Java tutorial
/* * #%L * ACS AEM Commons Bundle * %% * Copyright (C) 2013 Adobe * %% * 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. * #L% */ package com.adobe.acs.commons.logging.impl; import java.util.Dictionary; import java.util.Hashtable; import org.apache.felix.scr.annotations.Activate; import org.apache.felix.scr.annotations.Component; import org.apache.felix.scr.annotations.ConfigurationPolicy; import org.apache.felix.scr.annotations.Deactivate; import org.apache.felix.scr.annotations.Properties; import org.apache.felix.scr.annotations.Property; import org.apache.felix.scr.annotations.PropertyUnbounded; import ch.qos.logback.core.net.SyslogAppenderBase; import org.apache.commons.lang.StringUtils; import org.apache.sling.commons.osgi.PropertiesUtil; import org.osgi.framework.BundleContext; import org.osgi.framework.ServiceRegistration; import org.osgi.service.component.ComponentContext; import ch.qos.logback.core.Appender; @Component(metatype = true, configurationFactory = true, policy = ConfigurationPolicy.REQUIRE, label = "ACS AEM Commons - Syslog Appender", description = "Logback appender to send messages using Syslog") @Properties({ @Property(name = "webconsole.configurationFactory.nameHint", value = "Host: {host}, for loggers [{loggers}]") }) public final class SyslogAppender { private static final String ROOT = "ROOT"; private static final int DEFAULT_PORT = -1; private static final String DEFAULT_SUFFIX_PATTERN = "[%thread] %-5level %logger{36} - %msg%n"; private static final String DEFAULT_FACILITY = "USER"; private static final boolean DEFAULT_THROWABLE_EXCLUDED = false; @Property(label = "Host", description = "Host of Syslog server") private static final String PROP_HOST = "host"; @Property(label = "Logger Names", description = "List of logger categories (ROOT for all)", unbounded = PropertyUnbounded.ARRAY, value = ROOT) private static final String PROP_LOGGERS = "loggers"; @Property(label = "Port", description = "Port of Syslog server", intValue = -1) private static final String PROP_PORT = "port"; @Property(label = "Suffix Pattern", description = "Logback Pattern defining the message format.", value = DEFAULT_SUFFIX_PATTERN) private static final String PROP_SUFFIX_PATTERN = "suffix.pattern"; @Property(label = "Syslog Facility", value = DEFAULT_FACILITY, propertyPrivate = true, description = "The Syslog Facility is meant to identify the source of a message, separately from any context " + "included in the Suffix Pattern. The facility option must be set to one of the strings KERN, USER, MAIL, DAEMON, " + "AUTH, SYSLOG, LPR, NEWS, UUCP, CRON, AUTHPRIV, FTP, NTP, AUDIT, ALERT, CLOCK, LOCAL0, LOCAL1, LOCAL2, LOCAL3, LOCAL4, " + "LOCAL5, LOCAL6, LOCAL7. Case is not important.") private static final String PROP_FACILITY = "facility"; @Property(label = "Stack Trace Pattern", description = "Logback Pattern for customizing the string appearing just before each stack " + "trace line. The default value for this property is a single tab character.") private static final String PROP_STACK_TRACE_PATTERN = "stack.trace.pattern"; @Property(label = "Exclude Throwables", description = "Set to true to cause stack trace data associated with a Throwable to be omitted. " + "By default, this is set to false so that stack trace data is sent to the syslog server.", boolValue = DEFAULT_THROWABLE_EXCLUDED) private static final String PROP_THROWABLE_EXCLUDED = "throwable.excluded"; private ch.qos.logback.classic.net.SyslogAppender appender; private ServiceRegistration appenderRegistration; @Activate @SuppressWarnings("squid:S1149") protected void activate(ComponentContext ctx) { final Dictionary<?, ?> properties = ctx.getProperties(); final String[] loggers = PropertiesUtil.toStringArray(properties.get(PROP_LOGGERS), new String[] { ROOT }); final String suffixPattern = PropertiesUtil.toString(properties.get(PROP_SUFFIX_PATTERN), DEFAULT_SUFFIX_PATTERN); final int port = PropertiesUtil.toInteger(properties.get(PROP_PORT), DEFAULT_PORT); final String host = PropertiesUtil.toString(properties.get(PROP_HOST), null); final String facility = PropertiesUtil.toString(properties.get(PROP_FACILITY), DEFAULT_FACILITY); final String stackTracePattern = PropertiesUtil.toString(properties.get(PROP_STACK_TRACE_PATTERN), null); final boolean throwableExcluded = PropertiesUtil.toBoolean(properties.get(PROP_THROWABLE_EXCLUDED), DEFAULT_THROWABLE_EXCLUDED); if (host == null || port == -1) { throw new IllegalArgumentException( "Syslog Appender not configured correctly. Both host and port need to be provided."); } // throws a descriptive IllegalArgumentException if facility is not valid. SyslogAppenderBase.facilityStringToint(facility); final BundleContext bundleContext = ctx.getBundleContext(); appender = new ch.qos.logback.classic.net.SyslogAppender(); appender.setSyslogHost(host); appender.setPort(port); appender.setFacility(facility); appender.setSuffixPattern(suffixPattern); if (StringUtils.isNotEmpty(stackTracePattern)) { appender.setStackTracePattern(stackTracePattern); } appender.setThrowableExcluded(throwableExcluded); Dictionary<String, Object> props = new Hashtable<String, Object>(); props.put("loggers", loggers); appenderRegistration = bundleContext.registerService(Appender.class.getName(), appender, props); } @Deactivate protected void deactivate() { if (appender != null) { appender.stop(); appender = null; } if (appenderRegistration != null) { appenderRegistration.unregister(); appenderRegistration = null; } } }