| /* |
| * 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.logging.log4j.core; |
| |
| import java.io.Serializable; |
| |
| /** |
| * Appends {@link LogEvent}s. An Appender can contain a {@link Layout} if applicable as well |
| * as an {@link ErrorHandler}. Typical Appender implementations coordinate with an |
| * implementation of {@link org.apache.logging.log4j.core.appender.AbstractManager} to handle external resources |
| * such as streams, connections, and other shared state. As Appenders are plugins, concrete implementations need to |
| * be annotated with {@link org.apache.logging.log4j.plugins.Plugin} and need to provide a static |
| * factory method annotated with {@link org.apache.logging.log4j.plugins.PluginFactory}. |
| * |
| * <p>Most core plugins are written using a related Manager class that handle the actual task of serializing a |
| * {@link LogEvent} to some output location. For instance, many Appenders can take |
| * advantage of the {@link org.apache.logging.log4j.core.appender.OutputStreamManager} class.</p> |
| * |
| * <p>It is recommended that Appenders don't do any heavy lifting since there can be many instances of the class |
| * being used at any given time. When resources require locking (e.g., through {@link java.nio.channels.FileLock}), |
| * it is important to isolate synchronized code to prevent concurrency issues.</p> |
| */ |
| public interface Appender extends LifeCycle { |
| |
| /** |
| * Main {@linkplain org.apache.logging.log4j.plugins.Plugin#elementType() plugin element type} for |
| * Appender plugins. |
| * |
| * @since 2.6 |
| */ |
| String ELEMENT_TYPE = "appender"; |
| |
| /** |
| * Logs a LogEvent using whatever logic this Appender wishes to use. It is typically recommended to use a |
| * bridge pattern not only for the benefits from decoupling an Appender from its implementation, but it is also |
| * handy for sharing resources which may require some form of locking. |
| * |
| * @param event The LogEvent. |
| */ |
| void append(LogEvent event); |
| |
| |
| /** |
| * Gets the name of this Appender. |
| * |
| * @return name, may be null. |
| */ |
| String getName(); |
| |
| /** |
| * Returns the Layout used by this Appender if applicable. |
| * |
| * @return the Layout for this Appender or {@code null} if none is configured. |
| */ |
| Layout<? extends Serializable> getLayout(); |
| |
| /** |
| * Some Appenders need to propagate exceptions back to the application. When {@code ignoreExceptions} is |
| * {@code false} the AppenderControl will allow the exception to percolate. |
| * |
| * @return {@code true} if exceptions will be logged but not thrown, {@code false} otherwise. |
| */ |
| boolean ignoreExceptions(); |
| |
| /** |
| * Gets the {@link ErrorHandler} used for handling exceptions. |
| * |
| * @return the ErrorHandler for handling exceptions. |
| */ |
| ErrorHandler getHandler(); |
| |
| /** |
| * Sets the {@link ErrorHandler} used for handling exceptions. |
| * |
| * @param handler the ErrorHandler to use for handling exceptions. |
| */ |
| void setHandler(ErrorHandler handler); |
| |
| /** |
| * Appenders should return true if they require location information. |
| * @return true if the Appender requires location information. |
| */ |
| default boolean requiresLocation() { |
| return false; |
| } |
| } |