Asset pipeline proposal.

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/AbstractResourceResolver.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.core.io.Resource;
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public abstract class AbstractResourceResolver implements ResourceResolver {
+
+	@Override
+	public final Resource resolve(HttpServletRequest request, String path,
+			List<Resource> locations, ResourceResolverChain chain) {
+		
+		Resource candidate = chain.next(this).resolve(request, path, locations, chain);
+		
+		return resolveInternal(request, path, locations, chain, candidate);
+	}
+	
+	protected abstract Resource resolveInternal(HttpServletRequest request, String path,
+			List<Resource> locations, ResourceResolverChain chain, Resource resolved);
+
+	@Override
+	public String resolveUrl(String resourcePath, List<Resource> locations,
+			ResourceResolverChain chain) {
+		return chain.next(this).resolveUrl(resourcePath, locations, chain);
+	}
+
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/DefaultResourceResolverChain.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.core.io.Resource;
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public class DefaultResourceResolverChain implements ResourceResolverChain{
+	
+	private static final ResourceResolver DEFAULT_RESOLVER = new PathMappingResourceResolver();
+	
+	private final List<ResourceResolver> resolvers;
+	
+	private List<ResourceTransformer> transformers = new ArrayList<ResourceTransformer>();
+	
+	public DefaultResourceResolverChain(List<ResourceResolver> resolvers, List<ResourceTransformer> transformers) {
+		this.resolvers = resolvers;
+		this.resolvers.add(DEFAULT_RESOLVER);
+		this.transformers = transformers;
+	}
+
+	@Override
+	public ResourceResolver next(ResourceResolver current) {
+		return this.resolvers.get(this.resolvers.indexOf(current) + 1);
+	}
+
+	@Override
+	public Resource resolveAndTransform(HttpServletRequest request, String path,
+			List<Resource> locations) throws IOException{
+		Resource resolved = this.resolvers.get(0).resolve(request, path, locations, this);
+		return resolved != null ? applyTransformers(request, resolved) : resolved;
+	}
+	
+	@Override
+	public String resolveUrl(String resourcePath, List<Resource> locations) {
+		return this.resolvers.get(0).resolveUrl(resourcePath, locations, this);
+	}
+	
+	protected Resource applyTransformers(HttpServletRequest request, Resource resource) throws IOException{
+		for (ResourceTransformer transformer : transformers) {
+			if (transformer.handles(request, resource)) {
+				return applyTransformers(request, transformer.transform(resource));
+			}
+		}
+		return resource;
+	}
+	
+	private static class PathMappingResourceResolver implements ResourceResolver {
+		
+		private static final Log logger = LogFactory.getLog(PathMappingResourceResolver.class);
+		
+		@Override
+		public Resource resolve(HttpServletRequest request, String path, List<Resource> locations, ResourceResolverChain chain) {
+			for (Resource location : locations) {
+				try {
+					if (logger.isDebugEnabled()) {
+						logger.debug("Trying relative path [" + path + "] against base location: " + location);
+					}
+					Resource resource = location.createRelative(path);
+					if (resource.exists() && resource.isReadable()) {
+						if (logger.isDebugEnabled()) {
+							logger.debug("Found matching resource: " + resource);
+						}
+						return resource;
+					}
+					else if (logger.isTraceEnabled()) {
+						logger.trace("Relative resource doesn't exist or isn't readable: " + resource);
+					}
+				}
+				catch (IOException ex) {
+					logger.debug("Failed to create relative resource - trying next resource location", ex);
+				}
+			}
+			return null;
+		}
+
+		@Override
+		public String resolveUrl(String resourcePath, List<Resource> locations, ResourceResolverChain chain) {
+			if (resolve(null, resourcePath, locations, chain) != null) {
+				return resourcePath;
+			}
+			return null;
+		}
+	}
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/EncodedResource.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import org.springframework.core.io.Resource;
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public interface EncodedResource extends Resource {
+
+	public String getEncoding();
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ExtensionMappingResourceResolver.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.io.File;
+import java.io.FilenameFilter;
+import java.io.IOException;
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.core.io.Resource;
+import org.springframework.util.StringUtils;
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public class ExtensionMappingResourceResolver extends AbstractResourceResolver {
+	
+	private final Log logger = LogFactory.getLog(getClass());
+	
+	private final boolean compareTimeStamp;
+	
+	public ExtensionMappingResourceResolver() {
+		this.compareTimeStamp = false;
+	}
+	
+	public ExtensionMappingResourceResolver(boolean compareTimeStamp) {
+		this.compareTimeStamp = compareTimeStamp;
+	}
+	
+	@Override
+	protected Resource resolveInternal(HttpServletRequest request, String path,
+			List<Resource> locations, ResourceResolverChain chain, Resource resolved) {
+		if (resolved != null && !compareTimeStamp) {
+			return resolved;
+		}
+		
+		for (Resource location : locations) {
+			String baseFilename = StringUtils.getFilename(path);
+			
+			try {
+				Resource basePath = location.createRelative(StringUtils.delete(path, baseFilename));
+				if (basePath.getFile().isDirectory()) {
+					for (String fileName : basePath.getFile().list(new ExtensionFilter(baseFilename))) {
+						//Always use the first match
+						Resource matched = basePath.createRelative(fileName);
+						if (resolved == null || matched.lastModified() > resolved.lastModified()) {
+							return matched;
+						} else {
+							return resolved;
+						}
+					}
+				}
+			}
+			catch (IOException e) {
+				this.logger.trace("Error occurred locating resource based on file extension mapping", e);
+			}
+			
+		}
+		return resolved;
+	}
+	
+	@Override
+	public String resolveUrl(String resourcePath, List<Resource> locations,
+			ResourceResolverChain chain) {
+		String resolved = super.resolveUrl(resourcePath, locations, chain);
+		if (StringUtils.hasText(resolved)) {
+			return resolved;
+		}
+		
+		Resource mappedResource = resolveInternal(null, resourcePath, locations, chain, null);
+		if (mappedResource != null) {
+			return resourcePath;
+		}
+		return null;
+	}
+
+
+
+	private static final class ExtensionFilter implements FilenameFilter{
+
+		private final String baseFilename;
+		private final String baseExtension;
+		private final int baseExtLen;
+		
+		
+		public ExtensionFilter(String baseFilename) {
+			this.baseFilename = baseFilename;
+			this.baseExtension = "." + StringUtils.getFilenameExtension(baseFilename);
+			this.baseExtLen = this.baseExtension.length();
+		}
+		
+		@Override
+		public boolean accept(File dir, String name) {
+			return name.contains(baseExtension) && baseFilename.equals(name.substring(0, name.lastIndexOf(baseExtension) + this.baseExtLen));  
+		}
+	}
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/FingerprintingResourceResolver.java

