Java tutorial
/* * 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.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 { StringTokenizer st = new StringTokenizer(pinnedServersValue, " ,"); 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(count.getAttributeValue())); } 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(once.getAttributeValue())) { taskDescription.setCount(1); taskDescription.setInterval(1); taskDescription.setIntervalInMs(false); } 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(repeatInterval.getAttributeValue()); 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(expr.getAttributeValue()); } } 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); } }