import java.text.SimpleDateFormat;   

import org.apache.log4j.HTMLLayout;

import org.apache.log4j.Layout;

import org.apache.log4j.Level;

import org.apache.log4j.helpers.Transform;

import org.apache.log4j.spi.LocationInfo;

import org.apache.log4j.spi.LoggingEvent;   

public class HtmlLogFormat extends HTMLLayout {   

    public HtmlLogFormat() {

    }   

    protected final int BUF_SIZE = 256;   

    protected final int MAX_CAPACITY = 1024;   

    static String TRACE_PREFIX = "<br>&nbsp;&nbsp;&nbsp;&nbsp;";   

    private StringBuffer sbuf = new StringBuffer(BUF_SIZE);   

    String title="Automation Log";   

    /**

     * A string constant used in naming the option for setting the the HTML

     * document title. Current value of this string constant is <b>Title</b>.

     */

    public static final String TITLE_OPTION = "Title";   

    // Print no location info by default

    boolean locationInfo = true;   

    public String format(LoggingEvent event) {

        if (sbuf.capacity() > MAX_CAPACITY) {

            sbuf = new StringBuffer(BUF_SIZE);

        } else {

            sbuf.setLength(0);

        }

        sbuf.append(Layout.LINE_SEP + "<tr>" + Layout.LINE_SEP);   

        sbuf.append("<td>");

        sbuf.append(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new java.util.Date()));

        sbuf.append("</td>" + Layout.LINE_SEP);   

        sbuf.append("<td title=\"Level\">");

        if (event.getLevel().equals(Level.FATAL)) {

            sbuf.append("<font color=\"#339933\">");

            sbuf.append(Transform.escapeTags(String.valueOf(event.getLevel())));

            sbuf.append("</font>");

        } else if (event.getLevel().isGreaterOrEqual(Level.WARN)) {

            sbuf.append("<font color=\"#993300\"><strong>");

            sbuf.append(Transform.escapeTags(String.valueOf(event.getLevel())));

            sbuf.append("</strong></font>");

        } else {

            sbuf.append("<font color=\"green\">");

            sbuf.append(Transform.escapeTags(String.valueOf(event.getLevel())));

            sbuf.append("</font>");

        }

        sbuf.append("</td>" + Layout.LINE_SEP);   

   if (locationInfo) {

            LocationInfo locInfo = event.getLocationInformation();

            sbuf.append("<td title=\"Source\">");

            sbuf.append(Transform.escapeTags(locInfo.getFileName()));

            sbuf.append(':');

            sbuf.append(locInfo.getLineNumber());

            sbuf.append("</td>" + Layout.LINE_SEP);

        }  

        sbuf.append("<td title=\"Message\">");

        sbuf.append(Transform.escapeTags(event.getRenderedMessage()));

        sbuf.append("</td>" + Layout.LINE_SEP);

        sbuf.append("</tr>" + Layout.LINE_SEP);   

        if (event.getNDC() != null) {

            sbuf.append("<tr><td bgcolor=\"#EEEEEE\" style=\"font-size : xx-small;\" colspan=\"6\" title=\"Nested Diagnostic Context\">");

            sbuf.append("NDC: " + Transform.escapeTags(event.getNDC()));

            sbuf.append("</td></tr>" + Layout.LINE_SEP);

        }   

        String[] s = event.getThrowableStrRep();

        if (s != null) {

            sbuf.append("<tr><td bgcolor=\"#993300\" style=\"color:White; font-size : xx-small;\" colspan=\"4\">");

            appendThrowableAsHTML(s, sbuf);

            sbuf.append("</td></tr>" + Layout.LINE_SEP);

        }

        return sbuf.toString();

    }   

    private void appendThrowableAsHTML(String[] s,StringBuffer sbuf){

        if (s != null) {

            int len = s.length;

            if (len == 0)

                return;

            sbuf.append(Transform.escapeTags(s[0]));

            sbuf.append(Layout.LINE_SEP);

            for (int i = 1; i < len; i++) {

                sbuf.append(TRACE_PREFIX);

                sbuf.append(Transform.escapeTags(s[i]));

                sbuf.append(Layout.LINE_SEP);

            }

        }

    }   

    /**

     * Returns appropriate HTML headers.

     */

    public String getHeader() {

        StringBuffer sbuf = new StringBuffer();

        sbuf.append("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\">" + Layout.LINE_SEP);

        sbuf.append("<html>" + Layout.LINE_SEP);

        sbuf.append("<head>" + Layout.LINE_SEP);

        sbuf.append("<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\">" + Layout.LINE_SEP);

        sbuf.append("<title>" + title + "</title>" + Layout.LINE_SEP);

        sbuf.append("<style type=\"text/css\">" + Layout.LINE_SEP);

        sbuf.append("<!--" + Layout.LINE_SEP);

        sbuf.append("body, table {font-family: '??',arial,sans-serif; font-size: 12px;}" + Layout.LINE_SEP);

        sbuf.append("th {background: #336699; color: #FFFFFF; text-align: left;}" + Layout.LINE_SEP);

        sbuf.append("-->" + Layout.LINE_SEP);

        sbuf.append("</style>" + Layout.LINE_SEP);

        sbuf.append("</head>" + Layout.LINE_SEP);

        sbuf.append("<body bgcolor=\"#FFFFFF\" topmargin=\"6\" leftmargin=\"6\">" + Layout.LINE_SEP);   

        sbuf.append("<table cellspacing=\"0\" cellpadding=\"4\" border=\"1\" bordercolor=\"#224466\" width=\"100%\">" + Layout.LINE_SEP);

        sbuf.append("<tr>" + Layout.LINE_SEP);   

        sbuf.append("<th width='120'>Time</th>" + Layout.LINE_SEP);

        sbuf.append("<th>Level</th>" + Layout.LINE_SEP);   

        if (locationInfo) {

            sbuf.append("<th>Source</th>" + Layout.LINE_SEP);

        }   

        sbuf.append("<th>Message</th>" + Layout.LINE_SEP);

        sbuf.append("</tr>" + Layout.LINE_SEP);

        sbuf.append("<br></br>" + Layout.LINE_SEP);

        return sbuf.toString();

    }   

}