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.pig; import java.lang.reflect.Method; import java.util.List; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.DistinctCombiner; import org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner; import org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapReduce; import org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator; import org.apache.pig.classification.InterfaceAudience; import org.apache.pig.classification.InterfaceStability; import org.apache.pig.impl.PigContext; import org.apache.pig.impl.util.SpillableMemoryManager; import org.apache.pig.tools.pigstats.PigStatusReporter; @InterfaceAudience.Private @InterfaceStability.Unstable public class JVMReuseImpl { private static Log LOG = LogFactory.getLog(JVMReuseImpl.class); public void cleanupStaticData() { // Calling Pig builtin ones directly without reflection for optimization // and to reduce probability of NPE in PIG-4418 SpillableMemoryManager.staticDataCleanup(); PhysicalOperator.staticDataCleanup(); PigContext.staticDataCleanup(); PigGenericMapReduce.staticDataCleanup(); PigStatusReporter.staticDataCleanup(); PigCombiner.Combine.staticDataCleanup(); DistinctCombiner.Combine.staticDataCleanup(); String className = null; String msg = null; List<Method> staticCleanupMethods = JVMReuseManager.getInstance().getStaticDataCleanupMethods(); for (Method m : staticCleanupMethods) { try { className = m.getDeclaringClass() == null ? "anonymous" : m.getDeclaringClass().getName(); msg = "Invoking method " + m.getName() + " in class " + className + " for static data cleanup"; if (className.startsWith("org.apache.pig")) { LOG.debug(msg); } else { LOG.info(msg); } m.invoke(null); msg = null; } catch (Exception e) { LOG.error("Exception while calling static methods:" + getMethodNames(staticCleanupMethods) + ". " + msg, e); throw new RuntimeException("Error while " + msg, e); } } } private String getMethodNames(List<Method> staticCleanupMethods) { StringBuilder sb = new StringBuilder(); for (Method m : staticCleanupMethods) { if (m == null) { sb.append("null,"); } else { sb.append(m.getDeclaringClass() == null ? "anonymous" : m.getDeclaringClass().getName()); sb.append(".").append(m.getName()).append(","); } } if (sb.length() > 1) { sb.deleteCharAt(sb.length() - 1); } return sb.toString(); } }