core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/impl/ExecutorFactoryImpl.java

   1 /*-
   2  * ============LICENSE_START=======================================================
   3  *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
   4  * ================================================================================
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *      http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  *
  17  * SPDX-License-Identifier: Apache-2.0
  18  * ============LICENSE_END=========================================================
  19  */
  20
  21 package org.onap.policy.apex.core.engine.executor.impl;
  22
  23 import java.util.Map;
  24 import java.util.Map.Entry;
  25 import java.util.TreeMap;
  26
  27 import org.onap.policy.apex.core.engine.EngineParameterConstants;
  28 import org.onap.policy.apex.core.engine.EngineParameters;
  29 import org.onap.policy.apex.core.engine.ExecutorParameters;
  30 import org.onap.policy.apex.core.engine.context.ApexInternalContext;
  31 import org.onap.policy.apex.core.engine.executor.Executor;
  32 import org.onap.policy.apex.core.engine.executor.ExecutorFactory;
  33 import org.onap.policy.apex.core.engine.executor.StateFinalizerExecutor;
  34 import org.onap.policy.apex.core.engine.executor.TaskExecutor;
  35 import org.onap.policy.apex.core.engine.executor.TaskSelectExecutor;
  36 import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
  37 import org.onap.policy.apex.core.engine.executor.exception.StateMachineRuntimeException;
  38 import org.onap.policy.apex.model.policymodel.concepts.AxState;
  39 import org.onap.policy.apex.model.policymodel.concepts.AxStateFinalizerLogic;
  40 import org.onap.policy.apex.model.policymodel.concepts.AxTask;
  41 import org.onap.policy.apex.model.utilities.Assertions;
  42 import org.onap.policy.common.parameters.ParameterService;
  43 import org.slf4j.ext.XLogger;
  44 import org.slf4j.ext.XLoggerFactory;
  45
  46 /**
  47  * The Class ExecutorFactoryImpl is a factory class that returns task selection logic and task logic executors depending
  48  * on the type of logic executor has been specified for the task selection logic in a state or task logic in a task.
  49  *
  50  * @author Liam Fallon (liam.fallon@ericsson.com)
  51  */
  52 public class ExecutorFactoryImpl implements ExecutorFactory {
  53     // Get a reference to the logger
  54     private static final XLogger LOGGER = XLoggerFactory.getXLogger(ExecutorFactoryImpl.class);
  55
  56     // A map of logic flavours mapped to executor classes for plugins to executors for those logic flavours
  57     private Map<String, Class<Executor<?, ?, ?, ?>>> taskExecutorPluginClassMap = new TreeMap<>();
  58     private Map<String, Class<Executor<?, ?, ?, ?>>> taskSelectionExecutorPluginClassMap = new TreeMap<>();
  59     private Map<String, Class<Executor<?, ?, ?, ?>>> stateFinalizerExecutorPluginClassMap = new TreeMap<>();
  60
  61     // A map of parameters for executors
  62     private final Map<String, ExecutorParameters> implementationParameterMap = new TreeMap<>();
  63
  64     /**
  65      * Constructor, builds the class map for executors.
