SpringMVC学习笔记（五）

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
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    springDispatcherServlet
    
   
    org.springframework.web.servlet.DispatcherServlet
    
    
    
     contextConfigLocation
     
    
     classpath:spring-mvc.xml
     
    
   
    1
    
    
  
    
    
    
   
   
    springDispatcherServlet
    
   
    /
    
    
      
    
    
    
   
   
    hiddenHttpMethodFilter
    
   
    org.springframework.web.filter.HiddenHttpMethodFilter
    
    
      
    
   
   
    hiddenHttpMethodFilter
    
   
    /*
    
    

   
1.3. 效果
① 通过POST 请求增加员工信息
② 通过PUT 请求修改员工信息
③ 通过DELETE 请求删除员工信息
④ 通过GET 请求 获取所有的 员工信息



1.4. 代码
Employee.Java
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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
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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
[java] view plain copy
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;  
      
    /** 
     * 因为修改的时候不能修改员工姓名, 
     * 所以通过 @ModelAttribute 注解, 
     * 表示在执行目标方法时,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));  
        }  
    }  
      
    /** 
     * 查看所有的员工信息 
     * @param map 
     * @return 
     */  
    @RequestMapping("/list")  
    public String list(Map
  
    map){ map.put("emps", employeeDao.getAll()); return "list"; } /** * 跳转到员工添加页面 * @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"; } /** * 添加员工 * @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"; } /** * 因为先执行了 @ModelAttribute 注解的方法, * 获取了该员工ID所对应的员工信息 * 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属性也可以获取到值 * @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"; } /** * 跳转到员工修改页面 * @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 [java] view plain copy 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
     
       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); } /** * 获取所有的员工信息 * @return */ public Collection
       
         getAll(){ return emps.values(); } /** * 根据ID获取员工信息 * @param id * @return */ public Employee getEmpById(Integer id){ return emps.get(id); } /** * 根据ID删除员工信息 * @param id */ public void delEmpById(Integer id){ emps.remove(id); } } DepartmentDao.java [java] view plain copy 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
        
          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")); } /** * 获取所有的部门信息 * @return */ public Collection
          
            getAll(){ return depts.values(); } /** * 根据ID获取部门信息 * @param id * @return */ public Department getDepartmentById(Integer id){ return depts.get(id); } } List.jsp [html] view plain copy <%@ 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 
               
                
 
                  
                  
                
  
                
             
             
            
           

           
 
           添加员工   Emp.jsp [html] view plain copy <%@ 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 因为配置了DispatcherServlet并且拦截了所有的请求,所以在添加静态资源的时候会访问不到静态资源,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，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 mvc:annotation-driven 会自动注册 RequestMappingHandlerMapping RequestMappingHandlerAdapter ExceptionHandlerExceptionResolver 三个bean。 就能访问到静态资源了 1.6. mvc:annotation-driven和mvc:default-servlet-handler 在配置SpringMVC配置文件时添加mvc:annotation-driven  会自动注册三个Bean ² RequestMappingHandlerMapping ² RequestMappingHandlerAdapter ² ExceptionHandlerExceptionResolver 还将提供以下支持： – 支持使用 ConversionService 实例对表单参数进行类型转换 – 支持使用 @NumberFormat 、@DateTimeFormat注解完成数据类型的格式化 – 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