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.rendering.internal.macro.script; import java.io.UnsupportedEncodingException; import java.net.URI; import java.net.URISyntaxException; import java.net.URL; import java.net.URLEncoder; import java.net.URLStreamHandlerFactory; import java.util.LinkedHashSet; import java.util.Set; import java.util.StringTokenizer; import javax.inject.Inject; import javax.inject.Named; import javax.inject.Singleton; import org.apache.commons.lang3.StringUtils; import org.xwiki.classloader.ExtendedURLClassLoader; import org.xwiki.classloader.ExtendedURLStreamHandler; import org.xwiki.classloader.URIClassLoader; import org.xwiki.component.annotation.Component; /** * Supports the following syntax for JARs attached to wiki pages: * {@code attach:(wiki):(space).(page)@(attachment)}. * * @version $Id: f804a9f874195224b698dd7404cf3dcc570f1b00 $ * @since 2.0.1 */ @Component @Singleton public class DefaultAttachmentClassLoaderFactory implements AttachmentClassLoaderFactory { /** * The prefix to specify a JAR attached to a wiki page. This is because we also support {@code http://} prefixes * to load JARs from remote locations. */ private static final String ATTACHMENT_PREFIX = "attach:"; /** * The Stream handler factory to use in the created classloader in order to be able to load our custom * {@code attachmentjar} custom protocol. */ @Inject private URLStreamHandlerFactory streamHandlerFactory; /** * The stream handler for our custom {@code attachmentjar} protocol. We use it to get access to the protocol * name and to transform from URI to URL. */ @Inject @Named("attachmentjar") private ExtendedURLStreamHandler attachmentJarHander; /** * {@inheritDoc} * @see AttachmentClassLoaderFactory#createAttachmentClassLoader(String, ClassLoader) */ public ExtendedURLClassLoader createAttachmentClassLoader(String jarURLs, ClassLoader parent) throws Exception { URI[] uris = extractURIs(jarURLs).toArray(new URI[0]); return new URIClassLoader(uris, parent, this.streamHandlerFactory); } /** * {@inheritDoc} * @see AttachmentClassLoaderFactory#extendAttachmentClassLoader(String, ExtendedURLClassLoader) */ public void extendAttachmentClassLoader(String jarURLs, ExtendedURLClassLoader source) throws Exception { for (URI uri : extractURIs(jarURLs)) { if (uri.getScheme().equalsIgnoreCase(this.attachmentJarHander.getProtocol())) { source.addURL(new URL(null, uri.toString(), this.streamHandlerFactory.createURLStreamHandler(uri.getScheme()))); } else { source.addURL(uri.toURL()); } } } /** * @param jarURLs the comma-separated list of JARs locations, specified using either an already registered * protocol (such as {@code http}) or using the format {@code attach:(wiki):(space).(page)@(filename)}. * @return the list of URIs * @throws URISyntaxException in case of an invalid URI */ private Set<URI> extractURIs(String jarURLs) throws URISyntaxException { // Parse the passed JAR URLs to tokenize it. Set<URI> uris = new LinkedHashSet<URI>(); if (StringUtils.isNotEmpty(jarURLs)) { StringTokenizer tokenizer = new StringTokenizer(jarURLs, ","); while (tokenizer.hasMoreElements()) { String token = tokenizer.nextToken().trim(); if (token.startsWith(ATTACHMENT_PREFIX)) { uris.add(createURI(token)); } else { uris.add(new URI(token)); } } } return uris; } /** * @param attachmentReference the attachment reference in the form {@code attach:(wiki):(space).(page)@(filename)} * @return a URI of the form {@code attachmentjar://(wiki):(space).(page)@(filename)}. * The {@code (wiki):(space).(page)@(filename)} part is URL-encoded * @throws URISyntaxException in case of an invalid URI */ private URI createURI(String attachmentReference) throws URISyntaxException { String uriBody = attachmentReference.substring(ATTACHMENT_PREFIX.length()); try { // Note: we encode using UTF8 since it's the W3C recommendation. // See http://www.w3.org/TR/html40/appendix/notes.html#non-ascii-chars // TODO: Once the xwiki-url module is usable, refactor this code to use it and remove the need to // perform explicit encoding here. uriBody = URLEncoder.encode(uriBody, "UTF-8"); } catch (UnsupportedEncodingException e) { // Not supporting UTF-8 as a valid encoding for some reasons. We consider XWiki cannot work // without that encoding. throw new RuntimeException("Failed to URL encode [" + uriBody + "] using UTF-8.", e); } return new URI(this.attachmentJarHander.getProtocol() + "://" + uriBody); } }