# ParameterTextRetriever.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.source;

    import org.apache.synapse.commons.evaluators.EvaluatorContext;
    import org.apache.synapse.commons.evaluators.EvaluatorException;
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;

    import java.io.UnsupportedEncodingException;

    public class ParameterTextRetriever implements SourceTextRetriever {

        private static final Log log = LogFactory.getLog(ParameterTextRetriever.class);

        private String source;

        public ParameterTextRetriever(String source) {
            this.source = source;
        }

        public String getSourceText(EvaluatorContext context) throws EvaluatorException {
            try {
                return context.getParam(source);
            } catch (UnsupportedEncodingException e) {
                String message = "Error retrieving paramter: " + source;
                log.error(message);
                throw new EvaluatorException(message);
            }
        }

        public String getSource() {
            return source;
        }
    }