# PropertyHolder.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.property;

    import java.util.concurrent.ConcurrentHashMap;

    /**
     * Property Holder is the class used to store the properties in the map
     */
    public class PropertyHolder {

        private ConcurrentHashMap<String, String> properties;

        private static class PropertyLoaderHelper {
            private static final PropertyHolder INSTANCE = new PropertyHolder();
        }

        private PropertyHolder() {}

        public static PropertyHolder getInstance() {
            return PropertyLoaderHelper.INSTANCE;
        }

        public void setProperty(String key, String value) {
            getProperties().put(key, value);
        }

        public String getPropertyValue(String key) {
            return getProperties().get(key);
        }

        public Boolean hasKey(String key) {
            return getProperties().containsKey(key);
        }

        public ConcurrentHashMap<String, String> getProperties() {
            if (properties == null) {
                this.properties = new ConcurrentHashMap<>();
            }
            return this.properties;
        }
    }