  66      *
  67      * @throws StateMachineException on plugin creation errors
  68      */
  69     public ExecutorFactoryImpl() throws StateMachineException {
  70         final EngineParameters engineParameters = ParameterService.get(EngineParameterConstants.MAIN_GROUP_NAME);
  71
  72         Assertions.argumentOfClassNotNull(engineParameters, StateMachineException.class,
  73                         "Parameter \"engineParameters\" may not be null");
  74
  75         // Instantiate each executor class map entry
  76         for (final Entry<String, ExecutorParameters> executorParameterEntry : engineParameters.getExecutorParameterMap()
  77                         .entrySet()) {
  78             // Get classes for all types of executors for this logic type
  79             taskExecutorPluginClassMap.put(executorParameterEntry.getKey(),
  80                             getExecutorPluginClass(executorParameterEntry.getValue().getTaskExecutorPluginClass()));
  81             taskSelectionExecutorPluginClassMap.put(executorParameterEntry.getKey(), getExecutorPluginClass(
  82                             executorParameterEntry.getValue().getTaskSelectionExecutorPluginClass()));
  83             stateFinalizerExecutorPluginClassMap.put(executorParameterEntry.getKey(), getExecutorPluginClass(
  84                             executorParameterEntry.getValue().getStateFinalizerExecutorPluginClass()));
  85
  86             // Save the executor implementation parameters
  87             implementationParameterMap.put(executorParameterEntry.getKey(), executorParameterEntry.getValue());
  88         }
  89     }
  90
  91     /*
  92      * (non-Javadoc)
  93      *
  94      * @see
  95      * org.onap.policy.apex.core.engine.executor.ExecutorFactory#getTaskSelectionExecutor(org.onap.policy.apex.core.
  96      * model. concepts.AxState, org.onap.policy.apex.core.engine.context.Context)
  97      */
  98     @Override
  99     public TaskSelectExecutor getTaskSelectionExecutor(final Executor<?, ?, ?, ?> parentExecutor, final AxState state,
 100                     final ApexInternalContext context) {
 101         if (!state.checkSetTaskSelectionLogic()) {
 102             return null;
 103         }
 104
 105         // Create task selection executor
 106         final TaskSelectExecutor tsExecutor = (TaskSelectExecutor) createExecutor(
 107                         state.getTaskSelectionLogic().getLogicFlavour(),
 108                         taskSelectionExecutorPluginClassMap.get(state.getTaskSelectionLogic().getLogicFlavour()),
 109                         TaskSelectExecutor.class);
 110         tsExecutor.setParameters(implementationParameterMap.get(state.getTaskSelectionLogic().getLogicFlavour()));
 111         tsExecutor.setContext(parentExecutor, state, context);
 112
 113         return tsExecutor;
 114     }
 115
 116     /*
 117      * (non-Javadoc)
 118      *
 119      * @see org.onap.policy.apex.core.engine.executor.ExecutorFactory#getTaskExecutor(org.onap.policy.apex.core.model.
 120      * concepts. AxTask, org.onap.policy.apex.core.engine.context.Context)
 121      */
 122     @Override
 123     public TaskExecutor getTaskExecutor(final Executor<?, ?, ?, ?> parentExecutor, final AxTask task,
 124                     final ApexInternalContext context) {
 125         // Create task executor
 126         final TaskExecutor taskExecutor = (TaskExecutor) createExecutor(task.getTaskLogic().getLogicFlavour(),
 127                         taskExecutorPluginClassMap.get(task.getTaskLogic().getLogicFlavour()), TaskExecutor.class);
 128         taskExecutor.setParameters(implementationParameterMap.get(task.getTaskLogic().getLogicFlavour()));
 129         taskExecutor.setContext(parentExecutor, task, context);
 130
 131         return taskExecutor;
 132     }
 133
 134     /*
 135      * (non-Javadoc)
 136      *
 137      * @see
 138      * org.onap.policy.apex.core.engine.executor.ExecutorFactory#getStateFinalizerExecutor(org.onap.policy.apex.core.
 139      * engine. executor.Executor, org.onap.policy.apex.core.policymodel.concepts.AxStateFinalizerLogic,
 140      * org.onap.policy.apex.core.engine.context.ApexInternalContext)
 141      */
 142     @Override
 143     public StateFinalizerExecutor getStateFinalizerExecutor(final Executor<?, ?, ?, ?> parentExecutor,
 144                     final AxStateFinalizerLogic logic, final ApexInternalContext context) {
 145         // Create state finalizer executor
 146         final StateFinalizerExecutor sfExecutor = (StateFinalizerExecutor) createExecutor(logic.getLogicFlavour(),
 147                         stateFinalizerExecutorPluginClassMap.get(logic.getLogicFlavour()),
 148                         StateFinalizerExecutor.class);
 149         sfExecutor.setParameters(implementationParameterMap.get(logic.getLogicFlavour()));
 150         sfExecutor.setContext(parentExecutor, logic, context);
 151
 152         return sfExecutor;
 153     }
 154
 155     /**
 156      * Get an executor class for a given executor plugin class name.