@@ -0,0 +1,116 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.core.io.Resource;
+import org.springframework.util.DigestUtils;
+import org.springframework.util.FileCopyUtils;
+import org.springframework.util.StringUtils;
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public class FingerprintingResourceResolver extends AbstractResourceResolver {
+
+	private final Log logger = LogFactory.getLog(getClass());
+	
+	private Pattern pattern = Pattern.compile("-(\\S*)\\.");
+	
+	@Override
+	protected Resource resolveInternal(HttpServletRequest request, String path, List<Resource> locations,
+			ResourceResolverChain chain, Resource resolved) {
+		//First try the resolved full path, in case resource has been written that way to disk at build-time
+		//or the resource is requested without fingerprint
+		if (resolved != null) {
+			return resolved;
+		}
+		
+		//Now try extracting and matching the hash for dev mode
+		String hash = extractHash(path);
+		String simplePath = !StringUtils.isEmpty(hash) ? StringUtils.delete(path, "-" + hash) : path;
+		Resource baseResource = chain.next(this).resolve(request, simplePath, locations, chain);
+		
+		if (StringUtils.isEmpty(hash) || baseResource == null) {
+			return baseResource;
+		}
+		
+		String candidateHash = calculateHash(baseResource);
+		
+		if (candidateHash.equals(hash)) {
+			this.logger.debug("Fingerprint match succeeded.");
+			return baseResource;
+		} else {
+			this.logger.debug("Potential resource found, but fingerprint doesn't match.");
+			return null;
+		}
+	}
+	
+	@Override
+	public String resolveUrl(String resourcePath, List<Resource> locations,
+			ResourceResolverChain chain) {
+		//TODO - Consider caching here for better efficiency
+		String baseUrl = chain.next(this).resolveUrl(resourcePath, locations, chain);
+		if (StringUtils.hasText(baseUrl)) {
+			Resource original = chain.next(this).resolve(null, resourcePath, locations, chain);
+			String hash = calculateHash(original);
+			return StringUtils.stripFilenameExtension(baseUrl) + "-" + hash + "." + StringUtils.getFilenameExtension(baseUrl);
+		}
+		return baseUrl;
+	}
+
+	/**
+	 * @param candidate
+	 * @return
+	 */
+	private String calculateHash(Resource resource) {
+		try {
+			byte[] content = FileCopyUtils.copyToByteArray(resource.getInputStream());
+			return DigestUtils.md5DigestAsHex(content);
+		}
+		catch (IOException e) {
+			this.logger.error("Failed to calculate hash on resource " + resource.toString());
+			return "";
+		}
+	}
+
+	/**
+	 * @param path
+	 * @return
+	 */
+	private String extractHash(String path) {
+		Matcher matcher = pattern.matcher(path);
+		if (matcher.find()) {
+			this.logger.debug("Found fingerprint in path: " + matcher.group(1));
+			String match = matcher.group(1);
+			return match.contains("-") ? match.substring(match.lastIndexOf("-") + 1) : match;
+		} else {
+			return "";
+		}
+	}
+
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/GzipResourceResolver.java

