ingo@100: /*
ingo@100:  * Copyright (c) 2010 by Intevation GmbH
ingo@100:  *
ingo@100:  * This program is free software under the LGPL (>=v2.1)
ingo@100:  * Read the file LGPL.txt coming with the software for details
ingo@100:  * or visit http://www.gnu.org/licenses/ if it does not exist.
ingo@100:  */
ingo@100: 
ingo@79: package de.intevation.artifactdatabase;
ingo@79: 
ingo@79: import java.io.UnsupportedEncodingException;
ingo@79: 
ingo@79: import java.util.UUID;
ingo@79: 
ingo@80: import org.apache.commons.codec.DecoderException;
ingo@80: 
ingo@80: import org.apache.commons.codec.binary.Hex;
ingo@80: 
ingo@79: import org.apache.log4j.Logger;
ingo@79: 
ingo@79: /**
sascha@87:  * Commonly used string functions.
sascha@87:  *
ingo@79:  * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a>
ingo@79:  */
ingo@79: public final class StringUtils
ingo@79: {
ingo@79:     private static Logger logger = Logger.getLogger(StringUtils.class);
ingo@79: 
sascha@87:     /**
sascha@87:      * Generated a random UUIDv4 in form of a string.
sascha@87:      * @return the UUID
sascha@87:      */
ingo@79:     public static final String newUUID() {
ingo@79:         return UUID.randomUUID().toString();
ingo@79:     }
ingo@79: 
sascha@87:     /**
sascha@87:      * Checks if a given string is a valid UUID.
sascha@87:      * @param uuid The string to test.
sascha@87:      * @return true if the string is a valid UUID else false.
sascha@87:      */
ingo@79:     public static final boolean checkUUID(String uuid) {
ingo@79:         try {
ingo@79:             UUID.fromString(uuid);
ingo@79:         }
ingo@79:         catch (IllegalArgumentException iae) {
ingo@79:             logger.warn(iae.getLocalizedMessage());
ingo@79:             return false;
ingo@79:         }
ingo@79:         return true;
ingo@79:     }
ingo@79: 
sascha@87:     /**
sascha@87:      * Returns the UTF-8 byte array representation of a given string.
sascha@87:      * @param s The string to be transformed.
sascha@87:      * @return The byte array representation.
sascha@87:      */
ingo@79:     public static final byte [] getUTF8Bytes(String s) {
ingo@79:         try {
ingo@79:             return s.getBytes("UTF-8");
ingo@79:         }
ingo@79:         catch (UnsupportedEncodingException usee) {
ingo@79:             logger.error(usee.getLocalizedMessage(), usee);
ingo@79:             return s.getBytes();
ingo@79:         }
ingo@79:     }
ingo@80: 
sascha@87:     /**
sascha@87:      * Tries to convert a Base64 encoded string into the
sascha@87:      * corresponing byte array.
sascha@87:      * @param s The Base64 encoded string
sascha@87:      * @return The byte array representation or null if
sascha@87:      * an decoding error occurs.
sascha@87:      */
ingo@80:     public static final byte [] decodeHex(String s) {
ingo@80:         try {
ingo@80:             return Hex.decodeHex(s.toCharArray());
ingo@80:         }
ingo@80:         catch (DecoderException de) {
ingo@80:             return null;
ingo@80:         }
ingo@80:     }
sascha@231: 
sascha@231:     public static final String repeat(String s, int count, String sep) {
sascha@231:         if (count <= 0) {
sascha@231:             return "";
sascha@231:         }
sascha@231:         StringBuilder sb = new StringBuilder(s);
sascha@237:         for (--count; count > 0; --count) {
sascha@231:             sb.append(sep).append(s);
sascha@231:         }
sascha@231:         return sb.toString();
sascha@231:     }
sascha@231: 
sascha@231:     public static final String repeat(char c, int count, char sep) {
sascha@231:         if (count <= 0) {
sascha@231:             return "";
sascha@231:         }
sascha@231:         StringBuilder sb = new StringBuilder(2*count-1).append(c);
sascha@237:         for (--count; count > 0; --count) {
sascha@231:             sb.append(sep).append(c);
sascha@231:         }
sascha@231:         return sb.toString();
sascha@231:     }
ingo@79: }
ingo@79: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :