udpappender.cs

精通SQL Server2005项目开发

#region Copyright & License
//
// Copyright 2001-2005 The Apache Software Foundation
//
// 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.Net;
using System.Net.Sockets;
using System.Text;

using log4net.Layout;
using log4net.Core;
using log4net.Util;

namespace log4net.Appender 
{
	/// <summary>
	/// Sends logging events as connectionless UDP datagrams to a remote host or a 
	/// multicast group using an <see cref="UdpClient" />.
	/// </summary>
	/// <remarks>
	/// <para>
	/// UDP guarantees neither that messages arrive, nor that they arrive in the correct order.
	/// </para>
	/// <para>
	/// To view the logging results, a custom application can be developed that listens for logging 
	/// events.
	/// </para>
	/// <para>
	/// When decoding events send via this appender remember to use the same encoding
	/// to decode the events as was used to send the events. See the <see cref="Encoding"/>
	/// property to specify the encoding to use.
	/// </para>
	/// </remarks>
	/// <example>
	/// This example shows how to log receive logging events that are sent 
	/// on IP address 244.0.0.1 and port 8080 to the console. The event is 
	/// encoded in the packet as a unicode string and it is decoded as such. 
	/// <code lang="C#">
	/// IPEndPoint remoteEndPoint = new IPEndPoint(IPAddress.Any, 0);
	/// UdpClient udpClient;
	/// byte[] buffer;
	/// string loggingEvent;
	/// 
	/// try 
	/// {
	///     udpClient = new UdpClient(8080);
	///     
	///     while(true) 
	///     {
	///         buffer = udpClient.Receive(ref remoteEndPoint);
	///         loggingEvent = System.Text.Encoding.Unicode.GetString(buffer);
	///         Console.WriteLine(loggingEvent);
	///     }
	/// } 
	/// catch(Exception e) 
	/// {
	///     Console.WriteLine(e.ToString());
	/// }
	/// </code>
	/// <code lang="Visual Basic">
	/// Dim remoteEndPoint as IPEndPoint
	/// Dim udpClient as UdpClient
	/// Dim buffer as Byte()
	/// Dim loggingEvent as String
	/// 
	/// Try 
	///     remoteEndPoint = new IPEndPoint(IPAddress.Any, 0)
	///     udpClient = new UdpClient(8080)
	///
	///     While True
	///         buffer = udpClient.Receive(ByRef remoteEndPoint)
	///         loggingEvent = System.Text.Encoding.Unicode.GetString(buffer)
	///         Console.WriteLine(loggingEvent)
	///     Wend
	/// Catch e As Exception
	///     Console.WriteLine(e.ToString())
	/// End Try
	/// </code>
	/// <para>
	/// An example configuration section to log information using this appender to the 
	/// IP 224.0.0.1 on port 8080:
	/// </para>
	/// <code lang="XML" escaped="true">
	/// <appender name="UdpAppender" type="log4net.Appender.UdpAppender">
	///     <remoteAddress value="224.0.0.1" />
	///     <remotePort value="8080" />
	///     <layout type="log4net.Layout.PatternLayout" value="%-5level %logger [%ndc] - %message%newline" />
	/// </appender>
	/// </code>
	/// </example>
	/// <author>Gert Driesen</author>
	/// <author>Nicko Cadell</author>
	public class UdpAppender : AppenderSkeleton
	{
		#region Public Instance Constructors

		/// <summary>
		/// Initializes a new instance of the <see cref="UdpAppender" /> class.
		/// </summary>
		/// <remarks>
		/// The default constructor initializes all fields to their default values.
		/// </remarks>
		public UdpAppender() 
		{
		}

