Unity3D自学笔记——Photon服务器的后台架构实现（三）

ALI.ARPG.CommandProcessor





ICommand

命令接口，该接口为空接口，没有包含任何函数，只作为约束

public interface ICommand
{

}

ICommandHandler

命令角色，通过调用Data层实现具体的业务逻辑处理，这里用了TCommand泛型而没直接用ICommand，是为了后面CommandBus反射去找ICommand对应的Handler

public interface ICommandHandler<in TCommand> where TCommand : ICommand
{
ICommandResult Excute(TCommand command);
}

ICommandResult

ICommandHandler执行处理的结果

public interface ICommandResult
{
bool Success { get; }
}

public class CommandResult : ICommandResult
{
public CommandResult(bool success)
{
this.Success = success;
}

public bool Success { get; protected set; }
}

IValidateHandler

同样为命令角色，命令执行前验证，如用户注册前需要验证用户名合法性，验证结果为IEnumerable，意味可以有多种验证错误，如长度不符合，字符非法等，返回null，则表示验证通过

public interface IValidateHandler<in TCommand> where TCommand : ICommand
{
IEnumerable<ValidationResult> Validate(TCommand command);
}

ValidationResult

验证结果，这里没用接口是因为其没有具体方法，只是一个单纯的对象

public class ValidationResult
{
public string MemberName { get; set; }
public string Message { get; set; }
public ValidationResult()
{
}

public ValidationResult(string memberName, string message)
{
this.MemberName = memberName;
this.Message = message;
}

public ValidationResult(string message)
{
this.Message = message;
}
}

ICommandBus

命令接收者，接收命令，并移交至相应的Handler进行处理。

public interface ICommandBus
{
ICommandResult Submit<TCommand>(TCommand command) where TCommand : ICommand;
IEnumerable<ValidationResult> Validate<TCommand>(TCommand command) where TCommand : ICommand;
}

CommandBus

通过反射查找对应的CommandHandler和ValidateHandler，具体实现方法为GetHandlerType

1. 遍历ALI.ARPG.DOMAIN里的所有类型

2. 查找是否有实现了TCommand对应ICommandHandler、IValidateHandler接口的类

*如

TCommad为 RegCommand : ICommand

对应的ICommandHandler 即为 ICommandHandler< RegCommand>，则遍历查找是否有类实现了该接口*

3. 反射创建该类

4. 此处应该有缓存

public class CommandBus : ICommandBus
{
public ICommandResult Submit<TCommand>(TCommand command) where TCommand : ICommand
{
var handler = GetCommandHandler(command);
if (!((handler != null) && handler is ICommandHandler<TCommand>))
{
throw new CommandHandlerNotFoundException(typeof(TCommand));
}
return handler.Excute(command);
}

public IEnumerable<ValidationResult> Validate<TCommand>(TCommand command) where TCommand : ICommand
{
var handler = GetValidateHandler(command);
if (!((handler != null) && handler is IValidateHandler<TCommand>))
{
throw new ValidationHandlerNotFoundException(typeof(TCommand));
}
return handler.Validate(command);
}

private ICommandHandler<TCommand> GetCommandHandler<TCommand>(TCommand command) where TCommand : ICommand
{
Object handler = GetHandlerType(command, typeof(ICommandHandler<>));
if (handler != null)
return handler as ICommandHandler<TCommand>;
return null;
}

private IValidateHandler<TCommand> GetValidateHandler<TCommand>(TCommand command) where TCommand : ICommand
{
Object handler = GetHandlerType(command, typeof(IValidateHandler<>));
if (handler != null)
return handler as IValidateHandler<TCommand>;
return null;
}

private Object GetHandlerType<TCommand>(TCommand command, Type handlerType)
{
Assembly assmbly = Assembly.Load("ALI.ARPG.DOMAIN");
Type[] types = assmbly.GetTypes();
Type commandType = command.GetType();
handlerType = handlerType.MakeGenericType(commandType);

foreach (var type in types)
{
if (type.GetInterfaces().Length > 0 && (type.GetInterfaces()[0].Equals(handlerType)))
{
var handler = Activator.CreateInstance(type);
return handler;
}
}

return null;
}
}