Java tutorial
/** * Copyright 2009 Red Hat, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package org.safehaus.penrose.log.log4j; import org.w3c.dom.*; import org.apache.commons.digester.Digester; import org.apache.commons.digester.xmlrules.DigesterLoader; import org.xml.sax.EntityResolver; import org.xml.sax.InputSource; import org.slf4j.LoggerFactory; import org.slf4j.Logger; import java.io.*; import java.net.URL; /** * @author Endi S. Dewata */ public class Log4jConfigReader implements EntityResolver { public Logger log = LoggerFactory.getLogger(getClass()); URL log4jDtdUrl; public Log4jConfigReader() throws Exception { ClassLoader cl = getClass().getClassLoader(); log4jDtdUrl = cl.getResource("org/apache/log4j/xml/log4j.dtd"); } public InputSource resolveEntity(String publicId, String systemId) throws IOException { int i = systemId.lastIndexOf("/"); String file = systemId.substring(i + 1); if ("log4j.dtd".equals(file)) { return new InputSource(log4jDtdUrl.openStream()); } return null; } public Log4jConfig read(File file) throws Exception { Reader reader = new FileReader(file); Log4jConfig config = new Log4jConfig(); ClassLoader cl = getClass().getClassLoader(); URL ruleUrl = cl.getResource("org/safehaus/penrose/log/log4j/log4j-digester-rules.xml"); Digester digester = DigesterLoader.createDigester(ruleUrl); digester.setEntityResolver(this); digester.setValidating(false); digester.setClassLoader(cl); digester.push(config); digester.parse(reader); reader.close(); return config; } public Log4jConfig createLog4jConfig(Document document) { Log4jConfig config = new Log4jConfig(); NodeList appenders = document.getElementsByTagName("appender"); for (int i = 0; i < appenders.getLength(); i++) { Element appenderElement = (Element) appenders.item(i); AppenderConfig appenderConfig = createAppenderConfig(appenderElement); config.addAppenderConfig(appenderConfig); } NodeList loggers = document.getElementsByTagName("logger"); for (int i = 0; i < loggers.getLength(); i++) { Element loggerElement = (Element) loggers.item(i); LoggerConfig loggerConfig = createLoggerConfig(loggerElement); config.addLoggerConfig(loggerConfig); } NodeList roots = document.getElementsByTagName("root"); if (roots.getLength() > 0) { Element rootElement = (Element) roots.item(0); RootLoggerConfig rootConfig = createRootConfig(rootElement); config.setRootLoggerConfig(rootConfig); } return config; } public AppenderConfig createAppenderConfig(Element element) { AppenderConfig appenderConfig = new AppenderConfig(); appenderConfig.setName(element.getAttribute("name")); appenderConfig.setAppenderClass(element.getAttribute("class")); NodeList params = element.getElementsByTagName("param"); for (int i = 0; i < params.getLength(); i++) { Element paramElement = (Element) params.item(i); String name = paramElement.getAttribute("name"); String value = paramElement.getAttribute("value"); appenderConfig.setParameter(name, value); } NodeList layouts = element.getElementsByTagName("layout"); if (layouts.getLength() > 0) { Element layoutElement = (Element) layouts.item(0); LayoutConfig layoutConfig = createLayoutConfig(layoutElement); appenderConfig.setLayoutConfig(layoutConfig); } return appenderConfig; } public LayoutConfig createLayoutConfig(Element element) { LayoutConfig layoutConfig = new LayoutConfig(); layoutConfig.setLayoutClass(element.getAttribute("class")); NodeList params = element.getElementsByTagName("param"); for (int i = 0; i < params.getLength(); i++) { Element paramElement = (Element) params.item(i); String name = paramElement.getAttribute("name"); String value = paramElement.getAttribute("value"); layoutConfig.setParameter(name, value); } return layoutConfig; } public LoggerConfig createLoggerConfig(Element element) { LoggerConfig loggerConfig = new LoggerConfig(); loggerConfig.setName(element.getAttribute("name")); loggerConfig.setAdditivity(Boolean.parseBoolean(element.getAttribute("additivity"))); NodeList levels = element.getElementsByTagName("level"); if (levels.getLength() > 0) { Element levelElement = (Element) levels.item(0); String level = levelElement.getAttribute("value"); loggerConfig.setLevel(level); } NodeList appenderRefs = element.getElementsByTagName("appender-ref"); for (int i = 0; i < appenderRefs.getLength(); i++) { Element appenderRef = (Element) appenderRefs.item(i); String appenderName = appenderRef.getAttribute("ref"); loggerConfig.addAppenderName(appenderName); } return loggerConfig; } public RootLoggerConfig createRootConfig(Element element) { RootLoggerConfig rootConfig = new RootLoggerConfig(); NodeList levels = element.getElementsByTagName("level"); if (levels.getLength() > 0) { Element levelElement = (Element) levels.item(0); String level = levelElement.getAttribute("value"); rootConfig.setLevel(level); } NodeList appenderRefs = element.getElementsByTagName("appender-ref"); for (int i = 0; i < appenderRefs.getLength(); i++) { Element appenderRef = (Element) appenderRefs.item(i); String appenderName = appenderRef.getAttribute("ref"); rootConfig.addAppender(appenderName); } return rootConfig; } public void print(Document document) { Element element = document.getDocumentElement(); print(0, element); } public void print(int level, Element node) { for (int i = 0; i < level; i++) { System.out.print(" "); } if (node instanceof Text) { System.out.println("Text: " + node.getNodeValue()); } else { System.out.println(node.getNodeName() + ": " + node.getNodeValue()); } NamedNodeMap map = node.getAttributes(); for (int i = 0; map != null && i < map.getLength(); i++) { Node n = map.item(i); System.out.println(" - " + n.getNodeName() + ": " + n.getNodeValue()); } NodeList list = node.getChildNodes(); for (int i = 0; i < list.getLength(); i++) { print(level + 1, (Element) list.item(i)); } } }