public static ReadingState GetInstance()
{
if (s_State == null)
{
s_State = new ReadingState();
}
return(s_State);
}
/// <summary>
/// 执行命令，如果命令是与登录相关则不执行
/// </summary>
/// <returns>如果返回true,则说明命令执行成功</returns>
public override bool IssueCommand(RFC1939.POPCommand command, POPClient context)
{
if (!IsLegalCommand(command))
{
return(false);
}
if (command is RFC1939.QuitCommand)
{
if (command.Execute())
{
context.LoggCommand(command);
context.CurrentState = DisconnectedState.GetInstane();
return(true);
}
context.CurrentState = DisconnectedState.GetInstane();
context.LoggCommand(command);
}
else if (command is RFC1939.RetriveCommand || command is RFC1939.TopCommand)
{
if (command.Execute())
{
context.LoggCommand(command);
context.CurrentState = ReadingState.GetInstance();
return(true);
}
context.LoggCommand(command);
}
else if (command is RFC1939.NoopCommand)
{
if (command.Execute())
{
context.LoggCommand(command);
return(true);
}
else
{
context.LoggCommand(command);
context.Disconnect();
context.CurrentState = DisconnectedState.GetInstane();
}
}
else
{
if (command.Execute())
{
context.LoggCommand(command);
return(true);
}
context.LoggCommand(command);
}
return(false);
}