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 */
017package org.apache.logging.log4j.core.util;
018
019import java.security.MessageDigest;
020
021import org.apache.logging.log4j.util.Strings;
022
023/**
024 *
025 */
026public 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}