# TaskDescriptionFactory.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.axiom.om.OMAttribute;
    import org.apache.axiom.om.OMElement;
    import org.apache.axiom.om.OMNamespace;
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.apache.synapse.commons.resolvers.ResolverFactory;
    import org.apache.synapse.commons.util.PropertyHelper;

    import javax.xml.namespace.QName;
    import java.util.ArrayList;
    import java.util.Iterator;
    import java.util.List;
    import java.util.StringTokenizer;

    /**
     * Create TaskDescription based on OMElement
     */
    public class TaskDescriptionFactory {

        private static final Log log = LogFactory.getLog(TaskDescriptionFactory.class);
        private static final String NULL_NAMESPACE = "";
        private final static String TASK = "task";
        private final static String TRIGGER = "trigger";
        private final static String PROPERTY = "property";
        private static final String DESCRIPTION = "description";

        public static TaskDescription createTaskDescription(OMElement el, OMNamespace tagetNamespace) {

            if (log.isDebugEnabled()) {
                log.debug("Creating SimpleQuartz Task");
            }
            QName task = createQName(TASK, tagetNamespace);
            if (task.equals(el.getQName())) {

                TaskDescription taskDescription = new TaskDescription();

                String name = el.getAttributeValue(
                        new QName(NULL_NAMESPACE, "name"));
                if (name != null) {
                    taskDescription.setName(name);
                } else {
                    handleException("Name for a task is required, missing name in the task");
                }

                String group = el.getAttributeValue(
                        new QName(NULL_NAMESPACE, "group"));
                if (group != null) {
                    taskDescription.setTaskGroup(group);
                }

                // set the task class
                OMAttribute classAttr = el.getAttribute(new QName("class"));
                if (classAttr != null && classAttr.getAttributeValue() != null) {
                    String classname = classAttr.getAttributeValue();
                    try {
                        Class.forName(classname).newInstance();
                    } catch (Exception e) {
                        handleException("Failed to load task class " + classname, e);
                    }
                    taskDescription.setTaskImplClassName(classname);
                } else {
                    log.warn("TaskClass cannot be found." +
                            "Task implementation may need a task class if there is no default one");
                }

                OMElement descElem = el.getFirstChildWithName(createQName(DESCRIPTION, tagetNamespace));
                if (descElem != null) {
                    taskDescription.setTaskDescription(descElem.getText());
                }

                // set pinned server list
                OMAttribute pinnedServers = el.getAttribute(new QName(NULL_NAMESPACE, "pinnedServers"));
                if (pinnedServers != null) {
                    String pinnedServersValue = pinnedServers.getAttributeValue();
                    if (pinnedServersValue == null) {
                        // default to all servers
                    } else {
                        String  resolvedPinnedServersValue =
                                ResolverFactory.getInstance().getResolver(pinnedServersValue).resolve();
                        StringTokenizer st = new StringTokenizer(resolvedPinnedServersValue, " ,");
                        List<String> pinnedServersList = new ArrayList<String>();
                        while (st.hasMoreTokens()) {
                            String token = st.nextToken();
                            if (token.length() != 0) {
                                pinnedServersList.add(token);
                            }
                        }
                        taskDescription.setPinnedServers(pinnedServersList);
                    }
                }

                // next sort out the property children

                Iterator it = el.getChildrenWithName(createQName(PROPERTY, tagetNamespace));
                while (it.hasNext()) {
                    OMElement prop = (OMElement) it.next();
                    if (PropertyHelper.isStaticProperty(prop)) {
                        taskDescription.setXmlProperty(prop);
                    } else {
                        handleException("Tasks does not support dynamic properties");
                    }
                }

                // setting the trigger to the task
                OMElement trigger = el.getFirstChildWithName(createQName(TRIGGER, tagetNamespace));
                if (trigger != null) {

                    OMAttribute count = trigger.getAttribute(new QName("count"));
                    if (count != null) {
                        try {
                            taskDescription.setCount(Integer.parseInt(ResolverFactory.getInstance().
                                    getResolver(count.getAttributeValue()).resolve()));
                        } catch (Exception e) {
                            handleException("Failed to parse trigger count as an integer", e);
                        }
                    }

                    OMAttribute once = trigger.getAttribute(new QName("once"));
                    if (once != null && Boolean.TRUE.toString().equals(ResolverFactory.getInstance().
                            getResolver(once.getAttributeValue()).resolve())) {
                        taskDescription.setCount(1);
                        taskDescription.setInterval(1000);
                        taskDescription.setIntervalInMs(true);
                    }

                    OMAttribute repeatInterval = trigger.getAttribute(new QName("interval"));
                    if (repeatInterval == null && taskDescription.getCount() > 1) {
                        handleException("Trigger seems to be " +
                                "a simple trigger, but no interval specified");
                    } else if (repeatInterval != null && repeatInterval.getAttributeValue() != null) {
                        try {
                            long repeatIntervalInSeconds = Long.parseLong(
                                    ResolverFactory.getInstance().
                                            getResolver(repeatInterval.getAttributeValue()).resolve());
                            long repeatIntervalInMillis = repeatIntervalInSeconds * 1000;
                            taskDescription.setInterval(repeatIntervalInMillis);
                            taskDescription.setIntervalInMs(true);
                        } catch (Exception e) {
                            handleException("Failed to parse trigger interval as a long value", e);
                        }
                    }

                    OMAttribute expr = trigger.getAttribute(new QName("cron"));
                    if (expr == null && taskDescription.getInterval() == 0) {
                        taskDescription.setCount(1);
                        taskDescription.setInterval(1);
                        taskDescription.setIntervalInMs(false);
                    } else if (expr != null && taskDescription.getInterval() > 0) {
                        handleException("Trigger syntax error : " +
                                "both cron and simple trigger attributes are present");
                    } else if (expr != null && expr.getAttributeValue() != null) {
                        taskDescription.setCronExpression(ResolverFactory.getInstance().
                                getResolver(expr.getAttributeValue()).resolve());
                    }

                } else {
                    taskDescription.setCount(1);
                    taskDescription.setInterval(1);
                    taskDescription.setIntervalInMs(false);
                }

                return taskDescription;
            } else {
                handleException("Syntax error in the task : wrong QName for the task");
                return null;
            }
        }

        private static QName createQName(String localName, OMNamespace omNamespace) {
            return new QName(omNamespace.getNamespaceURI(), localName, omNamespace.getPrefix());
        }

        private static void handleException(String message, Exception e) {
            log.error(message);
            throw new SynapseTaskException(message, e);
        }

        private static void handleException(String message) {
            log.error(message);
            throw new SynapseTaskException(message);
        }

    }