springmvc 扩展实现类似于淘宝CDN 资源文件处理

1. SpringMVC XML 配置

       <!-- 简单URLaction映射 -->

<bean id="simpleUrlHandlerMapping"
class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="urlMap">
<map>
<!-- 静态资源处理器 -->
<entry key="/r/**/**">
<!-- 自己扩展的SpingMVC ResourceHttpRequestHandler 类,增加了类是与淘宝CDN通过逗号(,)隔开 
访问多个js的效果 此功能不能压缩JS 如果想实现压缩功能可通过maven 或者 ant 在编译的时候进行压缩 -->
<bean class="com.yoro.core.springmvc.ResourceHttpRequestHandler">
<property name="locations">
<list>
<!-- 只有相同目录的JS文件才能实现淘宝CDN通过逗号(,)隔开 访问多个js的效果 如 /r/ 目录下的js|css 文件 
就能实现 /r/js/ 目录下的js文件也可以有同样的效果 但 /a/css 下面的文件 和 /r/css 就不能实现 有点小遗憾,因为时间关系待以后升级 -->
<value>/r/</value>
</list>
</property>
<!-- 启用静态资源浏览器缓存一个月 -->
<!-- 通过浏览器进行的缓存 根据可浏览器实现方式不同有所差异 按刷新按扭缓存不会起 当是页面跳转或者地址栏输入则缓存会起作用 -->
<!-- 更过浏览器缓存的资料和特效 可 搜索 cachecontrol 设置   cacheSeconds 缓存时间单位是秒  2592000 表示缓存30天 因为我自己每次新版本发布都会都js css 文件增加版本号 所以缓存时间我设置的比较长 -->
<property name="cacheSeconds" value="2592000"></property>
<property name="useExpiresHeader" value="true"></property>
<property name="useCacheControlNoStore" value="true"></property>
</bean>
</entry>
<entry key="/thirdparty/**/**">
<bean class="com.yoro.core.springmvc.ResourceHttpRequestHandler">
<property name="locations">
<list>
<value>/thirdparty/</value>
</list>
</property>
<!-- 启用静态资源浏览器缓存一个月 -->
<property name="cacheSeconds" value="2592000"></property>
<property name="useExpiresHeader" value="true"></property>
<property name="useCacheControlNoStore" value="true"></property>
</bean>
</entry>
</map>
</property>
<property name="order" value="1"></property>
</bean>

 

2. 资源文件目录结构

springmvc 扩展实现类似于淘宝CDN 资源文件处理_第1张图片

3. 浏览器缓存效果


springmvc 扩展实现类似于淘宝CDN 资源文件处理_第2张图片

 4.ResourceHttpRequestHandler  扩展类代码

package com.yoro.core.springmvc;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.activation.FileTypeMap;
import javax.activation.MimetypesFileTypeMap;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.http.MediaType;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StreamUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.HttpRequestHandler;
import org.springframework.web.context.request.ServletWebRequest;
import org.springframework.web.servlet.HandlerMapping;
import org.springframework.web.servlet.support.WebContentGenerator;

public class ResourceHttpRequestHandler 
extends WebContentGenerator implements HttpRequestHandler, InitializingBean  {

	
	private static final boolean jafPresent =
			ClassUtils.isPresent("javax.activation.FileTypeMap", ResourceHttpRequestHandler.class.getClassLoader());

	private final static Log logger = LogFactory.getLog(ResourceHttpRequestHandler.class);


	private List<Resource> locations;


	public ResourceHttpRequestHandler() {
		super(METHOD_GET, METHOD_HEAD);
	}

	/**
	 * Set a {@code List} of {@code Resource} paths to use as sources
	 * for serving static resources.
	 */
	public void setLocations(List<Resource> locations) {
		Assert.notEmpty(locations, "Locations list must not be empty");
		this.locations = locations;
	}

	@Override
	public void afterPropertiesSet() throws Exception {
		if (logger.isWarnEnabled() && CollectionUtils.isEmpty(this.locations)) {
			logger.warn("Locations list is empty. No resources will be served");
		}
	}

	@Override
	public void handleRequest(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {

		checkAndPrepare(request, response, true);

		// check whether a matching resource exists
		List<Resource> resources = getResources(request);
		if (resources == null || resources.isEmpty()) {
			logger.debug("No matching resource found - returning 404");
			response.sendError(HttpServletResponse.SC_NOT_FOUND);
			return;
		}

		// check the resource's media type
		MediaType mediaType = getMediaType((String)request
				.getAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE));
		if (mediaType != null) {
			if (logger.isDebugEnabled()) {
				logger.debug("Determined media type '" + mediaType + "' for "
						+ resources.get(0));
			}
		} else {
			if (logger.isDebugEnabled()) {
				logger.debug("No media type found for " + resources.get(0)
						+ " - not sending a content-type header");
			}
		}

		for (Resource resource : resources) {
			// header phase
			if (!new ServletWebRequest(request, response)
					.checkNotModified(resource.lastModified())) {
				logger.debug("Resource not modified - returning 304");
				break;
			}
			return;
		}

		setHeaders(response, resources, mediaType);