		#endregion Public Instance Constructors

		#region Public Instance Properties

		/// <summary>
		/// Gets or sets the IP address of the remote host or multicast group to which
		/// the underlying <see cref="UdpClient" /> should sent the logging event.
		/// </summary>
		/// <value>
		/// The IP address of the remote host or multicast group to which the logging event 
		/// will be sent.
		/// </value>
		/// <remarks>
		/// <para>
		/// Multicast addresses are identified by IP class <b>D</b> addresses (in the range 224.0.0.0 to
		/// 239.255.255.255).  Multicast packets can pass across different networks through routers, so
		/// it is possible to use multicasts in an Internet scenario as long as your network provider 
		/// supports multicasting.
		/// </para>
		/// <para>
		/// Hosts that want to receive particular multicast messages must register their interest by joining
		/// the multicast group.  Multicast messages are not sent to networks where no host has joined
		/// the multicast group.  Class <b>D</b> IP addresses are used for multicast groups, to differentiate
		/// them from normal host addresses, allowing nodes to easily detect if a message is of interest.
		/// </para>
		/// <para>
		/// Static multicast addresses that are needed globally are assigned by IANA.  A few examples are listed in the table below:
		/// </para>
		/// <para>
		/// <list type="table">
		///     <listheader>
		///         <term>IP Address</term>
		///         <description>Description</description>
		///     </listheader>
		///     <item>
		///         <term>224.0.0.1</term>
		///         <description>
		///             <para>
		///             Sends a message to all system on the subnet.
		///             </para>
		///         </description>
		///     </item>
		///     <item>
		///         <term>224.0.0.2</term>
		///         <description>
		///             <para>
		///             Sends a message to all routers on the subnet.
		///             </para>
		///         </description>
		///     </item>
		///     <item>
		///         <term>224.0.0.12</term>
		///         <description>
		///             <para>
		///             The DHCP server answers messages on the IP address 224.0.0.12, but only on a subnet.
		///             </para>
		///         </description>
		///     </item>
		/// </list>
		/// </para>
		/// <para>
		/// A complete list of actually reserved multicast addresses and their owners in the ranges
		/// defined by RFC 3171 can be found at the <A href="http://www.iana.org/assignments/multicast-addresses">IANA web site</A>. 
		/// </para>
		/// <para>
		/// The address range 239.0.0.0 to 239.255.255.255 is reserved for administrative scope-relative 
		/// addresses.  These addresses can be reused with other local groups.  Routers are typically 
		/// configured with filters to prevent multicast traffic in this range from flowing outside
		/// of the local network.
		/// </para>
		/// </remarks>
		public IPAddress RemoteAddress
		{
			get { return m_remoteAddress; }
			set { m_remoteAddress = value; }
		}

		/// <summary>
		/// Gets or sets the TCP port number of the remote host or multicast group to which 
		/// the underlying <see cref="UdpClient" /> should sent the logging event.
		/// </summary>
		/// <value>
		/// An integer value in the range <see cref="IPEndPoint.MinPort" /> to <see cref="IPEndPoint.MaxPort" /> 
		/// indicating the TCP port number of the remote host or multicast group to which the logging event 
		/// will be sent.
		/// </value>
		/// <remarks>
		/// The underlying <see cref="UdpClient" /> will send messages to this TCP port number
		/// on the remote host or multicast group.
		/// </remarks>
		/// <exception cref="ArgumentOutOfRangeException">The value specified is less than <see cref="IPEndPoint.MinPort" /> or greater than <see cref="IPEndPoint.MaxPort" />.</exception>
		public int RemotePort
		{
			get { return m_remotePort; }
			set 
			{
				if (value < IPEndPoint.MinPort || value > IPEndPoint.MaxPort) 
				{
					throw log4net.Util.SystemInfo.CreateArgumentOutOfRangeException("value", (object)value,
						"The value specified is less than " + 
						IPEndPoint.MinPort.ToString(NumberFormatInfo.InvariantInfo) + 
						" or greater than " + 
						IPEndPoint.MaxPort.ToString(NumberFormatInfo.InvariantInfo) + ".");
				} 
				else 
				{
					m_remotePort = value;
				}
			}
		}

		/// <summary>
		/// Gets or sets the TCP port number from which the underlying <see cref="UdpClient" /> will communicate.
		/// </summary>
		/// <value>
		/// An integer value in the range <see cref="IPEndPoint.MinPort" /> to <see cref="IPEndPoint.MaxPort" /> 
		/// indicating the TCP port number from which the underlying <see cref="UdpClient" /> will communicate.
		/// </value>
		/// <remarks>
		/// <para>
		/// The underlying <see cref="UdpClient" /> will bind to this port for sending messages.
		/// </para>
		/// <para>
		/// Setting the value to 0 (the default) will cause the udp client not to bind to
		/// a local port.
		/// </para>
		/// </remarks>
		/// <exception cref="ArgumentOutOfRangeException">The value specified is less than <see cref="IPEndPoint.MinPort" /> or greater than <see cref="IPEndPoint.MaxPort" />.</exception>
		public int LocalPort
		{
			get { return m_localPort; }
			set 
			{
				if (value != 0 && (value < IPEndPoint.MinPort || value > IPEndPoint.MaxPort))
				{
					throw log4net.Util.SystemInfo.CreateArgumentOutOfRangeException("value", (object)value,
						"The value specified is less than " + 
						IPEndPoint.MinPort.ToString(NumberFormatInfo.InvariantInfo) + 
						" or greater than " + 
						IPEndPoint.MaxPort.ToString(NumberFormatInfo.InvariantInfo) + ".");
				} 
				else 
				{
					m_localPort = value;
				}
			}
		}