Java tutorial
/* * See the NOTICE file distributed with this work for additional * information regarding copyright ownership. * * This is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * This software is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */ package org.xwiki.webjars.internal; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.JarURLConnection; import java.net.URISyntaxException; import java.net.URL; import java.util.ArrayList; import java.util.Enumeration; import java.util.List; import java.util.jar.JarEntry; import java.util.jar.JarFile; import javax.inject.Inject; import javax.inject.Named; import javax.inject.Provider; import javax.inject.Singleton; import org.apache.commons.io.IOUtils; import org.apache.commons.lang3.StringUtils; import org.xwiki.component.annotation.Component; import org.xwiki.resource.ResourceReferenceSerializer; import org.xwiki.resource.SerializeResourceReferenceException; import org.xwiki.resource.UnsupportedResourceReferenceException; import org.xwiki.url.ExtendedURL; import org.xwiki.url.filesystem.FilesystemExportContext; import org.xwiki.url.internal.RelativeExtendedURL; /** * Converts a {@link WebJarsResourceReference} into a {@link ExtendedURL} (with the Context Path added) that points * to a absolute URL pointing to a file on the local filesystem. This can be used when exporting to HTML for example. * * @version $Id: 9be3c46c6dac18cef212c8259e7635ec6607d07d $ * @since 7.2M1 */ @Component @Named("filesystem") @Singleton public class FilesystemResourceReferenceSerializer implements ResourceReferenceSerializer<WebJarsResourceReference, ExtendedURL> { /** * Prefix for locating resource files (JavaScript, CSS) in the classloader. */ private static final String WEBJARS_RESOURCE_PREFIX = "META-INF/resources/webjars"; private static final String PARENT = ".."; private static final String WEBJAR_PATH = "webjars"; @Inject private Provider<FilesystemExportContext> exportContextProvider; @Override public ExtendedURL serialize(WebJarsResourceReference reference) throws SerializeResourceReferenceException, UnsupportedResourceReferenceException { // Copy the resource from the webjar to the filesystem FilesystemExportContext exportContext = this.exportContextProvider.get(); try { copyResourceFromJAR(WEBJARS_RESOURCE_PREFIX, reference.getResourceName(), WEBJAR_PATH, exportContext); } catch (IOException e) { throw new SerializeResourceReferenceException( String.format("Failed to extract and copy WebJAR resource [%s]", reference.getResourceName()), e); } List<String> pathSegments = new ArrayList<>(); // If the webjar URL is computed inside a CSS file then we need to be relative to that CSS's path, i.e only // take into account the CSS Parent levels. However if the webjar URL is not inside a CSS we need to take into // account the doc parent level. // Adjust path depending on where the current doc is stored if (exportContext.getCSSParentLevel() == 0) { for (int i = 0; i < exportContext.getDocParentLevel(); i++) { pathSegments.add(PARENT); } } else { // Adjust path for links inside CSS files (since they need to be relative to the CSS file they're in). for (int i = 0; i < exportContext.getCSSParentLevel(); i++) { pathSegments.add(PARENT); } } pathSegments.add(WEBJAR_PATH); for (String resourceSegment : StringUtils.split(reference.getResourceName(), '/')) { pathSegments.add(resourceSegment); } return new RelativeExtendedURL(pathSegments); } private File getJARFile(String resourceName) throws IOException { // Get the JAR URL by looking up the passed resource name to extract the location of the JAR URL resourceURL = Thread.currentThread().getContextClassLoader().getResource(resourceName); JarURLConnection connection = (JarURLConnection) resourceURL.openConnection(); URL jarURL = connection.getJarFileURL(); File file; try { file = new File(jarURL.toURI()); } catch (URISyntaxException e) { file = new File(jarURL.getPath()); } return file; } private void copyResourceFromJAR(String resourcePrefix, String resourceName, String targetPrefix, FilesystemExportContext exportContext) throws IOException { // Note that we cannot use ClassLoader.getResource() to access the resource since the resourcePath may point // to a directory inside the JAR, and in this case we need to copy all resources inside that directory in the // JAR! String resourcePath = String.format("%s/%s", resourcePrefix, resourceName); JarFile jar = new JarFile(getJARFile(resourcePath)); for (Enumeration<JarEntry> enumeration = jar.entries(); enumeration.hasMoreElements();) { JarEntry entry = enumeration.nextElement(); if (entry.getName().startsWith(resourcePath) && !entry.isDirectory()) { // Copy the resource! // TODO: Won't this cause collisions if the same resource is available on several subwikis for example? String targetPath = targetPrefix + entry.getName().substring(resourcePrefix.length()); File targetLocation = new File(exportContext.getExportDir(), targetPath); if (!targetLocation.exists()) { targetLocation.getParentFile().mkdirs(); FileOutputStream fos = new FileOutputStream(targetLocation); InputStream is = jar.getInputStream(entry); IOUtils.copy(is, fos); fos.close(); is.close(); } } } jar.close(); } }