		// content phase
		if (METHOD_HEAD.equals(request.getMethod())) {
			logger.trace("HEAD request - skipping content");
			return;
		}
		writeContent(response, resources);
	}
	
	protected MediaType getMediaType(String filename) {
		MediaType mediaType = null;
		String mimeType = getServletContext().getMimeType(filename);
		if (StringUtils.hasText(mimeType)) {
			mediaType = MediaType.parseMediaType(mimeType);
		}
		if (jafPresent && (mediaType == null || MediaType.APPLICATION_OCTET_STREAM.equals(mediaType))) {
			MediaType jafMediaType = ActivationMediaTypeFactory.getMediaType(filename);
			if (jafMediaType != null && !MediaType.APPLICATION_OCTET_STREAM.equals(jafMediaType)) {
				mediaType = jafMediaType;
			}
		}
		return mediaType;
	}

	protected void setHeaders(HttpServletResponse response,
			List<Resource> resources, MediaType mediaType) throws IOException {
		long length = 0;
		//Calculation of multiple file length
		Iterator<Resource> iter = resources.iterator();
		while (iter.hasNext()) {
			length += iter.next().contentLength();
		}
		if (length > Integer.MAX_VALUE) {
			throw new IOException(
					"Resource content too long (beyond Integer.MAX_VALUE)");
		}
		response.setContentLength((int) length);
		if (mediaType != null) {
			response.setContentType(mediaType.toString());
		}
	}

	protected void writeContent(HttpServletResponse response,
			List<Resource> resourcess) throws IOException {
		OutputStream out = response.getOutputStream();
		InputStream in = null;
		try {
			for (Resource resource : resourcess) {
				try {
					in = resource.getInputStream();
					StreamUtils.copy(in, out);
				} finally {
					try {
						in.close();
					} catch (IOException ex) {
					}
				}
			}
		} finally {
			try {
				out.close();
			} catch (IOException ex) {
			}
		}
	}

	protected List<Resource> getResources(HttpServletRequest request) {
		String path = (String) request
				.getAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);
		if (path == null) {
			throw new IllegalStateException("Required request attribute '"
					+ HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE
					+ "' is not set");
		}

		if (!StringUtils.hasText(path) || isInvalidPath(path)) {
			if (logger.isDebugEnabled()) {
				logger.debug("Ignoring invalid resource path [" + path + "]");
			}
			return null;
		}

		for (Resource location : this.locations) {
			try {
				if (logger.isDebugEnabled()) {
					logger.debug("Trying relative path [" + path
							+ "] against base location: " + location);
				}
				List<Resource> rs = new ArrayList<Resource>();
				String[] paths = path.split(",");
				for (String url : paths) {
					Resource resource = location.createRelative(url);
					if (resource.exists() && resource.isReadable()) {
						rs.add(resource);
					}
				}
				return rs;
			} catch (IOException ex) {
				logger.debug(
						"Failed to create relative resource - trying next resource location",
						ex);
			}
		}
		return null;
	}
	
	/**
	 * Validates the given path: returns {@code true} if the given path is not a valid resource path.
	 * <p>The default implementation rejects paths containing "WEB-INF" or "META-INF" as well as paths
	 * with relative paths ("../") that result in access of a parent directory.
	 * @param path the path to validate
	 * @return {@code true} if the path has been recognized as invalid, {@code false} otherwise
	 */
	protected boolean isInvalidPath(String path) {
		return (path.contains("WEB-INF") || path.contains("META-INF") || StringUtils.cleanPath(path).startsWith(".."));
	}

	/**
	 * Inner class to avoid hard-coded JAF dependency.
	 */
	private static class ActivationMediaTypeFactory {

		private static final FileTypeMap fileTypeMap;

		static {
			fileTypeMap = loadFileTypeMapFromContextSupportModule();
		}

		private static FileTypeMap loadFileTypeMapFromContextSupportModule() {
			// see if we can find the extended mime.types from the context-support module
			Resource mappingLocation = new ClassPathResource("org/springframework/mail/javamail/mime.types");
			if (mappingLocation.exists()) {
				InputStream inputStream = null;
				try {
					inputStream = mappingLocation.getInputStream();
					return new MimetypesFileTypeMap(inputStream);
				}
				catch (IOException ex) {
					// ignore
				}
				finally {
					if (inputStream != null) {
						try {
							inputStream.close();
						}
						catch (IOException ex) {
							// ignore
						}
					}
				}
			}
			return FileTypeMap.getDefaultFileTypeMap();
		}

		public static MediaType getMediaType(String filename) {
			String mediaType = fileTypeMap.getContentType(filename);
			return (StringUtils.hasText(mediaType) ? MediaType.parseMediaType(mediaType) : null);
		}
	}
}

 5.实现淘宝CDN JS 请求例子

JS例子:http://127.0.0.1/r/js/alert.js,/js/application.js,/js/bootstrap.js

CSS例子:http://127.0.1.1/r/css/activity_style.css,/css/bootstrap_responsive.css

通过逗号(,)分割他们现在就实现了通过一个请求加载多个资源文件的效果了

 

 

 

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