ConsoleOutLogger.cs :  » Persistence-Frameworks » iBATIS.NET » IBatisNet » Common » Logging » Impl » C# / CSharp Open Source

#region Apache Notice
/*****************************************************************************
 * $Header: $
 * $Revision: 474141 $
 * $Date: 2006-11-13 05:43:37 +0100 (lun., 13 nov. 2006) $
 * 
 * iBATIS.NET Data Mapper
 * Copyright (C) 2004 - Gilles Bayon
 *  
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 ********************************************************************************/
#endregion

using System;
using System.Globalization;
using System.Text;

namespace IBatisNet.Common.Logging.Impl{
  /// <summary>
  /// Sends log messages to <see cref="Console.Out" />.
  /// </summary>
  public class ConsoleOutLogger : AbstractLogger
  {
    private bool _showDateTime = false;
    private bool _showLogName = false;
    private string _logName = string.Empty;
    private LogLevel _currentLogLevel = LogLevel.All;
    private string _dateTimeFormat = string.Empty;
    private bool _hasDateTimeFormat = false;

    /// <summary>
    /// Creates and initializes a logger that writes messages to <see cref="Console.Out" />.
    /// </summary>
    /// <param name="logName">The name, usually type name of the calling class, of the logger.</param>
    /// <param name="logLevel">The current logging threshold. Messages recieved that are beneath this threshold will not be logged.</param>
    /// <param name="showDateTime">Include the current time in the log message.</param>
    /// <param name="showLogName">Include the instance name in the log message.</param>
    /// <param name="dateTimeFormat">The date and time format to use in the log message.</param>
    public ConsoleOutLogger( string logName, LogLevel logLevel
                             , bool showDateTime, bool showLogName, string dateTimeFormat)
    {
      _logName = logName;
      _currentLogLevel = logLevel;
      _showDateTime = showDateTime;
      _showLogName = showLogName;
      _dateTimeFormat = dateTimeFormat;

      if (_dateTimeFormat != null && _dateTimeFormat.Length > 0)
      {
        _hasDateTimeFormat = true;
      }
    }

    /// <summary>
    /// Do the actual logging by constructing the log message using a <see cref="StringBuilder" /> then
    /// sending the output to <see cref="Console.Out" />.
    /// </summary>
    /// <param name="level">The <see cref="LogLevel" /> of the message.</param>
    /// <param name="message">The log message.</param>
    /// <param name="e">An optional <see cref="Exception" /> associated with the message.</param>
    protected override void Write( LogLevel level, object message, Exception e )
    {
      // Use a StringBuilder for better performance
      StringBuilder sb = new StringBuilder();
      // Append date-time if so configured
      if ( _showDateTime )
      {
        if ( _hasDateTimeFormat )
        {
          sb.Append( DateTime.Now.ToString( _dateTimeFormat, CultureInfo.InvariantCulture ));
        }
        else
        {
          sb.Append( DateTime.Now );
        }
        
        sb.Append( " " );
      }  
      // Append a readable representation of the log level
      sb.Append( string.Format( "[{0}]", level.ToString().ToUpper() ).PadRight( 8 ) );

      // Append the name of the log instance if so configured
      if ( _showLogName )
      {
        sb.Append( _logName ).Append( " - " );
      }

      // Append the message
      sb.Append( message.ToString() );

      // Append stack trace if not null
      if ( e != null )
      {
        sb.Append(Environment.NewLine).Append( e.ToString() );
      }

      // Print to the appropriate destination
      Console.Out.WriteLine( sb.ToString() );
    }

    /// <summary>
    /// Determines if the given log level is currently enabled.
    /// </summary>
    /// <param name="level"></param>
    /// <returns></returns>
    protected override bool IsLevelEnabled( LogLevel level )
    {
      int iLevel = (int)level;
      int iCurrentLogLevel = (int)_currentLogLevel;
    
      // return iLevel.CompareTo(iCurrentLogLevel); better ???
      return ( iLevel >= iCurrentLogLevel );
    }
  }
}