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.nio.charset.Charset;
020import java.nio.charset.StandardCharsets;
021
022import org.apache.logging.log4j.core.LogEvent;
023
024/**
025 * Abstract base class for Layouts that result in a String.
026 */
027public abstract class AbstractStringLayout extends AbstractLayout<String> {
028
029    private static final long serialVersionUID = 1L;
030
031    /**
032     * Converts a String to a byte[].
033     * 
034     * @param str
035     *            if null, return null.
036     * @param charset
037     *            if null, use the default charset.
038     * @return a byte[]
039     */
040    static byte[] toBytes(final String str, final Charset charset) {
041        if (str != null) {
042            return str.getBytes(charset != null ? charset : Charset.defaultCharset());
043        }
044        return null;
045    }
046
047    /**
048     * The charset for the formatted message.
049     */
050    // TODO: Charset is not serializable. Implement read/writeObject() ?
051    private final Charset charset;
052
053    protected AbstractStringLayout(final Charset charset) {
054        this(charset, null, null);
055    }
056
057    protected AbstractStringLayout(final Charset charset, final byte[] header, final byte[] footer) {
058        super(header, footer);
059        this.charset = charset == null ? StandardCharsets.UTF_8 : charset;
060    }
061
062    protected byte[] getBytes(final String s) {
063        return s.getBytes(charset);
064    }
065
066    protected Charset getCharset() {
067        return charset;
068    }
069
070    /**
071     * @return The default content type for Strings.
072     */
073    @Override
074    public String getContentType() {
075        return "text/plain";
076    }
077
078    /**
079     * Formats the Log Event as a byte array.
080     *
081     * @param event
082     *        The Log Event.
083     * @return The formatted event as a byte array.
084     */
085    @Override
086    public byte[] toByteArray(final LogEvent event) {
087        return toSerializable(event).getBytes(charset);
088    }
089
090}