    001    // Copyright 2011 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    //     http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.internal.services;
    016
    017    import org.apache.tapestry5.services.StackTraceElementAnalyzer;
    018
    019    import java.util.regex.Pattern;
    020
    021    /**
    022     * Uses a regular expression to identify which CSS class to apply to a frame. The frame's {@code toString()} is used. Uses
    023     * {@link java.util.regex.Matcher#find()} to search for a subsequence of the frame's description.
    024     *
    025     * @since 5.3
    026     */
    027    public class RegexpStackTraceElementAnalyzer implements StackTraceElementAnalyzer
    028    {
    029        private final Pattern pattern;
    030
    031        private final String cssClass;
    032
    033        public RegexpStackTraceElementAnalyzer(Pattern pattern, String cssClass)
    034        {
    035            this.pattern = pattern;
    036            this.cssClass = cssClass;
    037        }
    038
    039        public String classForFrame(StackTraceElement frame)
    040        {
    041            if (pattern.matcher(frame.toString()).find())
    042            {
    043                return cssClass;
    044            }
    045
    046            return null;
    047        }
    048    }