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;	}	@Override	public 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;	}	@Override	public 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 {		@Autowired	private EmployeeDao employeeDao;		@Autowired	private 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	 */	@ModelAttribute	public void getEmployee(@RequestParam(value="id",required=false) Integer id,Map
     
       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
      
        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
       
         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
        
          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;@Componentpublic class EmployeeDao {		private static Map
     
       emps = new HashMap
      
       ();		/**	 * 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
       
         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;@Componentpublic class DepartmentDao {	public static Map
     
       depts = new HashMap
      
       ();		/**	 * 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
       
         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" %>
     	
     
      		没有员工信息	
         
         		
      		    		
      
      
    			       
        
    				         
id
    				         
name
    				         
email
    				         
sex
    				         
编辑
    				         
删除
    			        
		    	        
		    			         
${emp.id }
		    			         
${emp.name }
		    			         
${emp.email }
		    			         
${emp.sex == 0 ? '男' : '女'}
		    			         
Edit
		    			         
          
 
            
            
          
		    			
		    		        
		    	    		       
      
    
         
    加入员工

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" %>
     	
     
		
      			
       			
       
       
       
		
      		
      
       name : 
       
       
       
      		email : 
      
      
      
		sex :
      
      
       checked
      >男    		
      
      
       checked
      >女
      
      
		department :
      							selected>${dept.name }							
      
      
		
      	
     

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