 157      *
 158      * @param executorClassName The name of the executor plugin class
 159      * @return an executor class
 160      * @throws StateMachineException on plugin instantiation errors
 161      */
 162     @SuppressWarnings("unchecked")
 163     private Class<Executor<?, ?, ?, ?>> getExecutorPluginClass(final String executorClassName)
 164                     throws StateMachineException {
 165         // It's OK for an executor class not to be defined as long as it's not called
 166         if (executorClassName == null) {
 167             return null;
 168         }
 169
 170         // Get the class for the executor using reflection
 171         Class<? extends Object> executorPluginClass = null;
 172         try {
 173             executorPluginClass = Class.forName(executorClassName);
 174         } catch (final ClassNotFoundException e) {
 175             LOGGER.error("Apex executor class not found for executor plugin \"" + executorClassName + "\"", e);
 176             throw new StateMachineException(
 177                             "Apex executor class not found for executor plugin \"" + executorClassName + "\"", e);
 178         }
 179
 180         // Check the class is an executor
 181         if (!Executor.class.isAssignableFrom(executorPluginClass)) {
 182             LOGGER.error("Specified Apex executor plugin class \"{}\" does not implment the Executor interface",
 183                             executorClassName);
 184             throw new StateMachineException("Specified Apex executor plugin class \"" + executorClassName
 185                             + "\" does not implment the Executor interface");
 186         }
 187
 188         return (Class<Executor<?, ?, ?, ?>>) executorPluginClass;
 189     }
 190
 191     /**
 192      * Get an instance of an executor plugin class of the specified type and super type.
 193      *
 194      * @param logicFlavour The logic flavour of the logic
 195      * @param executorClass The sub-class of the executor type to be instantiated
 196      * @param executorSuperClass The super type of the class of executor to be instantiated
 197      * @return The instantiated class
 198      */
 199     private Executor<?, ?, ?, ?> createExecutor(final String logicFlavour,
 200                     final Class<Executor<?, ?, ?, ?>> executorClass,
 201                     final Class<? extends Executor<?, ?, ?, ?>> executorSuperClass) {
 202         // It's OK for an executor class not to be defined but it's not all right to try and create
 203         // a non-defined
 204         // executor class
 205         if (executorClass == null) {
 206             final String errorMessage = "Executor plugin class not defined for \"" + logicFlavour
 207                             + "\" executor of type \"" + executorSuperClass.getCanonicalName() + "\"";
 208             LOGGER.error(errorMessage);
 209             throw new StateMachineRuntimeException(errorMessage);
 210         }
 211
 212         // Create an executor for the specified logic flavour
 213         Object executorObject = null;
 214         try {
 215             executorObject = executorClass.newInstance();
 216         } catch (InstantiationException | IllegalAccessException e) {
 217             final String errorMessage = "Instantiation error on \"" + logicFlavour + "\" executor of type \""
 218                             + executorClass.getCanonicalName() + "\"";
 219             LOGGER.error(errorMessage, e);
 220             throw new StateMachineRuntimeException(errorMessage, e);
 221         }
 222
 223         // Check the class is the correct type of executor
 224         if (!(executorSuperClass.isAssignableFrom(executorObject.getClass()))) {
 225             final String errorMessage = "Executor on \"" + logicFlavour + "\" of type \"" + executorClass
 226                             + "\" is not an instance of \"" + executorSuperClass.getCanonicalName() + "\"";
 227
 228             LOGGER.error(errorMessage);
 229             throw new StateMachineRuntimeException(errorMessage);
 230         }
 231
 232         return (Executor<?, ?, ?, ?>) executorObject;
 233     }
 234 }