HTMLLayout.java

/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2013, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.classic.html;

import java.util.Map;

import ch.qos.logback.classic.PatternLayout;
import ch.qos.logback.classic.pattern.MDCConverter;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.classic.html.DefaultCssBuilder;
import ch.qos.logback.core.html.HTMLLayoutBase;
import ch.qos.logback.core.html.IThrowableRenderer;
import ch.qos.logback.core.pattern.Converter;
import static ch.qos.logback.core.CoreConstants.LINE_SEPARATOR;

/**
 * 
 * HTMLLayout outputs events in an HTML table. <p> The content of the table
 * columns are specified using a conversion pattern. See
 * {@link ch.qos.logback.classic.PatternLayout} for documentation on the
 * available patterns. <p> For more information about this layout, please refer
 * to the online manual at
 * http://logback.qos.ch/manual/layouts.html#ClassicHTMLLayout
 * 
 * @author Ceki Gülcü
 * @author Sébastien Pennec
 */
public class HTMLLayout extends HTMLLayoutBase<ILoggingEvent> {

  /**
   * Default pattern string for log output.
   */
  static final String DEFAULT_CONVERSION_PATTERN = "%date%thread%level%logger%mdc%msg";

  IThrowableRenderer<ILoggingEvent> throwableRenderer;

  /**
   * Constructs a PatternLayout using the DEFAULT_LAYOUT_PATTERN.
   * 
   * The default pattern just produces the application supplied message.
   */
  public HTMLLayout() {
    pattern = DEFAULT_CONVERSION_PATTERN;
    throwableRenderer = new DefaultThrowableRenderer();
    cssBuilder = new DefaultCssBuilder();
  }

  @Override
  public void start() {
    int errorCount = 0;
    if (throwableRenderer == null) {
      addError("ThrowableRender cannot be null.");
      errorCount++;
    }
    if (errorCount == 0) {
      super.start();
    }
  }

  protected Map<String, String> getDefaultConverterMap() {
    return PatternLayout.defaultConverterMap;
  }

  public String doLayout(ILoggingEvent event) {
    StringBuilder buf = new StringBuilder();
    startNewTableIfLimitReached(buf);

    boolean odd = true;
    if (((counter++) & 1) == 0) {
      odd = false;
    }

    String level = event.getLevel().toString().toLowerCase();

    buf.append(LINE_SEPARATOR);
    buf.append("<tr class=\"");
    buf.append(level);
    if (odd) {
      buf.append(" odd\">");
    } else {
      buf.append(" even\">");
    }
    buf.append(LINE_SEPARATOR);

    Converter<ILoggingEvent> c = head;
    while (c != null) {
      appendEventToBuffer(buf, c, event);
      c = c.getNext();
    }
    buf.append("</tr>");
    buf.append(LINE_SEPARATOR);

    if (event.getThrowableProxy() != null) {
      throwableRenderer.render(buf, event);
    }
    return buf.toString();
  }

  private void appendEventToBuffer(StringBuilder buf,
      Converter<ILoggingEvent> c, ILoggingEvent event) {
    buf.append("<td class=\"");
    buf.append(computeConverterName(c));
    buf.append("\">");
    c.write(buf, event);
    buf.append("</td>");
    buf.append(LINE_SEPARATOR);
  }

  public IThrowableRenderer getThrowableRenderer() {
    return throwableRenderer;
  }

  public void setThrowableRenderer(IThrowableRenderer<ILoggingEvent> throwableRenderer) {
    this.throwableRenderer = throwableRenderer;
  }
  
  @Override
  protected String computeConverterName(Converter c) {
    if(c instanceof MDCConverter) {
      MDCConverter mc = (MDCConverter) c;
      String key = mc.getFirstOption();
      if(key != null) {
        return key;
      } else {
        return "MDC";
      }
    } else {    
      return super.computeConverterName(c);
    }
  }
}