequestMethod.PUT)public String edit(Employee emp){if (emp == null) {return "emp";}if (emp.getDepartment().getId() != null) {emp.setDepartment(departmentDao.getDepartmentById(emp.getDepartment().getId()));}employeeDao.save(emp);return "redirect:/restful/list";}/*** 跳转到员工改动页面* @param id 员工ID* @param map implicitMode* @return */@RequestMapping(value="/edit/{id}",method=RequestMethod.GET)public String edit(@PathVariable("id") Integer id,Map<String, Object> map){map.put("emp", employeeDao.getEmpById(id));map.put("depts", departmentDao.getAll());map.put("action", "edit");return "emp";}}EmployeeDao.java
package com.ibigsea.springmvc.dao;import java.util.Collection; import java.util.HashMap; import java.util.Map;import org.springframework.stereotype.Component;import com.ibigsea.springmvc.model.Department; import com.ibigsea.springmvc.model.Employee;@Component public class EmployeeDao {private static Map<Integer,Employee> emps = new HashMap<Integer, Employee>();/*** 初始化员工信息*/static {emps.put(1001, new Employee(1001,"AA","AA@ibigsea.com",0,new Department(101, "JAVA")));emps.put(1002, new Employee(1002,"BB","BB@ibigsea.com",0,new Department(102, ".NET")));emps.put(1003, new Employee(1003,"CC","CC@ibigsea.com",1,new Department(103, "PHP")));emps.put(1004, new Employee(1004,"DD","DD@ibigsea.com",0,new Department(104, "C")));}private static int employeeId = 1005;/*** 保存员工信息* @param emp*/public void save(Employee emp){if (emp.getId() == null) {emp.setId(employeeId++);}emps.put(emp.getId(), emp);}/*** 获取全部的员工信息* @return*/public Collection<Employee> getAll(){return emps.values();}/*** 依据ID获取员工信息* @param id* @return*/public Employee getEmpById(Integer id){return emps.get(id);}/*** 依据ID删除员工信息* @param id*/public void delEmpById(Integer id){emps.remove(id);}}DepartmentDao.java
package com.ibigsea.springmvc.dao;import java.util.Collection; import java.util.HashMap; import java.util.Map;import org.springframework.stereotype.Component;import com.ibigsea.springmvc.model.Department;@Component public class DepartmentDao {public static Map<Integer, Department> depts = new HashMap<Integer, Department>();/*** 初始化部门信息*/static {depts.put(101, new Department(101,"JAVA"));depts.put(102, new Department(102,".NET"));depts.put(103, new Department(103,"PHP"));depts.put(104, new Department(104,"C"));}/*** 获取全部的部门信息* @return*/public Collection<Department> getAll(){return depts.values();}/*** 依据ID获取部门信息* @param id* @return*/public Department getDepartmentById(Integer id){return depts.get(id);}}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"> <title>员工信息</title> </head> <body><c:if test="${ empty emps }">没有员工信息</c:if><c:if test="${ !empty emps }"><table border="1" bordercolor="black" cellspacing="0"><tr><td width="40px">id</td><td width="30px">name</td><td width="80px">email</td><td width="30px">sex</td><td width="40px">编辑</td><td width="40px">删除</td></tr><c:forEach items="${emps }" var="emp"><tr><td>${emp.id }</td><td>${emp.name }</td><td>${emp.email }</td><td>${emp.sex == 0 ? '男' : '女'}</td><td><a href="${pageContext.request.contextPath}/restful/edit/${emp.id }">Edit</a></td><td><form action="${pageContext.request.contextPath}/restful/delete/${emp.id }" method="post"><input type="hidden" name="_method" value="DELETE"><input type="submit" value="Delete"></form></td></tr></c:forEach></table></c:if><br><br><a href="${pageContext.request.contextPath}/restful/add">加入员工</a> </body> </html>Emp.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"> <title>员工信息</title> </head> <body><form action="${pageContext.request.contextPath}/restful/${action}" method="post"><c:if test="${!empty emp}"><input type="hidden" name="_method" value="PUT"><input type="hidden" name="id" value="${emp.id }"><br/><br/></c:if><c:if test="${empty emp}">name : <input type="text" name="name" value="${emp.name }"><br/><br/></c:if>email : <input type="text" name="email" value="${emp.email }"><br/><br/>sex :<input type="radio" name="sex" value="0" <c:if test="${emp.sex == 0}">checked</c:if>>男 <input type="radio" name="sex" value="1" <c:if test="${emp.sex == 1}">checked</c:if>>女<br/><br/>department :<select name="department.id"><c:forEach items="${depts }" var="dept"><option value="${dept.id }" <c:if test="${emp.department.id == dept.id}">selected</c:if>>${dept.name }</option></c:forEach></select><br><br/><input type="submit" value="提交"></form> </body> </html>1.5. 静态资源问题
由于配置了DispatcherServlet而且拦截了全部的请求,所以在加入静态资源的时候会訪问不到静态资源,在springMVC.xml配置
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，假设发现是没有经过映射的请求，就将该请求交由 WEB应用server默认的 Servlet 处理。假设不是静态资源的请求。才由DispatcherServlet 继续处理
mvc:annotation-driven
会自己主动注冊
RequestMappingHandlerMapping
RequestMappingHandlerAdapter
ExceptionHandlerExceptionResolver 三个bean。
就能訪问到静态资源了
1.6. mvc:annotation-driven和mvc:default-servlet-handler
在配置SpringMVC配置文件时加入mvc:annotation-driven
<mvc:annotation-driven /> 会自己主动注冊三个Bean
² RequestMappingHandlerMapping
² RequestMappingHandlerAdapter
² ExceptionHandlerExceptionResolver
还将提供下面支持：
– 支持使用 ConversionService 实例对表单參数进行类型转换
– 支持使用 @NumberFormat 、@DateTimeFormat注解完毕数据类型的格式化
– 支持使用 @Valid 注解对 JavaBean 实例进行 JSR 303 验证
– 支持使用 @RequestBody 和 @ResponseBody 注解
转载于:https://www.cnblogs.com/jzdwajue/p/7137280.html
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