Java tutorial
/** * Copyright 2014 Groupon.com * * 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 models.protocol.v2; import com.arpnetworking.metrics.Metrics; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.SerializationFeature; import com.fasterxml.jackson.databind.node.ArrayNode; import com.fasterxml.jackson.databind.node.ObjectNode; import com.fasterxml.jackson.datatype.joda.JodaModule; import com.google.common.collect.Maps; import com.google.common.collect.Sets; import models.ConnectionContext; import models.messages.Command; import models.messages.LogLine; import models.messages.LogReport; import models.messages.LogsList; import models.messages.LogsListRequest; import models.messages.NewLog; import models.protocol.MessagesProcessor; import play.Logger; import java.nio.file.Path; import java.nio.file.Paths; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.Set; import java.util.regex.Pattern; /** * Processes log-based messages. * * @author Brandon Arp (barp at groupon dot com) */ public class LogMessagesProcessor implements MessagesProcessor { /** * Public constructor. * * @param connectionContext ConnectionContext where processing takes place */ public LogMessagesProcessor(final ConnectionContext connectionContext) { _connectionContext = connectionContext; } /** * {@inheritDoc} */ @Override public boolean handleMessage(final Object message) { if (message instanceof Command) { //TODO(barp): Map with a POJO mapper [MAI-184] final Command command = (Command) message; final ObjectNode commandNode = (ObjectNode) command.getCommand(); final String commandString = commandNode.get("command").asText(); switch (commandString) { case COMMAND_GET_LOGS: _metrics.incrementCounter(GET_LOGS_COUNTER); _connectionContext.getContext().parent().tell(new LogsListRequest(), _connectionContext.getSelf()); break; case COMMAND_SUBSCRIBE_LOG: { _metrics.incrementCounter(SUBSCRIBE_COUNTER); final Path log = Paths.get(commandNode.get("log").asText()); final ArrayNode regexes = commandNode.withArray("regexes"); subscribe(log, regexes); break; } case COMMAND_UNSUBSCRIBE_LOG: { _metrics.incrementCounter(UNSUBSCRIBE_COUNTER); final Path log = Paths.get(commandNode.get("log").asText()); final ArrayNode regexes = commandNode.withArray("regexes"); unsubscribe(log, regexes); break; } default: return false; } } else if (message instanceof LogLine) { final LogLine logReport = (LogLine) message; processLogReport(logReport); } else if (message instanceof NewLog) { final NewLog newLog = (NewLog) message; processNewLog(newLog); } else if (message instanceof LogsList) { final LogsList logsList = (LogsList) message; processLogsList(logsList); } else { return false; } return true; } /** * {@inheritDoc} */ @Override public void initializeMetrics(final Metrics metrics) { _metrics = metrics; _metrics.resetCounter(GET_LOGS_COUNTER); _metrics.resetCounter(SUBSCRIBE_COUNTER); _metrics.resetCounter(UNSUBSCRIBE_COUNTER); _metrics.resetCounter(LOG_REPORT_COUNTER); _metrics.resetCounter(NEW_LOG_COUNTER); _metrics.resetCounter(LOGS_LIST_COUNTER); } private void processLogsList(final LogsList logsList) { _metrics.incrementCounter(LOGS_LIST_COUNTER); _connectionContext.sendCommand(COMMAND_LOGS_LIST, OBJECT_MAPPER.convertValue(logsList, ObjectNode.class)); } private void processLogReport(final LogLine rawReport) { final Path logFile = rawReport.getFile(); _metrics.incrementCounter(LOG_REPORT_COUNTER); final Set<String> regexes = _logsSubscriptions.get(logFile); if (regexes == null) { if (Logger.isTraceEnabled()) { Logger.trace( String.format("Not sending LogReport, log [%s] not found in _logsSubscriptions", logFile)); } return; } if (regexes.isEmpty()) { if (Logger.isTraceEnabled()) { Logger.trace(String.format( "Not sending LogReport, log [%s] has not subscribed regexes in _logsSubscriptions", logFile)); } return; } final List<String> matchingRegexes = new ArrayList<>(); for (final String regex : regexes) { final Pattern pattern = PATTERNS_MAP.get(regex); if (pattern.matcher(rawReport.getLine()).matches()) { matchingRegexes.add(regex); } } if (matchingRegexes.size() > 0) { final LogReport logReport = new LogReport(matchingRegexes, logFile, rawReport.getLine(), rawReport.getTimestamp()); _connectionContext.sendCommand(COMMAND_REPORT_LOG, OBJECT_MAPPER.convertValue(logReport, ObjectNode.class)); } } private void processNewLog(final NewLog newLog) { _metrics.incrementCounter(NEW_LOG_COUNTER); _connectionContext.sendCommand(COMMAND_NEW_LOG, OBJECT_MAPPER.convertValue(newLog, ObjectNode.class)); } private void subscribe(final Path log, final ArrayNode regexes) { if (!_logsSubscriptions.containsKey(log)) { _logsSubscriptions.put(log, Sets.<String>newHashSet()); } final Set<String> logsRegexes = _logsSubscriptions.get(log); for (JsonNode node : regexes) { final String regex = node.asText(); logsRegexes.add(regex); if (!PATTERNS_MAP.containsKey(regex)) { PATTERNS_MAP.put(regex, Pattern.compile(regex)); } } } private void unsubscribe(final Path log, final ArrayNode regexes) { if (!_logsSubscriptions.containsKey(log)) { return; } final Set<String> logsRegexes = _logsSubscriptions.get(log); for (JsonNode node : regexes) { logsRegexes.remove(node.asText()); } } private final Map<Path, Set<String>> _logsSubscriptions = Maps.newHashMap(); private final ConnectionContext _connectionContext; private Metrics _metrics; private static final Map<String, Pattern> PATTERNS_MAP = Maps.newHashMap(); private static final String COMMAND_GET_LOGS = "getLogs"; private static final String COMMAND_SUBSCRIBE_LOG = "subscribeLog"; private static final String COMMAND_UNSUBSCRIBE_LOG = "unsubscribeLog"; private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper(); private static final String COMMAND_LOGS_LIST = "logsList"; private static final String COMMAND_REPORT_LOG = "reportLog"; private static final String COMMAND_NEW_LOG = "newLog"; private static final String METRICS_PREFIX = "MessageProcessor/Log/"; private static final String LOGS_LIST_COUNTER = METRICS_PREFIX + "ListLog"; private static final String NEW_LOG_COUNTER = METRICS_PREFIX + "NewLog"; private static final String LOG_REPORT_COUNTER = METRICS_PREFIX + "LogReport"; private static final String SUBSCRIBE_COUNTER = METRICS_PREFIX + "Subscribe"; private static final String UNSUBSCRIBE_COUNTER = METRICS_PREFIX + "Unsubscribe"; private static final String GET_LOGS_COUNTER = METRICS_PREFIX + "Command/GetLogs"; static { OBJECT_MAPPER.registerModule(new JodaModule()); OBJECT_MAPPER.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS); } }