@@ -0,0 +1,135 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;
+import java.net.URL;
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.core.io.AbstractResource;
+import org.springframework.core.io.Resource;
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public class GzipResourceResolver extends AbstractResourceResolver {
+
+	private final Log logger = LogFactory.getLog(getClass());
+	
+	@Override
+	protected Resource resolveInternal(HttpServletRequest request, String path,
+			List<Resource> locations, ResourceResolverChain chain, Resource resolved) {
+		
+		if (!isGzipAccepted(request) || resolved == null) {
+			return resolved;
+		}
+		
+		try {
+			Resource gzipped = new GzippedResource(resolved);
+			if (gzipped.exists()) {
+				return gzipped;
+			}
+		} catch (IOException e) {
+			this.logger.trace("Error occurred locating gzipped resource", e);
+		}
+		return resolved;
+	}
+
+	/**
+	 * @param request 
+	 * @return
+	 */
+	private boolean isGzipAccepted(HttpServletRequest request) {
+		String val = request.getHeader("Accept-Encoding");
+		return val != null && val.toLowerCase().contains("gzip");
+	}
+	
+	private static final class GzippedResource extends AbstractResource implements EncodedResource {
+
+		private final Resource original;
+		
+		private final Resource gzipped;
+		
+		public GzippedResource(Resource original) throws IOException {
+			this.original = original;
+			this.gzipped = original.createRelative(original.getFilename()+".gz");
+		}
+
+		public InputStream getInputStream() throws IOException {
+			return gzipped.getInputStream();
+		}
+
+		public boolean exists() {
+			return gzipped.exists();
+		}
+
+		public boolean isReadable() {
+			return gzipped.isReadable();
+		}
+
+		public boolean isOpen() {
+			return gzipped.isOpen();
+		}
+
+		public URL getURL() throws IOException {
+			return gzipped.getURL();
+		}
+
+		public URI getURI() throws IOException {
+			return gzipped.getURI();
+		}
+
+		public File getFile() throws IOException {
+			return gzipped.getFile();
+		}
+
+		public long contentLength() throws IOException {
+			return gzipped.contentLength();
+		}
+
+		public long lastModified() throws IOException {
+			return gzipped.lastModified();
+		}
+
+		public Resource createRelative(String relativePath) throws IOException {
+			return gzipped.createRelative(relativePath);
+		}
+
+		public String getFilename() {
+			return original.getFilename();
+		}
+
+		public String getDescription() {
+			return gzipped.getDescription();
+		}
+
+		public String getEncoding() {
+			return "gzip";
+		}
+
+	}	
+
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/LessResourceTransformer.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.io.IOException;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.lesscss.LessCompiler;
+import org.lesscss.LessException;
+import org.springframework.core.io.Resource;
+import org.springframework.util.StringUtils;
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public class LessResourceTransformer implements ResourceTransformer {
+
+	private static final String LESS_EXT = "less";
+	
+	private final LessCompiler compiler = new LessCompiler();
+	
+	@Override
+	public Resource transform(Resource original) throws IOException {
+		TransformedResource transformed;
+		try {
+			String content = "";
+			if (original instanceof TransformedResource) {
+				content = ((TransformedResource) original).getContentAsString();
+			} else {
+				content = compiler.compile(original.getFile());
+			}
+			transformed = new TransformedResource(original.getFilename()
+				.replace("."+LESS_EXT, ""), content.getBytes("UTF-8"), original.lastModified());
+		}
+		catch (LessException le) {
+			//TODO - Nicely print out the compilation error
+			le.printStackTrace();
+			return null;
+		}
+		
+		return transformed;
+	}
+
+	@Override
+	public boolean handles(HttpServletRequest request, Resource original) {
+		return LESS_EXT.equals(StringUtils.getFilenameExtension(original.getFilename()));
+	}
+
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceHttpRequestHandler.java

