Java tutorial
/** * JBoss, Home of Professional Open Source * Copyright 2011, Red Hat, Inc. and individual contributors * by the @authors tag. See the copyright.txt in the distribution for a * full listing of individual contributors. * * 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.jboss.arquillian.ajocado.utils; import java.io.IOException; import java.io.InputStream; import java.io.UnsupportedEncodingException; import java.math.BigInteger; import java.net.MalformedURLException; import java.net.URL; import java.net.URLConnection; import java.nio.charset.Charset; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import org.apache.commons.codec.binary.Base64; /** * Provides URL manipulations and functionality. * * @author <a href="mailto:lfryc@redhat.com">Lukas Fryc</a> * @version $Revision$ */ public final class URLUtils { private static final int MD5_BUFFER_SIZE = 8192; private static final int HEX_RADIX = 16; private URLUtils() { } /** * Use URL context and one or more relocations to build end URL. * * @param context first URL used like a context root for all relocation changes * @param relocations array of relocation URLs * @return end url after all changes made on context with relocations * @throws AssertionError when context or some of relocations are malformed URLs */ public static URL buildUrl(String context, String... relocations) { try { return buildUrl(new URL(context), relocations); } catch (MalformedURLException e) { throw new AssertionError("URL('" + context + "') isn't valid URL"); } } /** * Use URL context and one or more relocations to build end URL. * * @param context first URL used like a context root for all relocation changes * @param relocations array of relocation URLs * @return end url after all changes made on context with relocations * @throws AssertionError when context or some of relocations are malformed URLs */ public static URL buildUrl(URL context, String... relocations) { URL url = context; for (String move : relocations) { try { url = new URL(url, move); } catch (MalformedURLException e) { throw new AssertionError("URL('" + url + "', '" + move + "') isn't valid URL"); } } return url; } /** * Gets a MD5 digest of some resource obtains as input stream from connection to URL given by URL string. * * @param url of the resource * @return MD5 message digest of resource * @throws IOException when connection to URL fails */ public static String resourceMd5Digest(String url) throws IOException { URLConnection connection = new URL(url).openConnection(); InputStream in = connection.getInputStream(); MessageDigest digest; try { digest = MessageDigest.getInstance("MD5"); } catch (NoSuchAlgorithmException ex) { throw new IllegalStateException("MD5 hashing is unsupported", ex); } byte[] buffer = new byte[MD5_BUFFER_SIZE]; int read = 0; while ((read = in.read(buffer)) > 0) { digest.update(buffer, 0, read); } byte[] md5sum = digest.digest(); BigInteger bigInt = new BigInteger(1, md5sum); return bigInt.toString(HEX_RADIX); } /** * Encodes credentials using Base64 encoding, which can be used to build a header for HTTP Basic authorization * * @param username User name to be encoded * @param password Password to be encoded * @return A string {@code username:password} encoded with Base64 */ public static String encodeBase64Credentials(String username, String password) { String credentials = username + ":" + password; try { String defaultCharsetName = Charset.defaultCharset().displayName(); byte[] credentialsAsBytes = credentials.getBytes(defaultCharsetName); byte[] encodedCredentials = Base64.encodeBase64(credentialsAsBytes); return new String(encodedCredentials, defaultCharsetName); } catch (UnsupportedEncodingException e) { throw new IllegalStateException(e); } } }