大 家好，今天有时间来介绍一下Lind.DDD框架里的消息机制，消息发送这块一般的实现方法是将Email,SMS等集成到一个公用类库里，而本身 Email和SMS没什么关系，它们也不会有什么接口约定，即你想实现某种消息的多态发送，不需要程序代码，基本不可能实现，而在Lind.DDD里面， 大叔将它进行了抽象，消息有自己的统一接口，而对于email和sms只是一种实现而以，这样，就可以发挥面向对象的特性，在sms,email甚至是 rtx上进行消息的灵活切换了，说到这样，您心动了吧！
Lind.DDD.Messaging框架图
接口规范
/// <summary>
/// Message Interface
/// Author:Garrett
/// </summary>
public interface IMessageManager
{
/// <summary>
/// Sends a message to a channel using a content item as the recipient
/// </summary>
/// <param name="recipient">接收者</param>
/// <param name="subject">主题</param>
/// <param name="body">消息主体</param>
/// <param name="serverVirtualPath">本参数可以没有，服务端模块级路径，只在xmpp中有意义</param>
void Send(string recipient, string subject, string body, string serverVirtualPath = null);
/// <summary>
/// Sends a message to a channel using a set of content items as the recipients
/// </summary>
/// <param name="recipients">A set of content items to send the message to. Only one message may be sent if the channel manages it.</param>
/// <param name="type">A custom string specifying what type of message is sent. Used in even handlers to define the message.</param>
/// <param name="service">The name of the channel to use, e.g. "email"</param>
/// <param name="properties">A set of specific properties for the channel.</param>
void Send(IEnumerable<string> recipients, string subject, string body, string serverVirtualPath = null);
/// <summary>
/// Async Sends a message to a channel using a set of content items as the recipients
/// </summary>
/// <param name="recipients">A set of content items to send the message to. Only one message may be sent if the channel manages it.</param>
/// <param name="type">A custom string specifying what type of message is sent. Used in even handlers to define the message.</param>
/// <param name="service">The name of the channel to use, e.g. "email"</param>
/// <param name="properties">A set of specific properties for the channel.</param>
/// <param name="isAsync">is Async</param>
void Send(IEnumerable<string> recipients, string subject, string body, bool isAsync, string serverVirtualPath = null);
}
从接口定义上，我们看到了异步的影子，大叔把异步这块写在了参数上，当然，一般情况来说，消息应该都是异步的。
消息上下文
/// <summary>
/// 消息实体
/// </summary>
public class MessageContext
{
/// <summary>
/// 消息类型
/// </summary>
public MessageType Type { get; set; }
/// <summary>
/// 消息头
/// </summary>
public string Subject { get; set; }
/// <summary>
/// 消息正文
/// </summary>
public string Body { get; set; }
/// <summary>
/// 接受方地址列表
/// </summary>
public IEnumerable<string> Addresses { get; set; }
/// <summary>
/// 是否处于准备发送状态
/// </summary>
public bool MessagePrepared { get; set; }
public MessageContext()
{
Addresses = Enumerable.Empty<string>();//这时Addresses!=null,使用Addresses.ToList().ForEach(i => Console.WriteLine(i));不会引发异常
}
}
消息上下文就是消息的对象，类型于EF里的DataContext数据上下文或者HttpContext上下文，都是指实现某些功能的数据对象
消息生产者
/// <summary>
/// 消息生产者
/// 具体消息生产者是单例，如Email,SMS,Rtx等
/// </summary>
public sealed class MessageFactory
{
/// <summary>
/// 消息工厂
/// </summary>
public static IMessageManager GetService(MessageType messageType)
{
switch (messageType)
{
case MessageType.Email:
return EmailMessageManager.Instance;
case MessageType.SMS:
return SMSMessageManager.Instance;
case MessageType.RTX:
return RTXMessageManager.Instance;
case MessageType.XMPP:
return XMPPMessageManager.Instance;
default:
throw new NotImplementedException("消息生产者未被识别...");
}
}
}
从生产者代码上可以看出，在一个领域项目里，你可以通过GetService来使用不同的消息，这是对象的，这前大叔的设计存在一些局限性，一个项目只能用一种消息机制，这对于项目来说，是不能满足了，所以，大叔在Lind.DDD框架里对它进行了改善！
Email实现者
/// <summary>
///Email消息服务
/// </summary>
internal class EmailMessageManager : IMessageManager
{
#region Singleton
private static object lockObj = new object();
public static EmailMessageManager Instance;
static string email_Address = ConfigurationManager.AppSettings["Email_Address"];
static string email_DisplayName = ConfigurationManager.AppSettings["Email_DisplayName"];
static string email_Host = ConfigurationManager.AppSettings["Email_Host"];
static string email_Password = ConfigurationManager.AppSettings["Email_Password"];
static int email_Port = Convert.ToInt32(ConfigurationManager.AppSettings["Email_Port"] ?? "21");
static string email_UserName = ConfigurationManager.AppSettings["Email_UserName"];
static EmailMessageManager()
{
lock (lockObj)
{
if (Instance == null)
Instance = new EmailMessageManager();
}
}
private EmailMessageManager()
{ }
#endregion
#region IMessageManager 成员
public void Send(string recipient, string subject, string body, string serverVirtualPath = null)
{
Send(new List<string> { recipient }, subject, body);
}
public void Send(IEnumerable<string> recipients, string subject, string body, string serverVirtualPath = null)
{
Send(recipients, subject, body, false);
}
public void Send(IEnumerable<string> recipients, string subject, string body, bool isAsync, string serverVirtualPath = null)
{
try
{
if (recipients != null && recipients.Any())
{
using (SmtpClient client = new SmtpClient()
{
Host = email_Host,
Port = email_Port,
Credentials = new NetworkCredential(email_UserName, email_Password),
EnableSsl = false,//设置为true会出现"服务器不支持安全连接的错误"
DeliveryMethod = SmtpDeliveryMethod.Network,
})
{
#region Send Message
var mail = new MailMessage
{
From = new MailAddress(email_Address, email_DisplayName),
Subject = subject,
Body = body,
IsBodyHtml = true,
};
MailAddressCollection mailAddressCollection = new MailAddressCollection();
recipients.ToList().ForEach(i =>
{
//email有效性验证
if (new Regex(@"^([w-.]+)@(([[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.)|(([w-]+.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(]?)$").IsMatch(i))
mail.To.Add(i);
});
if (isAsync)
{
client.SendCompleted += new SendCompletedEventHandler(client_SendCompleted);
client.SendAsync(mail, recipients);
}
else
{
client.Send(mail);
}
#endregion
}
}
}
catch (Exception ex)
{
LoggerFactory.Instance.Logger_Info(ex.Message);
}
}
void client_SendCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
{
string arr = null;
(e.UserState as List<string>).ToList().ForEach(i => { arr += i; });
//发送完成后要做的事件，可能是写日志
}
#endregion
}
通过代码可以看它自已是个internal的，即对外不公开，对外只能通过消息生成者进行访问，它与SMS，RTX形成了一种策略模式的概念。
SMS实现者，请看Lind.DDD源码
RTX实现者，请看Lind.DDD源码
XMPP实现者，请看Lind.DDD源码