@@ -18,6 +18,7 @@ package org.springframework.web.servlet.resource;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.ArrayList;
 import java.util.List;
 
 import javax.activation.FileTypeMap;
@@ -78,13 +79,32 @@ public class ResourceHttpRequestHandler extends WebContentGenerator implements H
 	private static final boolean jafPresent =
 			ClassUtils.isPresent("javax.activation.FileTypeMap", ResourceHttpRequestHandler.class.getClassLoader());
 
+	private static final String CONTENT_ENCODING = "Content-Encoding";
+
 	private List<Resource> locations;
 
-
+	private List<ResourceResolver> resourceResolvers = new ArrayList<ResourceResolver>();
+	
+	private List<ResourceTransformer> resourceTransformers = new ArrayList<ResourceTransformer>();
+	
+	private ResourceResolverChain resolverChain;
+	
 	public ResourceHttpRequestHandler() {
 		super(METHOD_GET, METHOD_HEAD);
 	}
 
+	public List<Resource> getLocations() {
+		return this.locations;
+	}
+	
+	public List<ResourceResolver> getResourceResolvers() {
+		return this.resourceResolvers;
+	}
+	
+	public List<ResourceTransformer> getResourceTransformers() {
+		return this.resourceTransformers;
+	}
+	
 	/**
 	 * Set a {@code List} of {@code Resource} paths to use as sources
 	 * for serving static resources.
@@ -93,12 +113,21 @@ public class ResourceHttpRequestHandler extends WebContentGenerator implements H
 		Assert.notEmpty(locations, "Locations list must not be empty");
 		this.locations = locations;
 	}
+	
+	public void setResourceResolvers(List<ResourceResolver> resourceResolvers) {
+		this.resourceResolvers = resourceResolvers;
+	}
+	
+	public void setResourceTransformers(List<ResourceTransformer> resourceTransformers) {
+		this.resourceTransformers = resourceTransformers;
+	}
 
 	@Override
 	public void afterPropertiesSet() throws Exception {
 		if (logger.isWarnEnabled() && CollectionUtils.isEmpty(this.locations)) {
 			logger.warn("Locations list is empty. No resources will be served");
 		}
+		this.resolverChain = new DefaultResourceResolverChain(this.resourceResolvers, this.resourceTransformers);
 	}
 
 	/**
@@ -155,7 +184,7 @@ public class ResourceHttpRequestHandler extends WebContentGenerator implements H
 		writeContent(response, resource);
 	}
 
-	protected Resource getResource(HttpServletRequest request) {
+	protected Resource getResource(HttpServletRequest request) throws IOException{
 		String path = (String) request.getAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);
 		if (path == null) {
 			throw new IllegalStateException("Required request attribute '" +
@@ -169,27 +198,7 @@ public class ResourceHttpRequestHandler extends WebContentGenerator implements H
 			return null;
 		}
 
-		for (Resource location : this.locations) {
-			try {
-				if (logger.isDebugEnabled()) {
-					logger.debug("Trying relative path [" + path + "] against base location: " + location);
-				}
-				Resource resource = location.createRelative(path);
-				if (resource.exists() && resource.isReadable()) {
-					if (logger.isDebugEnabled()) {
-						logger.debug("Found matching resource: " + resource);
-					}
-					return resource;
-				}
-				else if (logger.isTraceEnabled()) {
-					logger.trace("Relative resource doesn't exist or isn't readable: " + resource);
-				}
-			}
-			catch (IOException ex) {
-				logger.debug("Failed to create relative resource - trying next resource location", ex);
-			}
-		}
-		return null;
+		return resolverChain.resolveAndTransform(request, path, locations);
 	}
 
