# NotFactory.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.config;

    import org.apache.synapse.commons.evaluators.Evaluator;
    import org.apache.synapse.commons.evaluators.EvaluatorException;
    import org.apache.synapse.commons.evaluators.NotEvaluator;
    import org.apache.axiom.om.OMElement;
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;

    /**
     * This Factory creates a {@link NotEvaluator} from the following XML configuration.</p>
     *
     * <pre>
     * &lt;not&gt;
     *     one evaluator
     * &lt;/not&gt;
     * </pre>
     */
    public class NotFactory implements EvaluatorFactory {
        private Log log = LogFactory.getLog(NotFactory.class);

        public Evaluator create(OMElement e) throws EvaluatorException {
            NotEvaluator not = new NotEvaluator();

            OMElement ce = e.getFirstElement();

            EvaluatorFactory ef = EvaluatorFactoryFinder.getInstance().
                    findEvaluatorFactory(ce.getLocalName());

            if (ef == null) {
                handleException("Invalid configuration element: " + ce.getLocalName());
                return null;
            }

            Evaluator evaluator = ef.create(ce);

            not.setEvaluator(evaluator);

            return not;
        }

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