Java tutorial
/** * Copyright 2015 Otto (GmbH & Co KG) * * 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 com.ottogroup.bi.spqr.operator.esper; import java.io.IOException; import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.Map; import java.util.Properties; import java.util.Set; import org.apache.commons.lang3.StringUtils; import org.apache.log4j.Logger; import com.espertech.esper.client.Configuration; import com.espertech.esper.client.EPRuntime; import com.espertech.esper.client.EPServiceProvider; import com.espertech.esper.client.EPServiceProviderManager; import com.espertech.esper.client.EPStatement; import com.espertech.esper.client.EPStatementException; import com.fasterxml.jackson.core.type.TypeReference; import com.fasterxml.jackson.databind.ObjectMapper; import com.ottogroup.bi.spqr.exception.ComponentInitializationFailedException; import com.ottogroup.bi.spqr.exception.RequiredInputMissingException; import com.ottogroup.bi.spqr.pipeline.component.MicroPipelineComponentType; import com.ottogroup.bi.spqr.pipeline.component.annotation.SPQRComponent; import com.ottogroup.bi.spqr.pipeline.component.operator.DelayedResponseOperator; import com.ottogroup.bi.spqr.pipeline.component.operator.DelayedResponseOperatorWaitStrategy; import com.ottogroup.bi.spqr.pipeline.message.StreamingDataMessage; /** * Integrates the {@link http://espertech.com/ ESPER} project into SPQR pipelines. * @author mnxfst * @since Apr 23, 2015 */ @SPQRComponent(type = MicroPipelineComponentType.DELAYED_RESPONSE_OPERATOR, name = "esperOperator", version = "0.0.1", description = "ESPER integration operator") public class EsperOperator implements DelayedResponseOperator { /** our faithful logging facility ... ;-) */ private static final Logger logger = Logger.getLogger(EsperOperator.class); public static final String SPQR_EVENT_TIMESTAMP_FIELD = "timestamp"; public static final String SPQR_EVENT_BODY_FIELD = "body"; public static final String DEFAULT_INPUT_EVENT = "spqrIn"; public static final String DEFAULT_OUTPUT_EVENT = "spqrOut"; public static final String CFG_ESPER_STATEMENT_PREFIX = "esper.statement."; public static final String CFG_ESPER_TYPE_DEF_PREFIX = "esper.typeDef."; public static final String CFG_ESPER_TYPE_DEF_EVENT_SUFFIX = ".event"; public static final String CFG_ESPER_TYPE_DEF_NAME_SUFFIX = ".name"; public static final String CFG_ESPER_TYPE_DEF_TYPE_SUFFIX = ".type"; private String id = null; private long totalNumOfMessages = 0; private long numOfMessagesSinceLastResult = 0; private DelayedResponseOperatorWaitStrategy waitStrategy = null; private EPServiceProvider esperServiceProvider = null; private EPRuntime esperRuntime = null; private final ObjectMapper mapper = new ObjectMapper(); private StreamingDataMessage[] result = null; /** * @see com.ottogroup.bi.spqr.pipeline.component.MicroPipelineComponent#initialize(java.util.Properties) */ public void initialize(Properties properties) throws RequiredInputMissingException, ComponentInitializationFailedException { if (properties == null) throw new RequiredInputMissingException("Missing required properties"); ///////////////////////////////////////////////////////////////////////////////// // fetch an validate properties Set<String> esperQueryStrings = new HashSet<>(); for (int i = 1; i < Integer.MAX_VALUE; i++) { String tmpStr = properties.getProperty(CFG_ESPER_STATEMENT_PREFIX + i); if (StringUtils.isBlank(tmpStr)) break; esperQueryStrings.add(StringUtils.trim(tmpStr)); } if (esperQueryStrings.isEmpty()) throw new RequiredInputMissingException("Missing required ESPER statement(s)"); ///////////////////////////////////////////////////////////////////////////////// ///////////////////////////////////////////////////////////////////////////////// // fetch event configuration Map<String, Map<String, String>> eventConfiguration = new HashMap<>(); for (int i = 1; i < Integer.MAX_VALUE; i++) { final String typeDefEvent = StringUtils .trim(properties.getProperty(CFG_ESPER_TYPE_DEF_PREFIX + i + CFG_ESPER_TYPE_DEF_EVENT_SUFFIX)); if (StringUtils.isBlank(typeDefEvent)) break; final String typeDefName = StringUtils .trim(properties.getProperty(CFG_ESPER_TYPE_DEF_PREFIX + i + CFG_ESPER_TYPE_DEF_NAME_SUFFIX)); final String typeDefType = StringUtils .trim(properties.getProperty(CFG_ESPER_TYPE_DEF_PREFIX + i + CFG_ESPER_TYPE_DEF_TYPE_SUFFIX)); if (StringUtils.isBlank(typeDefName) || StringUtils.isBlank(typeDefType)) throw new RequiredInputMissingException( "Missing type def name or type for event '" + typeDefEvent + "' at position " + i); Map<String, String> ec = eventConfiguration.get(typeDefEvent); if (ec == null) ec = new HashMap<>(); ec.put(typeDefName, typeDefType); eventConfiguration.put(typeDefEvent, ec); } /////////////////////////////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////////////////////////////// // create