001/**
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
004 *
005 * This program and the accompanying materials are dual-licensed under
006 * either the terms of the Eclipse Public License v1.0 as published by
007 * the Eclipse Foundation
008 *
009 *   or (per the licensee's choosing)
010 *
011 * under the terms of the GNU Lesser General Public License version 2.1
012 * as published by the Free Software Foundation.
013 */
014package ch.qos.logback.core.encoder;
015
016import java.nio.charset.Charset;
017
018import ch.qos.logback.core.CoreConstants;
019import ch.qos.logback.core.Layout;
020import ch.qos.logback.core.OutputStreamAppender;
021import ch.qos.logback.core.spi.ContextAware;
022
023public class LayoutWrappingEncoder<E> extends EncoderBase<E> {
024
025    protected Layout<E> layout;
026
027    /**
028     * The charset to use when converting a String into bytes.
029     * <p>
030     * By default this property has the value {@code null} which corresponds to the
031     * system's default charset.
032     */
033    private Charset charset;
034
035    ContextAware parent;
036    Boolean immediateFlush = null;
037
038    public Layout<E> getLayout() {
039        return layout;
040    }
041
042    public void setLayout(Layout<E> layout) {
043        this.layout = layout;
044    }
045
046    public Charset getCharset() {
047        return charset;
048    }
049
050    /**
051     * Set the charset to use when converting the string returned by the layout into
052     * bytes.
053     * <p>
054     * By default this property has the value {@code null} which corresponds to the
055     * system's default charset.
056     *
057     * @param charset
058     */
059    public void setCharset(Charset charset) {
060        this.charset = charset;
061    }
062
063    /**
064     * Sets the immediateFlush option. The default value for immediateFlush is
065     * 'true'. If set to true, the doEncode() method will immediately flush the
066     * underlying OutputStream. Although immediate flushing is safer, it also
067     * significantly degrades logging throughput.
068     *
069     * @since 1.0.3
070     */
071    public void setImmediateFlush(boolean immediateFlush) {
072        addWarn("As of version 1.2.0 \"immediateFlush\" property should be set within the enclosing Appender.");
073        addWarn("Please move \"immediateFlush\" property into the enclosing appender.");
074        this.immediateFlush = immediateFlush;
075    }
076
077    @Override
078    public byte[] headerBytes() {
079        if (layout == null)
080            return null;
081
082        StringBuilder sb = new StringBuilder();
083        appendIfNotNull(sb, layout.getFileHeader());
084        appendIfNotNull(sb, layout.getPresentationHeader());
085        if (sb.length() > 0) {
086            // If at least one of file header or presentation header were not
087            // null, then append a line separator.
088            // This should be useful in most cases and should not hurt.
089            sb.append(CoreConstants.LINE_SEPARATOR);
090        }
091        return convertToBytes(sb.toString());
092    }
093
094    @Override
095    public byte[] footerBytes() {
096        if (layout == null)
097            return null;
098
099        StringBuilder sb = new StringBuilder();
100        appendIfNotNull(sb, layout.getPresentationFooter());
101        appendIfNotNull(sb, layout.getFileFooter());
102        return convertToBytes(sb.toString());
103    }
104
105    private byte[] convertToBytes(String s) {
106        if (charset == null) {
107            return s.getBytes();
108        } else {
109            return s.getBytes(charset);
110        }
111    }
112
113    public byte[] encode(E event) {
114        String txt = layout.doLayout(event);
115        return convertToBytes(txt);
116    }
117
118    public boolean isStarted() {
119        return started;
120    }
121
122    public void start() {
123        if (immediateFlush != null) {
124            if (parent instanceof OutputStreamAppender) {
125                addWarn("Setting the \"immediateFlush\" property of the enclosing appender to " + immediateFlush);
126                @SuppressWarnings("unchecked")
127                OutputStreamAppender<E> parentOutputStreamAppender = (OutputStreamAppender<E>) parent;
128                parentOutputStreamAppender.setImmediateFlush(immediateFlush);
129            } else {
130                addError("Could not set the \"immediateFlush\" property of the enclosing appender.");
131            }
132        }
133        started = true;
134    }
135
136    public void stop() {
137        started = false;
138    }
139
140    private void appendIfNotNull(StringBuilder sb, String s) {
141        if (s != null) {
142            sb.append(s);
143        }
144    }
145
146    /**
147     * This method allows RollingPolicy implementations to be aware of their
148     * containing appender.
149     * 
150     * @param parent
151     */
152    public void setParent(ContextAware parent) {
153        this.parent = parent;
154    }
155}