| // Copyright 2004 The Apache Software Foundation |
| // |
| // 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.apache.tapestry.asset; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.net.URL; |
| import java.net.URLConnection; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import javax.servlet.ServletContext; |
| |
| import org.apache.tapestry.ApplicationRuntimeException; |
| import org.apache.tapestry.IComponent; |
| import org.apache.tapestry.IRequestCycle; |
| import org.apache.tapestry.Tapestry; |
| import org.apache.tapestry.engine.AbstractService; |
| import org.apache.tapestry.engine.IEngineServiceView; |
| import org.apache.tapestry.engine.ILink; |
| import org.apache.tapestry.request.ResponseOutputStream; |
| |
| /** |
| * A service for building URLs to and accessing {@link org.apache.tapestry.IAsset}s. |
| * Most of the work is deferred to the {@link org.apache.tapestry.IAsset} instance. |
| * |
| * <p>The retrieval part is directly linked to {@link PrivateAsset}. |
| * The service responds to a URL that encodes the path of a resource |
| * within the classpath. The |
| * {@link #service(IEngineServiceView, IRequestCycle, ResponseOutputStream)} |
| * method reads the resource and streams it out. |
| * |
| * <p>TBD: Security issues. Should only be able to retrieve a |
| * resource that was previously registerred in some way |
| * ... otherwise, hackers will be able to suck out the .class files |
| * of the application! |
| * |
| * @author Howard Lewis Ship |
| * @version $Id$ |
| **/ |
| |
| public class AssetService extends AbstractService |
| { |
| /** |
| * Defaults MIME types, by extension, used when the servlet container |
| * doesn't provide MIME types. ServletExec Debugger, for example, |
| * fails to do provide these. |
| * |
| **/ |
| |
| private final static Map _mimeTypes; |
| |
| static { |
| _mimeTypes = new HashMap(17); |
| _mimeTypes.put("css", "text/css"); |
| _mimeTypes.put("gif", "image/gif"); |
| _mimeTypes.put("jpg", "image/jpeg"); |
| _mimeTypes.put("jpeg", "image/jpeg"); |
| _mimeTypes.put("htm", "text/html"); |
| _mimeTypes.put("html", "text/html"); |
| } |
| |
| private static final int BUFFER_SIZE = 10240; |
| |
| /** |
| * Builds a {@link ILink} for a {@link PrivateAsset}. |
| * |
| * <p>A single parameter is expected, the resource path of the asset |
| * (which is expected to start with a leading slash). |
| * |
| **/ |
| |
| public ILink getLink(IRequestCycle cycle, IComponent component, Object[] parameters) |
| { |
| if (Tapestry.size(parameters) != 2) |
| throw new ApplicationRuntimeException( |
| Tapestry.format("service-incorrect-parameter-count", Tapestry.ASSET_SERVICE, new Integer(2))); |
| |
| // Service is stateless |
| |
| return constructLink(cycle, Tapestry.ASSET_SERVICE, null, parameters, false); |
| } |
| |
| public String getName() |
| { |
| return Tapestry.ASSET_SERVICE; |
| } |
| |
| private static String getMimeType(String path) |
| { |
| String key; |
| String result; |
| int dotx; |
| |
| dotx = path.lastIndexOf('.'); |
| key = path.substring(dotx + 1).toLowerCase(); |
| |
| result = (String) _mimeTypes.get(key); |
| |
| if (result == null) |
| result = "text/plain"; |
| |
| return result; |
| } |
| |
| /** |
| * Retrieves a resource from the classpath and returns it to the |
| * client in a binary output stream. |
| * |
| * <p>TBD: Security issues. Hackers can download .class files. |
| * |
| * |
| **/ |
| |
| public void service( |
| IEngineServiceView engine, |
| IRequestCycle cycle, |
| ResponseOutputStream output) |
| throws IOException |
| { |
| Object[] parameters = getParameters(cycle); |
| |
| if (Tapestry.size(parameters) != 2) |
| throw new ApplicationRuntimeException( |
| Tapestry.format("service-incorrect-parameter-count", Tapestry.ASSET_SERVICE, new Integer(2))); |
| |
| String resourcePath = (String) parameters[0]; |
| String checksum = (String) parameters[1]; |
| |
| URL resourceURL = engine.getResourceResolver().getResource(resourcePath); |
| |
| if (resourceURL == null) |
| throw new ApplicationRuntimeException( |
| Tapestry.format("missing-resource", resourcePath)); |
| |
| String actualChecksum = engine.getResourceChecksumSource().getChecksum(resourceURL); |
| |
| if (!actualChecksum.equals(checksum)) |
| { |
| throw new ApplicationRuntimeException( |
| Tapestry.format("AssetService.checksum-failure", checksum, resourcePath)); |
| } |
| |
| URLConnection resourceConnection = resourceURL.openConnection(); |
| |
| ServletContext servletContext = cycle.getRequestContext().getServlet().getServletContext(); |
| |
| writeAssetContent(engine, cycle, output, resourcePath, resourceConnection, servletContext); |
| } |
| |
| /** @since 2.2 **/ |
| |
| private void writeAssetContent( |
| IEngineServiceView engine, |
| IRequestCycle cycle, |
| ResponseOutputStream output, |
| String resourcePath, |
| URLConnection resourceConnection, |
| ServletContext servletContext) |
| { |
| // Getting the content type and length is very dependant |
| // on support from the application server (represented |
| // here by the servletContext). |
| |
| String contentType = servletContext.getMimeType(resourcePath); |
| int contentLength = resourceConnection.getContentLength(); |
| |
| try |
| { |
| if (contentLength > 0) |
| cycle.getRequestContext().getResponse().setContentLength(contentLength); |
| |
| // Set the content type. If the servlet container doesn't |
| // provide it, try and guess it by the extension. |
| |
| if (contentType == null || contentType.length() == 0) |
| contentType = getMimeType(resourcePath); |
| |
| output.setContentType(contentType); |
| |
| // Disable any further buffering inside the ResponseOutputStream |
| |
| output.forceFlush(); |
| |
| InputStream input = resourceConnection.getInputStream(); |
| |
| byte[] buffer = new byte[BUFFER_SIZE]; |
| |
| while (true) |
| { |
| int bytesRead = input.read(buffer); |
| |
| if (bytesRead < 0) |
| break; |
| |
| output.write(buffer, 0, bytesRead); |
| } |
| |
| input.close(); |
| } |
| catch (Throwable ex) |
| { |
| String title = Tapestry.format("AssetService.exception-report-title", resourcePath); |
| |
| engine.reportException(title, ex); |
| } |
| } |
| } |