 	/**
@@ -241,6 +250,10 @@ public class ResourceHttpRequestHandler extends WebContentGenerator implements H
 		if (mediaType != null) {
 			response.setContentType(mediaType.toString());
 		}
+		
+		if (resource instanceof EncodedResource) {
+			response.setHeader(CONTENT_ENCODING, ((EncodedResource) resource).getEncoding());
+		}
 	}
 
 	/**
@@ -297,5 +310,5 @@ public class ResourceHttpRequestHandler extends WebContentGenerator implements H
 			return (StringUtils.hasText(mediaType) ? MediaType.parseMediaType(mediaType) : null);
 		}
 	}
-
-}
+	
+ }

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceResolver.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.core.io.Resource;
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public interface ResourceResolver {
+
+		public Resource resolve(HttpServletRequest request, String path, List<Resource> locations, ResourceResolverChain chain);
+		
+		public String resolveUrl(String resourcePath, List<Resource> locations,
+				ResourceResolverChain chain);
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceResolverChain.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.io.IOException;
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.core.io.Resource;
+
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public interface ResourceResolverChain {
+
+	public Resource resolveAndTransform(HttpServletRequest request, String path, List<Resource> locations)
+			throws IOException;
+	
+	public ResourceResolver next(ResourceResolver current);
+
+	public String resolveUrl(String resourcePath, List<Resource> locations);
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceTransformer.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.io.IOException;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.core.io.Resource;
+
+
+/**
+ * More than meets the eye.
+ * 
+ * @author Jeremy Grelle
+ */
+public interface ResourceTransformer {
+
+	public Resource transform(Resource original) throws IOException;
+	
+	public boolean handles(HttpServletRequest request, Resource original);
+	
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceUrlEncodingFilter.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.io.IOException;
+
+import javax.servlet.FilterChain;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpServletResponseWrapper;
+
+import org.springframework.web.context.WebApplicationContext;
+import org.springframework.web.context.support.WebApplicationContextUtils;
+import org.springframework.web.filter.OncePerRequestFilter;
+import org.springframework.web.util.UrlPathHelper;
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public class ResourceUrlEncodingFilter extends OncePerRequestFilter {
+
+	private ResourceUrlMapper mapper;
+
+	@Override
+	protected void doFilterInternal(HttpServletRequest request,
+			HttpServletResponse response, FilterChain filterChain)
+			throws ServletException, IOException {
+		filterChain.doFilter(request, new ResourceUrlResponseWrapper(request, response));
+	}
+	
+	@Override
+	protected void initFilterBean() throws ServletException {
+		WebApplicationContext appContext = WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
+		this.mapper = appContext.getBean(ResourceUrlMapper.class);
+	}
+
+	private class ResourceUrlResponseWrapper extends HttpServletResponseWrapper {
+		
+		private final UrlPathHelper pathHelper = new UrlPathHelper();
+		
+		private String pathPrefix;
+		
+		private ResourceUrlResponseWrapper(HttpServletRequest request, HttpServletResponse wrapped) {
+			super(wrapped);
+			
+			this.pathPrefix = pathHelper.getContextPath(request);
+			String servletPath = pathHelper.getServletPath(request);
+			String appPath = pathHelper.getPathWithinApplication(request);
+			//This accounts for the behavior when servlet is mapped to "/"
+			if (!servletPath.equals(appPath)) {
+				this.pathPrefix += pathHelper.getServletPath(request);
+			}
+		}
+
+		@Override
+		public String encodeURL(String url) {
+			if(url.startsWith(pathPrefix)) {
+				String relativeUrl = url.replaceFirst(pathPrefix, "");
+				if (!relativeUrl.startsWith("/")) {
+					relativeUrl = "/" + relativeUrl;
+				}
+				if (mapper.isResourceUrl(relativeUrl)) {
