SSM框架整合-restful风格

Restful 风格是什么

大家在做Web开发的过程中，method常用的值是get和post. 可事实上，method值还可以是put和delete等等其他值。

既然method值如此丰富，那么就可以考虑使用同一个url，但是约定不同的method来实施不同的业务，这就是Restful的基本考虑。

CRUD是最常见的操作，在使用Restful 风格之前，通常的增加做法是这样的：

/addCategory?name=xxx

可是使用了Restuful风格之后，增加就变成了：

/category

CRUD如下表所示，URL就都使用一样的 "/category"，区别只是在于method不同，服务器根据method的不同来判断浏览器期望做的业务行为

传统风格	Restful风格
	url	method	url	method
增加	/addCategory?name=xxx	POST	/category	PUT
删除	/deleteCategory?id=123	GET	/category/123	DELETE
修改	/updateCategory?id=123&name=yyy	POST	/category/123	POST
获取	/getCategory?id=123	GET	/category/123	GET
查询	/listCategory	GET	/category	GET

web.xml

SpringMVC 只能处理post和get,为了还原对put和delete的处理，web.xml里面要加如下过滤器

<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>

<?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"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">

<!-- spring的配置文件-->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<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>

<filter>
<filter-name>CharacterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CharacterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!-- spring mvc核心：分发servlet -->
<servlet>
<servlet-name>mvc-dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- spring mvc的配置文件 -->
<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>mvc-dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>

</web-app>

4.listCategory.jsp

listCategory.jsp 做了如下修改

1. 增加

1.1 action修改为"category"

1.2 增加如下filed, 虽然这个form的method是post, 但是springmvc看到这个_method的值是put后，会把其修改为put.

<input type="hidden" name="_method" value="PUT">

2. 删除

2.1 url修改为category/id

2.2 点击超链后，会使用form提交，并且提交_method的值为delete,以达到和增加类似的效果

$(function(){
$(".delete").click(function(){
var href=$(this).attr("href");
$("#formdelete").attr("action",href).submit();
return false;
})
})

3. 获取

3.1 url修改为了/category/id

4. 在最开始增加了jquery.min.js的引入

<script type="text/javascript" src="js/jquery.min.js"></script>

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8" import="java.util.*"%>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

<script type="text/javascript" src="js/jquery.min.js"></script>

<script type="text/javascript">
/*将post method 改变为delete*/
$(function(){
$(".delete").click(function(){
var href=$(this).attr("href");
$("#formdelete").attr("action",href).submit();
return false;
})
})
</script>

<div style="width:500px;margin:0px auto;text-align:center">
<table align='center' border='1' cellspacing='0'>
<tr>
<td>id</td>
<td>name</td>
<td>编辑</td>
<td>删除</td>
</tr>
<c:forEach items="${cs}" var="c" varStatus="st">
<tr>
<td>${c.id}</td>
<td>${c.name}</td>
<td><a href="category/${c.id}">编辑</a></td>
<td><a class="delete" href="category/${c.id}">删除</a></td>
</tr>
</c:forEach>
</table>
<div style="text-align:center">
<a href="?start=0">首  页</a>
<a href="?start=${page.start-page.count}">上一页</a>
<a href="?start=${page.start+page.count}">下一页</a>
<a href="?start=${page.last}">末  页</a>
</div>

<div style="text-align:center;margin-top:40px">

<form method="post" action="category">

<input type="hidden" name="_method" value="PUT">
分类名称： <input name="name" value="" type="text"> <br><br>
<input type="submit" value="增加分类">
</form>

</div>
</div>

<form id="formdelete" action="" method="POST" >
<input type="hidden" name="_method" value="DELETE">
</form>

5.editCategory.jsp

action修改为了 category/id

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8" import="java.util.*"%>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

<div style="width:500px;margin:0px auto;text-align:center">
<div style="text-align:center;margin-top:40px">
<form method="post" action="../category/${c.id}">
分类名称： <input name="name" value="${c.name}" type="text"> <br><br>
<input type="submit" value="修改分类">
</form>

</div>
</div>

6.CategoryController

CRUD的RequestMapping都修改为了/category,只是method各不相同。 

其他的。。。没变化

package com.how2java.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import com.how2java.pojo.Category;
import com.how2java.service.CategoryService;
import com.how2java.util.Page;

// 告诉spring mvc这是一个控制器类
@Controller
@RequestMapping("")
public class CategoryController {
@Autowired
CategoryService categoryService;

@RequestMapping(value="/category",method=RequestMethod.GET)
public ModelAndView listCategory(Page page){

ModelAndView mav = new ModelAndView();
List<Category> cs= categoryService.list(page);
int total = categoryService.total();

ce28

page.caculateLast(total);

// 放入转发参数
mav.addObject("cs", cs);
// 放入jsp路径
mav.setViewName("listCategory");
return mav;
}

@RequestMapping(value="/category",method=RequestMethod.PUT)
public ModelAndView addCategory(Category category){
System.out.println("category.getName():"+category.getName());
categoryService.add(category);
ModelAndView mav = new ModelAndView("redirect:/category");
return mav;
}

@RequestMapping(value="/category/{id}",method=RequestMethod.DELETE)
public ModelAndView deleteCategory(Category category){
categoryService.delete(category);
ModelAndView mav = new ModelAndView("redirect:/category");
return mav;
}
@RequestMapping(value="/category/{id}",method=RequestMethod.GET)
public ModelAndView editCategory(Category category){
Category c= categoryService.get(category.getId());
ModelAndView mav = new ModelAndView("editCategory");
mav.addObject("c", c);
return mav;
}
@RequestMapping(value="/category/{id}",method=RequestMethod.POST)
public ModelAndView updateCategory(Category category){
categoryService.update(category);
ModelAndView mav = new ModelAndView("redirect:/category");
return mav;
}

}