#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.Net;
namespace log4net.Util.TypeConverters
{
///
/// Supports conversion from string to type.
///
///
///
/// Supports conversion from string to type.
///
///
///
///
/// Nicko Cadell
internal class IPAddressConverter : IConvertFrom
{
#region Implementation of IConvertFrom
///
/// Can the source type be converted to the type supported by this object
///
/// the type to convert
/// true if the conversion is possible
///
///
/// Returns true if the is
/// the type.
///
///
public bool CanConvertFrom(Type sourceType)
{
return (sourceType == typeof(string));
}
///
/// Overrides the ConvertFrom method of IConvertFrom.
///
/// the object to convert to an IPAddress
/// the IPAddress
///
///
/// Uses the method to convert the
/// argument to an .
/// If that fails then the string is resolved as a DNS hostname.
///
///
///
/// The object cannot be converted to the
/// target type. To check for this condition use the
/// method.
///
public object ConvertFrom(object source)
{
string str = source as string;
if (str != null && str.Length > 0)
{
try
{
// Check if the string only contains IP address valid chars
if (str.Trim(validIpAddressChars).Length == 0)
{
try
{
// try to parse the string as an IP address
return IPAddress.Parse(str);
}
catch(FormatException)
{
// Ignore a FormatException, try to resolve via DNS
}
}
// Try to resolve via DNS. This is a blocking call.
IPHostEntry host = Dns.GetHostByName(str);
if (host != null &&
host.AddressList != null &&
host.AddressList.Length > 0 &&
host.AddressList[0] != null)
{
return host.AddressList[0];
}
}
catch(Exception ex)
{
throw ConversionNotSupportedException.Create(typeof(IPAddress), source, ex);
}
}
throw ConversionNotSupportedException.Create(typeof(IPAddress), source);
}
#endregion
///
/// Valid characters in an IPv4 or IPv6 address string. (Does not support subnets)
///
private static readonly char[] validIpAddressChars = {'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f','A','B','C','D','E','F','x','X','.',':','%'};
}
}