001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.logging.log4j.core.layout;
018
019import java.io.Serializable;
020
021import org.apache.logging.log4j.Logger;
022import org.apache.logging.log4j.core.Layout;
023import org.apache.logging.log4j.status.StatusLogger;
024
025/**
026 * Abstract base class for Layouts.
027 * 
028 * @param <T>
029 *        The Class that the Layout will format the LogEvent into.
030 */
031public abstract class AbstractLayout<T extends Serializable> implements Layout<T> {
032
033    /**
034     * Constructs a layout with an optional header and footer.
035     * 
036     * @param header
037     *        The header to include when the stream is opened. May be null.
038     * @param footer
039     *        The footer to add when the stream is closed. May be null.
040     */
041    public AbstractLayout(byte[] header, byte[] footer) {
042        super();
043        this.header = header;
044        this.footer = footer;
045    }
046
047    /**
048     * Allow subclasses access to the status logger without creating another instance.
049     */
050    protected static final Logger LOGGER = StatusLogger.getLogger();
051
052    /**
053     * The header to include when the stream is opened. May be null.
054     */
055    protected final byte[] header;
056
057    /**
058     * The footer to add when the stream is closed. May be null.
059     */
060    protected final byte[] footer;
061
062    /**
063     * Returns the header, if one is available.
064     * 
065     * @return A byte array containing the header.
066     */
067    @Override
068    public byte[] getHeader() {
069        return header;
070    }
071
072    /**
073     * Returns the footer, if one is available.
074     * 
075     * @return A byte array containing the footer.
076     */
077    @Override
078    public byte[] getFooter() {
079        return footer;
080    }
081}