学步园

一、摘要

场景： 

      最近公司的项目中用到了WCF 就想着分析OEA里的WCF设计，吸取一下高手的经验 。

类图：

       今天在这里主要是分析OEA里的WCF设计(也叫分布式业务对象数据门户)。先看一下OEA类库

      

二、本文大纲

       a、摘要 。

       b、本文大纲 。

       c、WCF接口设计。

       d、WCF 交互设计 。

       e、数据门户设计 。

       f、业务对象知识补充 。

三、WCF接口设计

关于WCF接口的相关知识可以看以前写WCF 开发日志 -- WCF契约设计

 

消息契约(MessageContract)  在 WCF 开发日志 -- WCF契约设计 有提到一点，在网上和MSDN上有更详细的说明了，这里就不详细描述了。

WcfResponse , FetchRequest , UpdateRequest 

上面类图对应有三个文件，其实这三个文件的内容都差不多，只是职责不同。

 

四、WCF 交互设计

服务端实现：

 红色部分就是WCF适配到数据门户来进行与数据库交互否实现业务逻辑。

 1:  /// <summary>

 2:    /// 使1用?WCF实现的统一的数据门户

 3:    /// 

 4:    /// 标记了ConcurrencyMode.Multiple 来表示多线程进行

 5:    /// </summary>

 6:    [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall, ConcurrencyMode = ConcurrencyMode.Multiple, UseSynchronizationContext = false)]

 7:    [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]

 8:    public class WcfPortal : IWcfPortal

 9:    {

10:        /// <summary>

11:        /// Get an existing business object.

12:        /// </summary>

13:        /// <param name="request">The request parameter object.</param>

14:        public WcfResponse Fetch(FetchRequest request)

15:        {

16:            OEA.Server.DataPortalFacade portal = new OEA.Server.DataPortalFacade();

17:            object result;

18:            try

19:            {

20:                result = portal.Fetch(request.ObjectType, request.Criteria, request.Context);

21:            }

22:            catch (Exception ex)

23:            {

24:                result = ex;

25:            }

26:            return new WcfResponse(result);

27:        }

28:   

29:        /// <summary>

30:        /// Update a business object.

31:        /// </summary>

32:        /// <param name="request">The request parameter object.</param>

33:        public WcfResponse Update(UpdateRequest request)

34:        {

35:            OEA.Server.DataPortalFacade portal = new OEA.Server.DataPortalFacade();

36:            object result;

37:            try

38:            {

39:                result = portal.Update(request.Object, request.Context);

40:            }

41:            catch (Exception ex)

42:            {

43:                result = ex;

44:            }

45:            return new WcfResponse(result);

46:        }

47:    }

48:   

 

客服端直接使用WCF的代理类ChannelFactory实现

  1:  /// <summary>
  2:      /// Implements a data portal proxy to relay data portal
  3:      /// calls to a remote application server by using WCF.
  4:      /// </summary>
  5:      public class WcfProxy : OEA.DataPortalClient.IDataPortalProxy，IDataPortalServer
  6:      {
  7:          #region IDataPortalProxy Members
  8:   
  9:          /// <summary>
 10:          /// Gets a value indicating whether the data portal
 11:          /// is hosted on a remote server.
 12:          /// </summary>
 13:          public bool IsServerRemote
 14:          {
 15:              get { return true; }
 16:          }
 17:   
 18:          #endregion
 19:  
 20:          #region IDataPortalServer Members
 21:   
 22:          private string _endPoint = "WcfDataPortal";
 23:   
 24:          /// <summary>
 25:          /// Gets or sets the WCF endpoint used
 26:          /// to contact the server.
 27:          /// </summary>
 28:          /// <remarks>
 29:          /// The default value is WcfDataPortal.
 30:          /// </remarks>
 31:          protected string EndPoint
 32:          {
 33:              get
 34:              {
 35:                  return _endPoint;
 36:              }
 37:              set
 38:              {
 39:                  _endPoint = value;
 40:              }
 41:          }
 42:   
 43:          /// <summary>
 44:          /// Returns an instance of the channel factory
 45:          /// used by GetProxy() to create the WCF proxy
 46:          /// object.
 47:          /// </summary>
 48:          protected virtual ChannelFactory<IWcfPortal> GetChannelFactory()
 49:          {
 50:              return new ChannelFactory<IWcfPortal>(_endPoint);
 51:          }
 52:   
 53:          /// <summary>
 54:          /// Returns the WCF proxy object used for
 55:          /// communication with the data portal
 56:          /// server.
 57:          /// </summary>
 58:          /// <param name="cf">
 59:          /// The ChannelFactory created by GetChannelFactory().
 60:          /// </param>
 61:          protected virtual IWcfPortal GetProxy(ChannelFactory<IWcfPortal> cf)
 62:          {
 63:              return cf.CreateChannel();
 64:          }
 65:   
 66:          /// <summary>
 67:          /// Called by <see cref="DataPortal" /> to load an
 68:          /// existing business object.
 69:          /// </summary>
 70:          /// <param name="objectType">Type of business object to create.</param>
 71:          /// <param name="criteria">Criteria object describing business object.</param>
 72:          /// <param name="context">
 73:          /// <see cref="Server.DataPortalContext" /> object passed to the server.
 74:          /// </param>
 75:          public DataPortalResult Fetch(Type objectType, object criteria, DataPortalContext context)
 76:          {
 77:              ChannelFactory<IWcfPortal> cf = GetChannelFactory();
 78:              IWcfPortal svr = GetProxy(cf);
 79:              WcfResponse response = null;
 80:              try
 81:              {
 82:                  response =
 83:                         svr.Fetch(new FetchRequest(objectType, criteria, context));
 84:                  if (cf != null)
 85:                      cf.Close();
 86:              }
 87:              catch
 88:              {
 89:                  cf.Abort();
 90:                  throw;
 91:              }
 92:   
 93:              object result = response.Result;
 94:              if (result is Exception)
 95:                  throw (Exception)result;
 96:              return (DataPortalResult)result;
 97:          }
 98:   
 99:          /// <summary>
100:          /// Called by <see cref="DataPortal" /> to update a
101:          /// business object.