Java tutorial
/*********************************************************************************************************************** * Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu) * * Licensed 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 eu.stratosphere.nephele.jobmanager; import java.lang.reflect.Constructor; import java.lang.reflect.InvocationTargetException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import eu.stratosphere.nephele.instance.InstanceManager; import eu.stratosphere.nephele.jobmanager.JobManager.ExecutionMode; import eu.stratosphere.nephele.jobmanager.scheduler.AbstractScheduler; import eu.stratosphere.util.StringUtils; /** * This class provides static utility methods for the {@link JobManager}. * */ public class JobManagerUtils { /** * The logging object used by the utility methods. */ private static final Log LOG = LogFactory.getLog(JobManagerUtils.class); /** * Private constructor. */ private JobManagerUtils() { } /** * Tries to locate a class with given name and to * instantiate a {@link AbstractScheduler} object from it. * * @param schedulerClassName * the name of the class to instantiate the scheduler object from * @param deploymentManager * the deployment manager which shall be passed on to the scheduler * @param instanceManager * the instance manager which shall be passed on to the scheduler * @return the {@link AbstractScheduler} object instantiated from the class with the provided name */ @SuppressWarnings("unchecked") static AbstractScheduler loadScheduler(final String schedulerClassName, final DeploymentManager deploymentManager, final InstanceManager instanceManager) { Class<? extends AbstractScheduler> schedulerClass; try { schedulerClass = (Class<? extends AbstractScheduler>) Class.forName(schedulerClassName); } catch (ClassNotFoundException e) { LOG.error("Cannot find class " + schedulerClassName + ": " + StringUtils.stringifyException(e)); return null; } Constructor<? extends AbstractScheduler> constructor; try { Class<?>[] constructorArgs = { DeploymentManager.class, InstanceManager.class }; constructor = schedulerClass.getConstructor(constructorArgs); } catch (NoSuchMethodException e) { LOG.error("Cannot create scheduler: " + StringUtils.stringifyException(e)); return null; } catch (SecurityException e) { LOG.error("Cannot create scheduler: " + StringUtils.stringifyException(e)); return null; } AbstractScheduler scheduler; try { scheduler = constructor.newInstance(deploymentManager, instanceManager); } catch (InstantiationException e) { LOG.error("Cannot create scheduler: " + StringUtils.stringifyException(e)); return null; } catch (IllegalAccessException e) { LOG.error("Cannot create scheduler: " + StringUtils.stringifyException(e)); return null; } catch (IllegalArgumentException e) { LOG.error("Cannot create scheduler: " + StringUtils.stringifyException(e)); return null; } catch (InvocationTargetException e) { LOG.error("Cannot create scheduler: " + StringUtils.stringifyException(e)); return null; } return scheduler; } /** * Tries to locate a class with given name and to * instantiate a instance manager from it. * * @param instanceManagerClassName * the name of the class to instantiate the instance manager object from * @return the {@link InstanceManager} object instantiated from the class with the provided name */ @SuppressWarnings("unchecked") static InstanceManager loadInstanceManager(final String instanceManagerClassName) { Class<? extends InstanceManager> instanceManagerClass; try { instanceManagerClass = (Class<? extends InstanceManager>) Class.forName(instanceManagerClassName); } catch (ClassNotFoundException e) { LOG.error("Cannot find class " + instanceManagerClassName + ": " + StringUtils.stringifyException(e)); return null; } InstanceManager instanceManager; try { instanceManager = instanceManagerClass.newInstance(); } catch (InstantiationException e) { LOG.error("Cannot create instanceManager: " + StringUtils.stringifyException(e)); return null; } catch (IllegalAccessException e) { LOG.error("Cannot create instanceManager: " + StringUtils.stringifyException(e)); return null; } return instanceManager; } /** * Tries to read the class name of the {@link AbstractScheduler} implementation from the global configuration which * is set to be used for the provided execution mode. * * @param executionMode The Nephele execution mode. * @return the class name of the {@link AbstractScheduler} implementation to be used or <code>null</code> if no * implementation is configured for the given execution mode */ static String getSchedulerClassName(ExecutionMode executionMode) { switch (executionMode) { case LOCAL: return "eu.stratosphere.nephele.jobmanager.scheduler.local.LocalScheduler"; case CLUSTER: return "eu.stratosphere.nephele.jobmanager.scheduler.queue.QueueScheduler"; default: throw new RuntimeException("Unrecognized Execution Mode."); } // String modeClass = getClassStringForMode(executionMode); // String instanceManagerClassNameKey = "jobmanager.scheduler." + modeClass + ".classname"; // String schedulerClassName = GlobalConfiguration.getString(instanceManagerClassNameKey, null); // // if (executionMode == ExecutionMode.LOCAL && schedulerClassName == null) { // schedulerClassName = ConfigConstants.DEFAULT_LOCAL_MODE_SCHEDULER; // } // return schedulerClassName; } /** * Tries to read the class name of the {@link InstanceManager} implementation from the global configuration which is * set to be used for the provided execution mode. * * @param executionMode The Nephele execution mode. * @return the class name of the {@link InstanceManager} implementation to be used or <code>null</code> if no * implementation is configured for the given execution mode */ static String getInstanceManagerClassName(ExecutionMode executionMode) { switch (executionMode) { case LOCAL: return "eu.stratosphere.nephele.instance.local.LocalInstanceManager"; case CLUSTER: return "eu.stratosphere.nephele.instance.cluster.ClusterManager"; default: throw new RuntimeException("Unrecognized Execution Mode."); } // // final String modeClass = getClassStringForMode(executionMode); // final String instanceManagerClassNameKey = "jobmanager.instancemanager." + modeClass + ".classname"; // return GlobalConfiguration.getString(instanceManagerClassNameKey, null); } }