001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements. See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache license, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License. You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the license for the specific language governing permissions and
015     * limitations under the license.
016     */
017    package org.apache.logging.log4j.core.helpers;
018    
019    import java.security.MessageDigest;
020    
021    /**
022     *
023     */
024    public final class NameUtil {
025    
026        private static final int MASK = 0xff;
027    
028        private NameUtil() {
029        }
030    
031        public static String getSubName(final String name) {
032            if (name.length() == 0) {
033                return null;
034            }
035            final int i = name.lastIndexOf('.');
036            return i > 0 ? name.substring(0, i) : "";
037        }
038    
039        public static String md5(final String string) {
040            try {
041                final MessageDigest digest = MessageDigest.getInstance("MD5");
042                digest.update(string.getBytes());
043                final byte[] bytes = digest.digest();
044                final StringBuilder md5 = new StringBuilder();
045                for (final byte b : bytes) {
046                    final String hex = Integer.toHexString(MASK & b);
047                    if (hex.length() == 1) {
048                        md5.append('0');
049                    }
050                    md5.append(hex);
051                }
052                return md5.toString();
053            } catch (final Exception ex) {
054                return string;
055            }
056        }
057    }