# ConfigResolver.java

    /*
     *  Copyright (c) 2024, WSO2 LLC. (https://www.wso2.com).
     *
     *  WSO2 LLC. 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.resolvers;

    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.apache.synapse.commons.property.PropertyHolder;

    /**
     * Config Resolver can be used to resolve configurable property variables in the synapse config.
     */
    public class ConfigResolver implements Resolver {

        private static final Log LOG = LogFactory.getLog(FilePropertyResolver.class);

        private String input;

        @Override
        public void setVariable(String input) {
            this.input = input;
        }

        @Override
        public String resolve() {
            String propertyValue = PropertyHolder.getInstance().getPropertyValue(this.input);
            if (propertyValue == null) {
                throw new ResolverException("Parameter key: " + input + " could not be found");
            }
            if (LOG.isDebugEnabled()) {
                LOG.debug("Resolving parameter key: "+ input + " value: " + propertyValue);
            }
            return propertyValue;
        }
    }