public synchronized String format(LogRecord record) 
{
                                                    
        StringBuffer sb = new StringBuffer();
        // Minimize memory allocations here.
        dat.setTime(record.getMillis());
        args[0] = dat;
        StringBuffer text = new StringBuffer();
        if (formatter == null) {
            formatter = new MessageFormat(format);
        }
        formatter.format(args, text, null);
        sb.append(text);
        sb.append(" ");
        if (record.getSourceClassName() != null) {
            sb.append(record.getSourceClassName());
        } else {
            sb.append(record.getLoggerName());
        }
        if (record.getSourceMethodName() != null) {
            sb.append(" ");
            sb.append(record.getSourceMethodName());
        }
        sb.append(lineSeparator);
        String message = formatMessage(record);
        sb.append(record.getLevel().getLocalizedName());
        sb.append(": ");
        sb.append(message);
        sb.append(lineSeparator);
        if (record.getThrown() != null) {
            try {
                StringWriter sw = new StringWriter();
                PrintWriter pw = new PrintWriter(sw);
                record.getThrown().printStackTrace(pw);
                pw.close();
                sb.append(sw.toString());
            } catch (Exception ex) {
            }
        }
        return sb.toString();
}

Format the given LogRecord.

This method can be overridden in a subclass. It is recommended to use the Formatter#formatMessage convenience method to localize and format the message field.