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.camel.util.concurrent;
018    
019    import java.util.concurrent.atomic.AtomicLong;
020    import java.util.regex.Matcher;
021    import java.util.regex.Pattern;
022    
023    import org.apache.camel.util.ObjectHelper;
024    
025    /**
026     * Various helper method for thread naming.
027     */
028    public final class ThreadHelper {
029        public static final String DEFAULT_PATTERN = "Camel Thread ##counter# - #name#";
030        private static final Pattern INVALID_PATTERN = Pattern.compile(".*#\\w+#.*");
031    
032        private static AtomicLong threadCounter = new AtomicLong();
033        
034        private ThreadHelper() {
035        }
036        
037        private static long nextThreadCounter() {
038            return threadCounter.getAndIncrement();
039        }
040    
041        /**
042         * Creates a new thread name with the given pattern
043         * <p/>
044         * See {@link org.apache.camel.spi.ExecutorServiceManager#setThreadNamePattern(String)} for supported patterns.
045         *
046         * @param pattern the pattern
047         * @param name    the name
048         * @return the thread name, which is unique
049         */
050        public static String resolveThreadName(String pattern, String name) {
051            if (pattern == null) {
052                pattern = DEFAULT_PATTERN;
053            }
054    
055            // we support #longName# and #name# as name placeholders
056            String longName = name;
057            String shortName = name.contains("?") ? ObjectHelper.before(name, "?") : name;
058            // must quote the names to have it work as literal replacement
059            shortName = Matcher.quoteReplacement(shortName);
060            longName = Matcher.quoteReplacement(longName);
061    
062            // replace tokens
063            String answer = pattern.replaceFirst("#counter#", "" + nextThreadCounter());
064            answer = answer.replaceFirst("#longName#", longName);
065            answer = answer.replaceFirst("#name#", shortName);
066    
067            // are there any #word# combos left, if so they should be considered invalid tokens
068            if (INVALID_PATTERN.matcher(answer).matches()) {
069                throw new IllegalArgumentException("Pattern is invalid: " + pattern);
070            }
071    
072            return answer;
073        }
074    
075    }