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