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Diffstat (limited to 'java/broker/src/main/java/org/apache/qpid/server/logging/log4j/LoggingManagementFacade.java')
| -rw-r--r-- | java/broker/src/main/java/org/apache/qpid/server/logging/log4j/LoggingManagementFacade.java | 579 |
1 files changed, 579 insertions, 0 deletions
diff --git a/java/broker/src/main/java/org/apache/qpid/server/logging/log4j/LoggingManagementFacade.java b/java/broker/src/main/java/org/apache/qpid/server/logging/log4j/LoggingManagementFacade.java new file mode 100644 index 0000000000..6a961c8fa4 --- /dev/null +++ b/java/broker/src/main/java/org/apache/qpid/server/logging/log4j/LoggingManagementFacade.java @@ -0,0 +1,579 @@ +/* + * + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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 org.apache.qpid.server.logging.log4j; + +import org.apache.log4j.Level; +import org.apache.log4j.LogManager; +import org.apache.log4j.Logger; +import org.apache.log4j.xml.DOMConfigurator; +import org.apache.log4j.xml.Log4jEntityResolver; +import org.w3c.dom.Document; +import org.w3c.dom.Element; +import org.w3c.dom.NodeList; +import org.xml.sax.ErrorHandler; +import org.xml.sax.SAXException; +import org.xml.sax.SAXParseException; + +import javax.xml.parsers.DocumentBuilder; +import javax.xml.parsers.DocumentBuilderFactory; +import javax.xml.parsers.ParserConfigurationException; +import javax.xml.transform.OutputKeys; +import javax.xml.transform.Transformer; +import javax.xml.transform.TransformerConfigurationException; +import javax.xml.transform.TransformerException; +import javax.xml.transform.TransformerFactory; +import javax.xml.transform.dom.DOMSource; +import javax.xml.transform.stream.StreamResult; + +import java.io.File; +import java.io.FileOutputStream; +import java.io.IOException; +import java.util.ArrayList; +import java.util.Enumeration; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.Random; + +/** + * A facade over log4j that allows both the control of the runtime logging behaviour (that is, the ability to + * turn {@link Logger} on, off and control their {@link Level}, and the manipulation and reload + * of the log4j configuration file. + */ +public class LoggingManagementFacade +{ + private static Logger LOGGER; + private static transient LoggingManagementFacade _instance; + private final String _filename; + private final int _delay; + + public static LoggingManagementFacade configure(String filename) throws LoggingFacadeException + { + _instance = new LoggingManagementFacade(filename); + return _instance; + } + + public static LoggingManagementFacade configureAndWatch(String filename, int delay) throws LoggingFacadeException + { + _instance = new LoggingManagementFacade(filename, delay); + return _instance; + } + + public static LoggingManagementFacade getCurrentInstance() + { + return _instance; + } + + private LoggingManagementFacade(String filename) + { + DOMConfigurator.configure(filename); + + if(LOGGER == null) + { + LOGGER = Logger.getLogger(LoggingManagementFacade.class); + } + _filename = filename; + _delay = 0; + } + + private LoggingManagementFacade(String filename, int delay) + { + DOMConfigurator.configureAndWatch(filename, delay); + + if(LOGGER == null) + { + LOGGER = Logger.getLogger(LoggingManagementFacade.class); + } + + _filename = filename; + _delay = delay; + } + + public int getLog4jLogWatchInterval() + { + return _delay; + } + + public synchronized void reload() throws LoggingFacadeException + { + DOMConfigurator.configure(_filename); + } + + /** The log4j XML configuration file DTD defines three possible element + * combinations for specifying optional logger+level settings. + * Must account for the following: + * + * <category name="x"> <priority value="y"/> </category> OR + * <category name="x"> <level value="y"/> </category> OR + * <logger name="x"> <level value="y"/> </logger> + * + * Noting also that the level/priority child element is optional too, + * and not the only possible child element. + */ + public synchronized Map<String,String> retrieveConfigFileLoggersLevels() throws LoggingFacadeException + { + try + { + Map<String,String> loggerLevelList = new