esper configuration Configuration esperConfiguration = new Configuration(); for (final String event : eventConfiguration.keySet()) { Map<String, String> ec = eventConfiguration.get(event); if (ec != null && !ec.isEmpty()) { Map<String, Object> typeDefinition = new HashMap<>(); for (final String typeDefName : ec.keySet()) { final String typeDefType = ec.get(typeDefName); try { typeDefinition.put(typeDefName, Class.forName(typeDefType)); } catch (ClassNotFoundException e) { throw new ComponentInitializationFailedException("Failed to lookup provided type '" + typeDefType + "' for event '" + event + "'. Error: " + e.getMessage()); } } esperConfiguration.addEventType(event, typeDefinition); } } Map<String, Object> spqrDefaultTypeDefinition = new HashMap<>(); spqrDefaultTypeDefinition.put(SPQR_EVENT_TIMESTAMP_FIELD, Long.class); spqrDefaultTypeDefinition.put(SPQR_EVENT_BODY_FIELD, Map.class); esperConfiguration.addEventType(DEFAULT_INPUT_EVENT, spqrDefaultTypeDefinition); esperConfiguration.addEventType(DEFAULT_OUTPUT_EVENT, spqrDefaultTypeDefinition); /////////////////////////////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////////////////////////////// // initialize service provider, submit statements and retrieve runtime this.esperServiceProvider = EPServiceProviderManager.getDefaultProvider(esperConfiguration); this.esperServiceProvider.initialize(); for (final String qs : esperQueryStrings) { try { EPStatement esperStatement = this.esperServiceProvider.getEPAdministrator().createEPL(qs); esperStatement.setSubscriber(this); } catch (EPStatementException e) { throw new ComponentInitializationFailedException( "Failed to parse query into ESPER statement. Error: " + e.getMessage(), e); } } this.esperRuntime = this.esperServiceProvider.getEPRuntime(); /////////////////////////////////////////////////////////////////////////////////// } /** * @see com.ottogroup.bi.spqr.pipeline.component.MicroPipelineComponent#shutdown() */ public boolean shutdown() { return false; } /** * @see com.ottogroup.bi.spqr.pipeline.component.MicroPipelineComponent#getType() */ public MicroPipelineComponentType getType() { return MicroPipelineComponentType.DELAYED_RESPONSE_OPERATOR; } /** * @see com.ottogroup.bi.spqr.pipeline.component.operator.DelayedResponseOperator#onMessage(com.ottogroup.bi.spqr.pipeline.message.StreamingDataMessage) */ public void onMessage(StreamingDataMessage message) { if (message == null || message.getBody() == null) return; Map<String, Object> event = new HashMap<String, Object>(); event.put("timestamp", message.getTimestamp()); try { event.put("body", mapper.readValue(message.getBody(), new TypeReference<Map<String, Object>>() { })); } catch (IOException e) { logger.error("Failed to parse incoming message to structured JSON map. Error: " + e.getMessage()); event.put("body", Collections.emptyMap()); } this.esperRuntime.sendEvent(event, DEFAULT_INPUT_EVENT); this.numOfMessagesSinceLastResult++; this.totalNumOfMessages++; } /** * @see com.ottogroup.bi.spqr.pipeline.component.operator.DelayedResponseOperator#getResult() */ public StreamingDataMessage[] getResult() { this.numOfMessagesSinceLastResult = 0; return result; } /** * Callback invoked by ESPER for nay result * @param eventMap */ public void update(Map<String, Object> eventMap) { @SuppressWarnings("unchecked") Map<String, Object> body = eventMap; Long timestamp = (Long) eventMap.get(SPQR_EVENT_TIMESTAMP_FIELD); if (body != null) { try { byte[] messageBody = mapper.writeValueAsBytes(body); if (messageBody != null && messageBody.length > 0) { result = new StreamingDataMessage[] { new StreamingDataMessage(messageBody, (timestamp != null ? timestamp.longValue() : System.currentTimeMillis())) }; this.waitStrategy.release(); } } catch (IOException e) { logger.error("Failed to parse ESPER result to JSON representation. Error: " + e.getMessage(), e); } } } /** * @see com.ottogroup.bi.spqr.pipeline.component.operator.DelayedResponseOperator#getNumberOfMessagesSinceLastResult() */ public long getNumberOfMessagesSinceLastResult() { return this.numOfMessagesSinceLastResult; } /** * @see com.ottogroup.bi.spqr.pipeline.component.operator.Operator#getTotalNumOfMessages() */ public long getTotalNumOfMessages() { return this.totalNumOfMessages; } /** * @see com.ottogroup.bi.spqr.pipeline.component.MicroPipelineComponent#setId(java.lang.String) */ public void setId(String id) { this.id = id; } /** * @see com.ottogroup.bi.spqr.pipeline.component.MicroPipelineComponent#getId() */ public String getId() { return this.id; } /** * @see com.ottogroup.bi.spqr.pipeline.component.operator.DelayedResponseOperator#setWaitStrategy(com.ottogroup.bi.spqr.pipeline.component.operator.DelayedResponseOperatorWaitStrategy) */ public void setWaitStrategy(DelayedResponseOperatorWaitStrategy waitStrategy) { this.waitStrategy = waitStrategy; } }