Java tutorial
/* * Lilith - a log event viewer. * Copyright (C) 2007-2016 Joern Huxhorn * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ /* * Copyright 2007-2016 Joern Huxhorn * * 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 de.huxhorn.lilith.log4j.xml; import de.huxhorn.lilith.data.eventsource.EventIdentifier; import de.huxhorn.lilith.data.eventsource.EventWrapper; import de.huxhorn.lilith.data.eventsource.SourceIdentifier; import de.huxhorn.lilith.data.logging.LoggingEvent; import de.huxhorn.sulky.buffers.AppendOperation; import de.huxhorn.sulky.tasks.AbstractProgressingCallable; import java.io.BufferedReader; import java.io.ByteArrayInputStream; import java.io.File; import java.io.FileInputStream; import java.io.InputStreamReader; import java.nio.charset.StandardCharsets; import java.util.Locale; import java.util.zip.GZIPInputStream; import javax.xml.stream.XMLInputFactory; import javax.xml.stream.XMLStreamException; import javax.xml.stream.XMLStreamReader; import org.apache.commons.io.input.CountingInputStream; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class Log4jImportCallable extends AbstractProgressingCallable<Long> { // thread-safe, see http://www.cowtowncoder.com/blog/archives/2006/06/entry_2.html static final XMLInputFactory XML_INPUT_FACTORY = XMLInputFactory.newFactory(); static { XML_INPUT_FACTORY.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, false); XML_INPUT_FACTORY.setProperty(XMLInputFactory.SUPPORT_DTD, false); XML_INPUT_FACTORY.setProperty(XMLInputFactory.IS_VALIDATING, false); } private final Logger logger = LoggerFactory.getLogger(Log4jImportCallable.class); public static final String CLOSING_LOG4J_EVENT_TAG = "</log4j:event>"; public static final String LOG4J_NAMESPACE = "xmlns:log4j=\"http://jakarta.apache.org/log4j/\""; public static final String OPENING_LOG4J_EVENT_TAG_EXCL_NS = "<log4j:event "; public static final String OPENING_LOG4J_EVENT_TAG_INCL_NS = OPENING_LOG4J_EVENT_TAG_EXCL_NS + LOG4J_NAMESPACE + " "; private File inputFile; private AppendOperation<EventWrapper<LoggingEvent>> buffer; private LoggingEventReader instance; private long result; public Log4jImportCallable(File inputFile, AppendOperation<EventWrapper<LoggingEvent>> buffer) { this.buffer = buffer; this.inputFile = inputFile; instance = new LoggingEventReader(); } public AppendOperation<EventWrapper<LoggingEvent>> getBuffer() { return buffer; } public File getInputFile() { return inputFile; } public Long call() throws Exception { if (!inputFile.isFile()) { throw new IllegalArgumentException("'" + inputFile.getAbsolutePath() + "' is not a file!"); } if (!inputFile.canRead()) { throw new IllegalArgumentException("'" + inputFile.getAbsolutePath() + "' is not a readable!"); } long fileSize = inputFile.length(); setNumberOfSteps(fileSize); FileInputStream fis = new FileInputStream(inputFile); CountingInputStream cis = new CountingInputStream(fis); String fileName = inputFile.getName().toLowerCase(Locale.US); BufferedReader br; if (fileName.endsWith(".gz")) { br = new BufferedReader(new InputStreamReader(new GZIPInputStream(cis), StandardCharsets.UTF_8)); } else { br = new BufferedReader(new InputStreamReader(cis, StandardCharsets.UTF_8)); } StringBuilder builder = new StringBuilder(); result = 0; for (;;) { String line = br.readLine(); setCurrentStep(cis.getByteCount()); if (line == null) { evaluate(builder.toString()); break; } for (;;) { int closeIndex = line.indexOf(CLOSING_LOG4J_EVENT_TAG); if (closeIndex >= 0) { int endIndex = closeIndex + CLOSING_LOG4J_EVENT_TAG.length(); builder.append(line.subSequence(0, endIndex)); evaluate(builder.toString()); builder.setLength(0); line = line.substring(endIndex); } else { builder.append(line); builder.append("\n"); break; } } } return result; } private void evaluate(String eventStr) { eventStr = prepare(eventStr); try { LoggingEvent event = readEvent(eventStr); if (event != null) { result++; EventWrapper<LoggingEvent> wrapper = new EventWrapper<>(); wrapper.setEvent(event); SourceIdentifier sourceIdentifier = new SourceIdentifier(inputFile.getAbsolutePath()); EventIdentifier eventId = new EventIdentifier(sourceIdentifier, result); wrapper.setEventIdentifier(eventId); buffer.add(wrapper); } } catch (XMLStreamException e) { // ignore } } private String prepare(String eventStr) { if (!eventStr.contains(LOG4J_NAMESPACE)) { eventStr = eventStr.replace(OPENING_LOG4J_EVENT_TAG_EXCL_NS, OPENING_LOG4J_EVENT_TAG_INCL_NS); if (logger.isDebugEnabled()) logger.debug("After change: {}", eventStr); } return eventStr; } private LoggingEvent readEvent(String eventStr) throws XMLStreamException { byte[] bytes = eventStr.getBytes(StandardCharsets.UTF_8); ByteArrayInputStream in = new ByteArrayInputStream(bytes); XMLStreamReader reader = XML_INPUT_FACTORY .createXMLStreamReader(new InputStreamReader(in, StandardCharsets.UTF_8)); return instance.read(reader); } }