001 /**
002 * Copyright 2005-2011 The Kuali Foundation
003 *
004 * Licensed under the Educational Community License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/ecl2.php
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016 package org.kuali.rice.krms.framework.engine;
017
018 import java.util.Map;
019
020 import org.joda.time.DateTime;
021 import org.kuali.rice.krms.api.engine.Engine;
022 import org.kuali.rice.krms.api.engine.EngineResults;
023 import org.kuali.rice.krms.api.engine.ExecutionEnvironment;
024 import org.kuali.rice.krms.api.engine.ExecutionOptions;
025 import org.kuali.rice.krms.api.engine.Facts;
026 import org.kuali.rice.krms.api.engine.ResultEvent;
027 import org.kuali.rice.krms.api.engine.SelectionCriteria;
028 import org.kuali.rice.krms.api.engine.Term;
029 import org.kuali.rice.krms.framework.engine.result.TimingResult;
030
031 public class ProviderBasedEngine implements Engine {
032
033 private static final Term effectiveExecutionTimeTerm = new Term("effectiveExecutionTime", null);
034
035 private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(ProviderBasedEngine.class);
036 private static final ResultLogger KLog = ResultLogger.getInstance();
037
038 private ContextProvider contextProvider;
039
040 @Override
041 public EngineResults execute(SelectionCriteria selectionCriteria, Map<String, Object> facts,
042 ExecutionOptions executionOptions) {
043 return execute(selectionCriteria,
044 Facts.Builder.create().addFactsByName(facts).build(),
045 executionOptions);
046 }
047
048 @Override
049 public EngineResults execute(SelectionCriteria selectionCriteria, Facts facts, ExecutionOptions executionOptions) {
050 DateTime start, end;
051 start = new DateTime();
052 ExecutionEnvironment environment = establishExecutionEnvironment(selectionCriteria, facts.getFactMap(), executionOptions);
053
054 // set execution time
055 Long effectiveExecutionTime = environment.getSelectionCriteria().getEffectiveExecutionTime();
056 if (effectiveExecutionTime == null) { effectiveExecutionTime = System.currentTimeMillis(); }
057 environment.publishFact(effectiveExecutionTimeTerm, effectiveExecutionTime);
058
059 Context context = selectContext(selectionCriteria, facts.getFactMap(), executionOptions);
060 if (context == null) {
061 LOG.info("Failed to locate a Context for the given qualifiers, skipping rule engine execution: " + selectionCriteria.getContextQualifiers());
062 return null;
063 }
064 context.execute(environment);
065 end = new DateTime();
066 if (KLog.isEnabled(environment)){
067 KLog.logResult(new TimingResult(ResultEvent.TimingEvent, this, environment, start, end));
068 }
069 return environment.getEngineResults();
070 }
071
072 protected ExecutionEnvironment establishExecutionEnvironment(SelectionCriteria selectionCriteria, Map<Term, Object> facts, ExecutionOptions executionOptions) {
073 return new BasicExecutionEnvironment(selectionCriteria, facts, executionOptions, new TermResolutionEngineImpl());
074 }
075
076 protected Context selectContext(SelectionCriteria selectionCriteria, Map<Term, Object> facts, ExecutionOptions executionOptions) {
077 if (contextProvider == null) {
078 throw new IllegalStateException("No ContextProvider was configured.");
079 }
080 return contextProvider.loadContext(selectionCriteria, facts, executionOptions);
081 }
082
083
084 public void setContextProvider(ContextProvider contextProvider) {
085 this.contextProvider = contextProvider;
086 }
087
088 }