HashMap<String,String>(); + LOGGER.info("Getting logger levels from log4j configuration file"); + + Document doc = parseConfigFile(_filename); + List<Element> categoryOrLoggerElements = buildListOfCategoryOrLoggerElements(doc); + + for (Element categoryOrLogger : categoryOrLoggerElements) + { + + Element priorityOrLevelElement; + try + { + priorityOrLevelElement = getPriorityOrLevelElement(categoryOrLogger); + } + catch (LoggingFacadeException lfe) + { + //there is no exiting priority or level to view, move onto next category/logger + continue; + } + + String categoryName = categoryOrLogger.getAttribute("name"); + String priorityOrLevelValue = priorityOrLevelElement.getAttribute("value"); + loggerLevelList.put(categoryName, priorityOrLevelValue); + } + + return loggerLevelList; + } + catch (IOException e) + { + throw new LoggingFacadeException(e); + } + } + + /** + * The log4j XML configuration file DTD defines 2 possible element + * combinations for specifying the optional root logger level settings + * Must account for the following: + * + * <root> <priority value="y"/> </root> OR + * <root> <level value="y"/> </root> + * + * Noting also that the level/priority child element is optional too, + * and not the only possible child element. + */ + public synchronized String retrieveConfigFileRootLoggerLevel() throws LoggingFacadeException + { + try + { + Document doc = parseConfigFile(_filename); + + //retrieve the optional 'root' element node + NodeList rootElements = doc.getElementsByTagName("root"); + + if (rootElements.getLength() == 0) + { + //there is no root logger definition + return "N/A"; + } + + Element rootElement = (Element) rootElements.item(0); + Element levelElement = getPriorityOrLevelElement(rootElement); + + if(levelElement != null) + { + return levelElement.getAttribute("value"); + } + else + { + return "N/A"; + } + } + catch (IOException e) + { + throw new LoggingFacadeException(e); + } + } + + public synchronized void setConfigFileLoggerLevel(String logger, String level) throws LoggingFacadeException + { + LOGGER.info("Setting level to " + level + " for logger '" + logger + + "' in log4j xml configuration file: " + _filename); + + try + { + Document doc = parseConfigFile(_filename); + + List<Element> logElements = buildListOfCategoryOrLoggerElements(doc); + + //try to locate the specified logger/category in the elements retrieved + Element logElement = null; + for (Element e : logElements) + { + if (e.getAttribute("name").equals(logger)) + { + logElement = e; + break; + } + } + + if (logElement == null) + { + throw new LoggingFacadeException("Can't find logger " + logger); + } + + Element levelElement = getPriorityOrLevelElement(logElement); + + //update the element with the new level/priority + levelElement.setAttribute("value", level); + + //output the new file + writeUpdatedConfigFile(_filename, doc); + } + catch (IOException ioe) + { + throw new LoggingFacadeException(ioe); + } + catch (TransformerConfigurationException e) + { + throw new LoggingFacadeException(e); + } + } + + public synchronized void setConfigFileRootLoggerLevel(String level) throws LoggingFacadeException + { + try + { + LOGGER.info("Setting level to " + level + " for the Root logger in " + + "log4j xml configuration file: " + _filename); + + Document doc = parseConfigFile(_filename); + + //retrieve the optional 'root' element node + NodeList rootElements = doc.getElementsByTagName("root"); + + if (rootElements.getLength() == 0) + { + throw new LoggingFacadeException("Configuration contains no root element"); + } + + Element rootElement = (Element) rootElements.item(0); + Element levelElement = getPriorityOrLevelElement(rootElement); + + //update the element with the new level/priority + levelElement.setAttribute("value", level); + + //output the new file + writeUpdatedConfigFile(_filename, doc); + } + catch (IOException e) + { + throw new LoggingFacadeException(e); + } + catch (TransformerConfigurationException e) + { + throw new LoggingFacadeException(e); + } + } + + public List<String> getAvailableLoggerLevels() + { + return new ArrayList<String>() + {{ + add(Level.ALL.toString()); + add(Level.TRACE.toString()); + add(Level.DEBUG.toString()); + add(Level.INFO.toString()); + add(Level.WARN.toString()); + add(Level.ERROR.toString()); + add(Level.FATAL.toString()); + add(Level.OFF.toString()); + }}; + } + + public String retrieveRuntimeRootLoggerLevel() + { + Logger rootLogger = Logger.getRootLogger(); + return rootLogger.getLevel().toString(); + } + + public void setRuntimeRootLoggerLevel(String level) + { + Level newLevel = Level.toLevel(level); + + LOGGER.info("Setting RootLogger level to " + level); + + Logger log = Logger.getRootLogger(); + log.setLevel(newLevel); + } + + public void setRuntimeLoggerLevel(String loggerName, String level) throws LoggingFacadeException + { + Level newLevel = level == null ? null : Level.toLevel(level); + + Logger targetLogger = findRuntimeLogger(loggerName); + + if(targetLogger == null) + { + throw new LoggingFacadeException("Can't find logger " + loggerName); + } + + LOGGER.info("Setting level to " + newLevel + " for logger '" + targetLogger.getName() + "'"); + + targetLogger.setLevel(newLevel); + } + + public Map<String,String> retrieveRuntimeLoggersLevels() + { + LOGGER.info("Getting levels for currently active log4j loggers"); + + Map<String, String> levels = new HashMap<String, String>(); + @SuppressWarnings("unchecked") + Enumeration<Logger> loggers = LogManager.getCurrentLoggers(); + + while (loggers.hasMoreElements()) + { + Logger logger = loggers.nextElement(); + levels.put(logger.getName(), logger.getEffectiveLevel().toString()); + } + + return levels; + } + + private void writeUpdatedConfigFile(String log4jConfigFileName, Document doc) throws IOException, TransformerConfigurationException + { + File log4jConfigFile = new File(log4jConfigFileName); + + if (!log4jConfigFile.canWrite()) + { + LOGGER.warn("Specified log4j XML configuration file is not writable: " + log4jConfigFile); + throw new IOException("Specified log4j XML configuration file is not writable"); + } + + Transformer transformer = null; + transformer = TransformerFactory.newInstance().newTransformer(); + + transformer.setOutputProperty(OutputKeys.INDENT, "yes"); + transformer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, "log4j.dtd"); + DOMSource source = new DOMSource(doc); + + File tmp; + Random r = new Random(); + + do + { + tmp = new File(log4jConfigFile.getAbsolutePath() + r.nextInt() + ".tmp"); + } + while(tmp.exists()); + + tmp.deleteOnExit(); + + try + { + StreamResult result = new StreamResult(new FileOutputStream(tmp)); + transformer.transform(source, result); + } + catch (TransformerException e) + { + LOGGER.warn("Could not transform the XML into new file: ", e); + throw new IOException("Could not transform the XML into new file: ", e); + } + + // Swap temp file in to replace existing configuration file. + File old = new File(log4jConfigFile.getAbsoluteFile() + ".old"); + if (old.exists()) + { + old.delete(); + } + + if(!log4jConfigFile.renameTo(old)) + { + //unable to rename the existing file to the backup name + LOGGER.error("Could not backup the existing log4j XML file"); + throw new IOException("Could not backup the existing log4j XML file"); + } + + if(!tmp.renameTo(log4jConfigFile)) + { + //failed to rename the new file to the required filename + + if(!old.renameTo(log4jConfigFile)) + { + //unable to return the backup to required filename + LOGGER.error("Could not rename the new log4j configuration file into place, and unable to restore original file"); + throw new IOException("Could not rename the new log4j configuration file into place, and unable to restore original file"); + } + + LOGGER.error("Could not rename the new log4j configuration file into place"); + throw new IOException("Could not rename the new log4j configuration file into place"); + } + } + + //method to parse the XML configuration file, validating it in the process, and returning a DOM Document of the content. + private static Document parseConfigFile(String fileName) throws IOException + { + //check file was specified, exists, and is readable + if(fileName == null) + { + LOGGER.warn("Provided log4j XML configuration filename is null"); + throw new IOException("Provided log4j XML configuration filename is null"); + } + + File configFile = new