+					String resourceUrl = mapper.getUrlForResource(relativeUrl);
+					if (resourceUrl != null) {
+						return resourceUrl;
+					}
+				}
+			}
+			return super.encodeURL(url);
+		}
+
+	}
+
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceUrlMapper.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.context.ApplicationListener;
+import org.springframework.context.event.ContextRefreshedEvent;
+import org.springframework.core.OrderComparator;
+import org.springframework.util.AntPathMatcher;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.PathMatcher;
+import org.springframework.web.servlet.handler.SimpleUrlHandlerMapping;
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public class ResourceUrlMapper implements BeanPostProcessor, ApplicationListener<ContextRefreshedEvent>{
+
+	private final Map<String, ResourceHttpRequestHandler> handlers = new LinkedHashMap<String, ResourceHttpRequestHandler>();
+	
+	private final List<SimpleUrlHandlerMapping> mappings = new ArrayList<SimpleUrlHandlerMapping>();
+	
+	private final PathMatcher matcher = new AntPathMatcher();
+	
+	@Override
+	public Object postProcessBeforeInitialization(Object bean, String beanName)
+			throws BeansException {
+		return bean;
+	}
+	
+	@Override
+	public Object postProcessAfterInitialization(Object bean, String beanName)
+			throws BeansException {
+		if (ClassUtils.isAssignableValue(SimpleUrlHandlerMapping.class, bean)) {
+			SimpleUrlHandlerMapping mapping = (SimpleUrlHandlerMapping) bean;
+			for(Entry<String, ?> mappingEntry : mapping.getUrlMap().entrySet()) {
+				Object val = mappingEntry.getValue();
+				if (val instanceof ResourceHttpRequestHandler) {
+					this.mappings.add(mapping);
+				}
+			}
+		}
+		return bean;
+	}
+	
+	@Override
+	public void onApplicationEvent(ContextRefreshedEvent event) {
+		OrderComparator.sort(this.mappings);
+		for (SimpleUrlHandlerMapping mapping : mappings) {
+			for(Entry<String, ?> mappingEntry : mapping.getUrlMap().entrySet()) {
+				Object val = mappingEntry.getValue();
+				this.handlers.put(mappingEntry.getKey(), (ResourceHttpRequestHandler) val);
+			}
+		}
+	}
+	
+	public String getUrlForResource(String resourcePath) {
+		for (Entry<String, ResourceHttpRequestHandler> mapping : this.handlers.entrySet()) {
+			if (matcher.match(mapping.getKey(), resourcePath)) {
+				ResourceHttpRequestHandler handler = mapping.getValue();
+				String nestedPath = matcher.extractPathWithinPattern(mapping.getKey(), resourcePath);
+				String prefix = resourcePath.replace(nestedPath, "");
+				String url = new DefaultResourceResolverChain(handler.getResourceResolvers(), handler.
+						getResourceTransformers()).resolveUrl(nestedPath, handler.getLocations());
+				if (url != null) {
+					return prefix + url;
+				}
+			}
+		}
+		return null;
+	}
+
+	public boolean isResourceUrl(String relativeUrl) {
+		for (String mapping : this.handlers.keySet()) {
+			if (matcher.match(mapping, relativeUrl)) {
+				return true;
+			}
+		}
+		return false;
+	}
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/TransformedResource.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.resource;
+
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.util.Date;
+
+import org.springframework.core.io.ByteArrayResource;
+
+
+/**
+ * 
+ * @author Jeremy Grelle
+ */
+public class TransformedResource extends ByteArrayResource {
+
+	private final String filename;
+	private final long lastModified;
+	
+	public TransformedResource(String filename, byte[] transformedContent) {
+		super(transformedContent);
+		this.filename = filename;
+		this.lastModified = new Date().getTime();
+	}
+	
+	public TransformedResource(String filename, byte[] transformedContent, long lastModified) {
+		super(transformedContent);
+		this.filename = filename;
+		this.lastModified = lastModified;
+	}
+
+	@Override
+	public String getFilename() {
+		return this.filename;
+	}
+	
+	@Override
+	public long lastModified() throws IOException {
+		return this.lastModified;
+	}
+
+	public String getContentAsString() {
+		try {
+			return new String(getByteArray(), "UTF-8");
+		}
+		catch (UnsupportedEncodingException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+			return "";
+		}
+	}
+	
+}