spring 3.0 应用springmvc 构造RESTful URL 详细讲解

在线springmvc_rest demo

由于下一版本的rapid-framwork需要集成spring RESTful URL,所以研究了一下怎么搭建. 并碰到了一下问题。

springmvc 3.0 中增加 RESTful URL功能，构造出类似javaeye现在的URL。 rest介绍 , 这里还有struts2 rest构造的一篇文章: 使用 Struts 2 开发 RESTful 服务

简单例子如下,比如如下URL

/blog/1  HTTP GET =>    得到id = 1的blog

/blog/1  HTTP DELETE => 删除 id = 1的blog

/blog/1  HTTP PUT  =>   更新id = 1的blog

/blog     HTTP POST =>   新增BLOG

以下详细解一下spring rest使用.

首先，我们带着如下 三 个问题 查看本文。
1. 如何在java构造没有扩展名的RESTful url,如 /forms/1,而不是 /forms/1.do

2. 由于我们要构造没有扩展名的url本来是处理静态资源的容器映射的，现在被我们的spring占用了，冲突怎么解决?
3. 浏览器的form标签不支持提交delete,put请求，如何曲线解决?

springmvc rest 实现

springmvc的resturl是通过@RequestMapping 及@PathVariable annotation提供的,通过如@RequestMapping(value="/blog/{id}",method=RequestMethod.DELETE)即可处理/blog/1 的delete请求.

@RequestMapping(value="/blog/{id}",method=RequestMethod.DELETE)

public ModelAndView delete(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) {

	blogManager.removeById(id);

	return new ModelAndView(LIST_ACTION);

}

@RequestMapping @PathVariable如果URL中带参数，则配合使用，如

@RequestMapping(value="/blog/{blogId}/message/{msgId}",method=RequestMethod.DELETE)

public ModelAndView delete(@PathVariable("blogId") Long blogId,@PathVariable("msgId") Long msgId,HttpServletRequest request,HttpServletResponse response) {

}

spring rest配置指南

1. springmvc web.xml配置

	<!-- 该servlet为tomcat,jetty等容器提供,将静态资源映射从/改为/static/目录，如原来访问 http://localhost/foo.css ,现在http://localhost/static/foo.css -->

	<servlet-mapping>

		<servlet-name>default</servlet-name>

		<url-pattern>/static/*</url-pattern>

	</servlet-mapping>

	<servlet>

	    <servlet-name>springmvc</servlet-name>

	    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

	    <load-on-startup>1</load-on-startup>

	</servlet>

	<!-- URL重写filter,用于将访问静态资源http://localhost/foo.css 转为http://localhost/static/foo.css -->

	<filter>

		<filter-name>UrlRewriteFilter</filter-name>

		<filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class>

		<init-param>

		    	<param-name>confReloadCheckInterval</param-name>

		    	<param-value>60</param-value>

    		</init-param>

		<init-param>

            		<param-name>logLevel</param-name>

            		<param-value>DEBUG</param-value>

        	</init-param>

	</filter>

	<filter-mapping>

		<filter-name>UrlRewriteFilter</filter-name>

		<url-pattern>/*</url-pattern>

	</filter-mapping>

	<!-- 覆盖default servlet的/, springmvc servlet将处理原来处理静态资源的映射 -->

	<servlet-mapping>

	    <servlet-name>springmvc</servlet-name>

	    <url-pattern>/</url-pattern>

	</servlet-mapping>

	<!-- 浏览器不支持put,delete等method,由该filter将/blog?_method=delete转换为标准的http delete方法 -->

	<filter>

		<filter-name>HiddenHttpMethodFilter</filter-name>

		<filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>

	</filter>

	<filter-mapping>

		<filter-name>HiddenHttpMethodFilter</filter-name>

		<servlet-name>springmvc</servlet-name>

	</filter-mapping>

2. webapp/WEB-INF/springmvc-servlet.xml配置,使用如下两个class激活@RequestMapping annotation

    <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"/>

    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>

完整配置

<beans default-autowire="byName"   >

	<!-- 自动搜索@Controller标注的类 -->

	<context:component-scan base-package="com.**.controller"/>

    <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"/>

    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>

    <!-- Default ViewResolver -->

    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">

        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>

        <property name="prefix" value="/pages"/>

        <property name="suffix" value=".jsp"></property>

    </bean>

    <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource" p:basename="i18n/messages"/>

    <!-- Mapping exception to the handler view -->

    <bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">

    	<!-- to /commons/error.jsp -->

        <property name="defaultErrorView" value="/commons/error"/>

        <property name="exceptionMappings">

            <props>

            </props>

        </property>

    </bean>

</beans>

3. Controller编写

/**

 * @RequestMapping("/userinfo") 具有层次关系，方法级的将在类一级@RequestMapping之一,

 * 如下面示例, 访问方法级别的@RequestMapping("/new"),则URL为 /userinfo/new

 */

@Controller

@RequestMapping("/userinfo")

public class UserInfoController extends BaseSpringController{

	//默认多列排序,example: username desc,createTime asc

	protected static final String DEFAULT_SORT_COLUMNS = null; 

	private UserInfoManager userInfoManager;

	private final String LIST_ACTION = "redirect:/userinfo";

