    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.util;
    018
    019    import java.security.MessageDigest;
    020
    021    import org.apache.logging.log4j.util.Strings;
    022
    023    /**
    024     *
    025     */
    026    public final class NameUtil {
    027
    028        private static final int MASK = 0xff;
    029
    030        private NameUtil() {
    031        }
    032
    033        public static String getSubName(final String name) {
    034            if (name.isEmpty()) {
    035                return null;
    036            }
    037            final int i = name.lastIndexOf('.');
    038            return i > 0 ? name.substring(0, i) : Strings.EMPTY;
    039        }
    040
    041        public static String md5(final String string) {
    042            try {
    043                final MessageDigest digest = MessageDigest.getInstance("MD5");
    044                digest.update(string.getBytes());
    045                final byte[] bytes = digest.digest();
    046                final StringBuilder md5 = new StringBuilder();
    047                for (final byte b : bytes) {
    048                    final String hex = Integer.toHexString(MASK & b);
    049                    if (hex.length() == 1) {
    050                        md5.append('0');
    051                    }
    052                    md5.append(hex);
    053                }
    054                return md5.toString();
    055            } catch (final Exception ex) {
    056                return string;
    057            }
    058        }
    059    }