File(fileName); + + if (!configFile.exists()) + { + LOGGER.warn("The log4j XML configuration file could not be found: " + fileName); + throw new IOException("The log4j XML configuration file could not be found"); + } + else if (!configFile.canRead()) + { + LOGGER.warn("The log4j XML configuration file is not readable: " + fileName); + throw new IOException("The log4j XML configuration file is not readable"); + } + + //parse it + DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance(); + DocumentBuilder docBuilder; + Document doc; + + ErrorHandler errHandler = new QpidLog4JSaxErrorHandler(); + try + { + docFactory.setValidating(true); + docBuilder = docFactory.newDocumentBuilder(); + docBuilder.setErrorHandler(errHandler); + docBuilder.setEntityResolver(new Log4jEntityResolver()); + doc = docBuilder.parse(fileName); + } + catch (ParserConfigurationException e) + { + LOGGER.warn("Unable to parse the log4j XML file due to possible configuration error: ", e); + throw new IOException("Unable to parse the log4j XML file due to possible configuration error: ", e); + } + catch (SAXException e) + { + LOGGER.warn("The specified log4j XML file is invalid: ", e); + throw new IOException("The specified log4j XML file is invalid: ", e); + } + catch (IOException e) + { + LOGGER.warn("Unable to parse the specified log4j XML file", e); + throw new IOException("Unable to parse the specified log4j XML file: ", e); + } + + return doc; + } + + private Logger findRuntimeLogger(String loggerName) + { + Logger targetLogger = null; + @SuppressWarnings("unchecked") + Enumeration<Logger> loggers = LogManager.getCurrentLoggers(); + while(loggers.hasMoreElements()) + { + targetLogger = loggers.nextElement(); + if (targetLogger.getName().equals(loggerName)) + { + return targetLogger; + } + } + return null; + } + + private List<Element> buildListOfCategoryOrLoggerElements(Document doc) + { + //retrieve the 'category' and 'logger' element nodes + NodeList categoryElements = doc.getElementsByTagName("category"); + NodeList loggerElements = doc.getElementsByTagName("logger"); + + //collect them into a single elements list + List<Element> logElements = new ArrayList<Element>(); + + for (int i = 0; i < categoryElements.getLength(); i++) + { + logElements.add((Element) categoryElements.item(i)); + } + for (int i = 0; i < loggerElements.getLength(); i++) + { + logElements.add((Element) loggerElements.item(i)); + } + return logElements; + } + + private Element getPriorityOrLevelElement(Element categoryOrLogger) throws LoggingFacadeException + { + //retrieve the optional 'priority' or 'level' sub-element value. + //It may not be the only child node, so request by tag name. + NodeList priorityElements = categoryOrLogger.getElementsByTagName("priority"); + NodeList levelElements = categoryOrLogger.getElementsByTagName("level"); + + Element levelElement = null; + if (priorityElements.getLength() != 0) + { + levelElement = (Element) priorityElements.item(0); + } + else if (levelElements.getLength() != 0) + { + levelElement = (Element) levelElements.item(0); + } + else + { + throw new LoggingFacadeException("Configuration " + categoryOrLogger.getNodeName() + + " element contains neither priority nor level child"); + } + return levelElement; + } + + private static class QpidLog4JSaxErrorHandler implements ErrorHandler + { + public void error(SAXParseException e) throws SAXException + { + if(LOGGER != null) + { + LOGGER.warn(constructMessage("Error parsing XML file", e)); + } + else + { + System.err.println(constructMessage("Error parsing XML file", e)); + } + } + + public void fatalError(SAXParseException e) throws SAXException + { + throw new SAXException(constructMessage("Fatal error parsing XML file", e)); + } + + public void warning(SAXParseException e) throws SAXException + { + if(LOGGER != null) + { + LOGGER.warn(constructMessage("Warning parsing XML file", e)); + } + else + { + System.err.println(constructMessage("Warning parsing XML file", e)); + } + } + + private static String constructMessage(final String msg, final SAXParseException ex) + { + return msg + ": Line " + ex.getLineNumber()+" column " +ex.getColumnNumber() + ": " + ex.getMessage(); + } + } +} + |