	/**

	 * 通过spring自动注入

	 **/

	public void setUserInfoManager(UserInfoManager manager) {

		this.userInfoManager = manager;

	}

	/** 列表 */

	@RequestMapping

	public ModelAndView index(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) {

		PageRequest<Map> pageRequest = newPageRequest(request,DEFAULT_SORT_COLUMNS);

		//pageRequest.getFilters(); //add custom filters

		Page page = this.userInfoManager.findByPageRequest(pageRequest);

		savePage(page,pageRequest,request);

		return new ModelAndView("/userinfo/list","userInfo",userInfo);

	}

	/** 进入新增 */

	@RequestMapping(value="/new")

	public ModelAndView _new(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) throws Exception {

		return new ModelAndView("/userinfo/new","userInfo",userInfo);

	}

	/** 显示 */

	@RequestMapping(value="/{id}")

	public ModelAndView show(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {

		UserInfo userInfo = (UserInfo)userInfoManager.getById(id);

		return new ModelAndView("/userinfo/show","userInfo",userInfo);

	}

	/** 编辑 */

	@RequestMapping(value="/{id}/edit")

	public ModelAndView edit(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {

		UserInfo userInfo = (UserInfo)userInfoManager.getById(id);

		return new ModelAndView("/userinfo/edit","userInfo",userInfo);

	}

	/** 保存新增 */

	@RequestMapping(method=RequestMethod.POST)

	public ModelAndView create(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) throws Exception {

		userInfoManager.save(userInfo);

		return new ModelAndView(LIST_ACTION);

	}

	/** 保存更新 */

	@RequestMapping(value="/{id}",method=RequestMethod.PUT)

	public ModelAndView update(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {

		UserInfo userInfo = (UserInfo)userInfoManager.getById(id);

		bind(request,userInfo);

		userInfoManager.update(userInfo);

		return new ModelAndView(LIST_ACTION);

	}

	/** 删除 */

	@RequestMapping(value="/{id}",method=RequestMethod.DELETE)

	public ModelAndView delete(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) {

		userInfoManager.removeById(id);

		return new ModelAndView(LIST_ACTION);

	}

	/** 批量删除 */

	@RequestMapping(method=RequestMethod.DELETE)

	public ModelAndView batchDelete(@RequestParam("items") Long[] items,HttpServletRequest request,HttpServletResponse response) {

		for(int i = 0; i < items.length; i++) {

			userInfoManager.removeById(items[i]);

		}

		return new ModelAndView(LIST_ACTION);

	}

}

上面是rapid-framework新版本生成器生成的代码,以后也将应用此规则,rest url中增删改查等基本方法与Controller的方法映射规则

	/userinfo 			=> index()

	/userinfo/new		=> _new()

	/userinfo/{id}		=> show()

	/userinfo/{id}/edit 		=> edit()

	/userinfo 	POST		=> create()

	/userinfo/{id} 	PUT	=> update()

	/userinfo/{id} 	DELETE	=> delete()

	/userinfo 	DELETE		=> batchDelete()

注(不使用 /userinfo/add  => add() 方法是由于add这个方法会被maxthon浏览器当做广告链接过滤掉,因为包含ad字符)

4. jsp 编写

<form:form action="${ctx}/userinfo/${userInfo.userId}" method="put">

</form:form>

生成的html内容如下, 生成一个hidden的_method=put,并于web.xml中的HiddenHttpMethodFilter配合使用，在服务端将post请求改为put请求

<form id="userInfo" action="/springmvc_rest_demo/userinfo/2" method="post">

	<input type="hidden" name="_method" value="put"/>

</form>

另外一种方法是你可以使用ajax发送put,delete请求.

5. 静态资源的URL重写

如上我们描述，现因为将default servlet映射至/static/的子目录，现我们访问静态资源将会带一个/static/前缀.

如 /foo.gif, 现在访问该文件将是 /static/foo.gif.
那如何避免这个前缀呢，那就是应用URL rewrite,现我们使用 http://tuckey.org/urlrewrite/, 重写规则如下

<urlrewrite>

    <!-- 访问jsp及jspx将不rewrite url,其它.js,.css,.gif等将重写,如 /foo.gif => /static/foo.gif -->

    <rule>

    	<condition operator="notequal" next="and" type="request-uri">.*.jsp</condition>

    	<condition operator="notequal" next="and" type="request-uri">.*.jspx</condition>

        <from>^(/.*\..*)$</from>

        <to>/static$1</to>

    </rule>

</urlrewrite>

另笔者专门写了一个 RestUrlRewriteFilter来做同样的事件，以后会随着rapid-framework一起发布. 比这个更加轻量级.

并且该代码已经贡献给spring,不知会不会在下一版本发布

在线DEMO地址 : http://demo.rapid-framework.org.cn:8080/springmvc_rest_demo/userinfo