重寫DispatcherServlet實現動態後綴。Spring-MVC

Spring mvc已經被我們玩壞了，還能怎麼玩，像筆者這種閒着沒事還蛋疼的無聊份子。想了這麼一個花樣。

我們知道，spring默認後綴do。也可以無後綴，有些人喜歡配置action。而筆者喜歡配置啥呢，asp。php。cgi。py。或者配置個sb。當然，純粹爲了好玩。

 

思路。spring分發器，即DispatcherServlet。實質是一個servlet。什麼是servlet我就不去多說了，那麼要實現任意後綴怎麼辦呢。涼拌。真涼拌，一個servlet你怎麼實現。

然而，如果這個servlet變成了filter呢，那麼不就好辦了麼。筆者壞壞的一笑。

首先自定義一個DiyDispatcherServlet，繼承DispatcherServlet，實現Filter。

於是乎。初始化DispatcherServlet需要一個servletConfig的。而初始化Filter是一個FilterConfig

其實這兩個東西性質差不多。基本方式也差不多，是兩個接口，於是定義一個類，實現這兩個玩意，做一個轉換。

private static class ServletFilter  implements ServletConfig,FilterConfig{

		private FilterConfig filterConfig;
		
		public ServletFilter(FilterConfig filterConfig){
			this.filterConfig=filterConfig;
		}
		@Override
		public String getFilterName() {
			return filterConfig.getFilterName();
		}

		@Override
		public String getInitParameter(String s) {
			return filterConfig.getInitParameter(s);
		}

		@Override
		public Enumeration<String> getInitParameterNames() {
			return filterConfig.getInitParameterNames();
		}

		@Override
		public ServletContext getServletContext() {
			return filterConfig.getServletContext();
		}

		@Override
		public String getServletName() {
			return filterConfig.getFilterName();
		}

	}

 

來看看我們的DiyDispatcherServlet：

package com.blog.filter;

import java.io.IOException;
import java.util.Enumeration;
import java.util.List;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.DispatcherServlet;

import com.blog.comm.util.RequestUtil;
import com.blog.comm.util.SpringContextHelper;
import com.blog.service.SuffixService;

@SuppressWarnings("serial")
public class DiyDispatcherServlet extends DispatcherServlet implements Filter{

	public DiyDispatcherServlet(){
		super();
	}
	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		HttpServletRequest req=(HttpServletRequest)request;
		HttpServletResponse res=(HttpServletResponse)response;
		SuffixService suffixService=SpringContextHelper.getBean(SuffixService.class);
		List<String> suffixs=suffixService.loadSpringSuffixs();
		List<String> staList = suffixService.loadStaSuffix();
		String suffix=RequestUtil.getURLSuffix(req);
		if (staList.contains(suffix)) {
			res.setHeader("Cache-Control", "max-age=600");
			chain.doFilter(req, res);
			return;
		}
		String defSuffix = suffixService.loadSpringDefaultSuffix();
		req.setAttribute("suffix", defSuffix);
		if(suffixs.contains(suffix)){
			service(req, res);
			return;
		}
		chain.doFilter(req, res);
	}

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		super.init(new ServletFilter(filterConfig));
	}
	
	private static class ServletFilter  implements ServletConfig,FilterConfig{

		private FilterConfig filterConfig;
		
		public ServletFilter(FilterConfig filterConfig){
			this.filterConfig=filterConfig;
		}
		@Override
		public String getFilterName() {
			return filterConfig.getFilterName();
		}

		@Override
		public String getInitParameter(String s) {
			return filterConfig.getInitParameter(s);
		}

		@Override
		public Enumeration<String> getInitParameterNames() {
			return filterConfig.getInitParameterNames();
		}

		@Override
		public ServletContext getServletContext() {
			return filterConfig.getServletContext();
		}

		@Override
		public String getServletName() {
			return filterConfig.getFilterName();
		}

	}

}

那麼。List<String> suffixs=suffixService.loadSpringSuffixs();獲得後綴。如果存在後綴，就進入spring mvc去。不存在，就chain.doFilter(req, res);

 

那麼web.xml怎麼配置呢。看下面

<filter>
		<filter-name>SpringMVC</filter-name>
		<filter-class>com.blog.filter.DiyDispatcherServlet</filter-class>
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>classpath:applicationContext.xml</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>SpringMVC</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

 

 

於是乎：

 

是不是有點爽歪歪，有點羞澀啥的

 

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