# TaskDescriptionRepository.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.task;

    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;

    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.Map;

    /**
     * Local repository for holds Task descriptions
     */
    @SuppressWarnings({"UnusedDeclaration"})
    public class TaskDescriptionRepository {

        private static final Log log = LogFactory.getLog(TaskDescriptionRepository.class);
        private final Map<String, TaskDescription> taskDescriptionMap
                = new HashMap<String, TaskDescription>();

        /**
         * Stores a given TaskDescription
         *
         * @param taskDescription TaskDescription instance
         */
        public void addTaskDescription(TaskDescription taskDescription) {

            validateTaskDescription(taskDescription);

            String name = taskDescription.getName();
            validateName(name);
            validateUniqueness(name);

            if (log.isDebugEnabled()) {
                log.debug("Storing a TaskDescription : " + taskDescription);
            }
            taskDescriptionMap.put(name, taskDescription);

        }

        /**
         * Gets a TaskDescription
         *
         * @param name Name of the TaskDescription to be looked up
         * @return TaskDescription instance
         */
        public TaskDescription getTaskDescription(String name) {
            validateName(name);
            TaskDescription taskDescription = taskDescriptionMap.get(name);
            if (taskDescription == null) {
                if (log.isDebugEnabled()) {
                    log.debug("TaskDescription cannot be found for name :" + name +
                            " , returning null");
                }
            } else {
                if (log.isDebugEnabled()) {
                    log.debug("Returning TaskDescription : " + taskDescription);
                }
            }
            return taskDescription;
        }

        /**
         * Removing a TaskDescription
         *
         * @param name Name of the TaskDescription to be removed
         * @return Removed TaskDescription instance
         */
        public TaskDescription removeTaskDescription(String name) {
            validateName(name);
            if (log.isDebugEnabled()) {
                log.debug("Removing a TaskDescription with name : " + name);
            }
            TaskDescription taskDescription = taskDescriptionMap.remove(name);
            if (taskDescription == null) {
                if (log.isDebugEnabled()) {
                    log.debug("There is no TaskDescription to be removed with name : " + name);
                }
            } else {
                if (log.isDebugEnabled()) {
                    log.debug("Removed TaskDescription : " + taskDescription);
                }
            }
            return taskDescription;

        }

        /**
         * Return all TaskDescritions
         *
         * @return Iterator for access taskDescritions
         */
        public Iterator<TaskDescription> getAllTaskDescriptions() {
            return taskDescriptionMap.values().iterator();
        }

        /**
         * Explicit check for determine whether there is a task description with a name in interest
         *
         * @param name Name of the TaskDescription
         * @return Returns true , if there is no TaskDescription associated with given name ,
         *         otherwise , false
         */
        public boolean isUnique(String name) {
            validateName(name);
            return taskDescriptionMap.isEmpty() || !taskDescriptionMap.containsKey(name);
        }

        public void clear() {
            this.taskDescriptionMap.clear();
        }

        private void validateName(String name) {
            if (name == null || "".equals(name)) {
                throw new SynapseTaskException("Task name is null or empty", log);
            }

        }

        private void validateUniqueness(String name) {
            if (taskDescriptionMap.containsKey(name)) {
                throw new SynapseTaskException("Name with ' " + name + " ' is already there", log);
            }
        }

        private void validateTaskDescription(TaskDescription taskDescription) {
            if (taskDescription == null) {
                throw new SynapseTaskException("TaskDescription is null", log);
            }

        }
    }