| /* |
| * 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.jclouds.logging; |
| |
| /** |
| * JClouds log abstraction layer. |
| * <p/> |
| * Implementations of logging are optional and injected if they are configured. |
| * <p/> |
| * <code> @Resource Logger logger = Logger.NULL;</code> The above will get you a null-safe instance |
| * of <tt>Logger</tt>. If configured, this logger will be swapped with a real Logger implementation |
| * with category set to the current class name. This is done post-object construction, so do not |
| * attempt to use these loggers in your constructor. |
| * <p/> |
| * If you wish to initialize loggers like these yourself, do not use the @Resource annotation. |
| * <p/> |
| * This implementation first checks to see if the level is enabled before issuing the log command. |
| * In other words, don't do the following |
| * <code>if (logger.isTraceEnabled()) logger.trace("message");. |
| * <p/> |
| */ |
| public interface Logger { |
| |
| /** |
| * Assign to member to avoid NPE when no logging module is configured. |
| */ |
| Logger NULL = new NullLogger(); |
| |
| /** |
| * Assign to member to avoid NPE when no logging module is configured. |
| */ |
| Logger CONSOLE = new ConsoleLogger(); |
| |
| String getCategory(); |
| |
| void trace(String message, Object... args); |
| |
| boolean isTraceEnabled(); |
| |
| void debug(String message, Object... args); |
| |
| boolean isDebugEnabled(); |
| |
| void info(String message, Object... args); |
| |
| boolean isInfoEnabled(); |
| |
| void warn(String message, Object... args); |
| |
| void warn(Throwable throwable, String message, Object... args); |
| |
| boolean isWarnEnabled(); |
| |
| void error(String message, Object... args); |
| |
| void error(Throwable throwable, String message, Object... args); |
| |
| boolean isErrorEnabled(); |
| |
| /** |
| * Produces instances of {@link Logger} relevant to the specified category |
| * |
| * |
| */ |
| public interface LoggerFactory { |
| Logger getLogger(String category); |
| } |
| } |