# MatchEvaluator.java

    /*
     *  Licensed to the Apache Software Foundation (ASF) under one
     *  or more contributor license agreements.  See the NOTICE file
     *  distributed with this work for additional information
     *  regarding copyright ownership.  The ASF licenses this file
     *  to you under the Apache License, Version 2.0 (the
     *  "License"); you may not use this file except in compliance
     *  with the License.  You may obtain a copy of the License at
     *
     *   http://www.apache.org/licenses/LICENSE-2.0
     *
     *  Unless required by applicable law or agreed to in writing,
     *  software distributed under the License is distributed on an
     *   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
     *  KIND, either express or implied.  See the License for the
     *  specific language governing permissions and limitations
     *  under the License.
     */

    package org.apache.synapse.commons.evaluators;

    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.apache.synapse.commons.evaluators.source.SourceTextRetriever;

    import java.util.regex.Pattern;
    import java.util.regex.Matcher;

    /**
     * This evaluator uses regular expressions to match a given HTTP request.</p>
     *
     * <pre>
     * &lt;match type=&quot;header | param | url&quot; source=&quot;&quot; regex=&quot;&quot;/&gt;
     * </pre>
     * <p>
     * The source is used to extract the HTTP header or URL param</p>
     */
    @SuppressWarnings({"UnusedDeclaration"})
    public class MatchEvaluator implements Evaluator {

        private Log log = LogFactory.getLog(MatchEvaluator.class);

        private SourceTextRetriever textRetriever;

        private Pattern regex = null;

        public boolean evaluate(EvaluatorContext context) throws EvaluatorException {
            String sourceText = textRetriever.getSourceText(context);

            if (sourceText == null) {
                return false;
            }

            Matcher matcher = regex.matcher(sourceText);
            return matcher.matches();
        }

        public String getName() {
            return EvaluatorConstants.MATCH;
        }

        public Pattern getRegex() {
            return regex;
        }

        public void setRegex(Pattern regex) {
            this.regex = regex;
        }

        public SourceTextRetriever getTextRetriever() {
            return textRetriever;
        }

        public void setTextRetriever(SourceTextRetriever textRetriever) {
            this.textRetriever = textRetriever;
        }

        private void handleException(String message) throws EvaluatorException {
            log.error(message);
            throw new EvaluatorException(message);
        }
    }