c# - 接口(interface)和对象反序列化

我有一个定义一个可序列化为字节数组的类的接口(interface)。

public interface IByteSerializable
{
    byte[] GetBytes();
}

一个自然的伙伴是一个反序列化方法，我想返回一个实现IByteSerializable的对象。

我在努力设计这样的界面。

这似乎没有道理:

public interface IByteSerializable
{
    byte[] GetBytes();
    IByteSerializable GetObject(byte[] bytes);
}

因为GetObject()的实现不能是static，并且使用虚拟IByteSerializable对象只是调用GetObject()方法来反序列化我想要的实际对象没有任何意义。

这样做似乎也没有任何意义:

public interface IByteSerializableFactory
{
    IByteSerializable GetObject(byte[] bytes);
}

Factory类可以解决该问题，但是感觉会导致类爆炸。同样，给定的IByteSerializable子类如何序列化和反序列化的细节是相互依赖的，因此将它们保留在同一位置而不是两个不同的类是有意义的。显然，反序列化给定IByteSerializable对象所需的确切过程完全取决于该对象的GetBytes()方法的编写方式。

我可以使用通用的设计或图案来解决此问题吗？

最佳答案

当涉及到您的问题时，关于接口(interface)，类和模式有很多不同的意见。我个人的喜好是使用一个byte []属性实现一个接口(interface)，并使用一个虚方法实现一个抽象类(甚至完全失去该接口(interface)，这可能不是您的选择，并且不能与DI和单元测试一起使用):

public interface IByteSerializable
{
    byte[] SerializableByteObject { get; }
}

public abstract class ByteSerializable : IByteSerializable
{
    public byte[] SerializableByteObject { get; }
    protected virtual byte[] GetBytes() {
        return SerializableByteObject;
    }
    public abstract IByteSerializable GetObject();
    //{    // You can make this method virtual and use Impl method:
           // GetObjectImpl(SerializableByteObject);
    //}
    protected internal IByteSerializable GetObjectImpl(byte[] bytes) {
        // If you need a default implementation (GetObject() should be protected virtual then)
        // return IByteSerializable...;
    }
}

我要强调的是，接口(interface)VS抽象类是一个无休止的讨论。如果您可以在不实现接口(interface)的情况下做一些事情，而只使用抽象类-我强烈建议您这样做。

更新17-3-18 :回复评论(定义行为是界面的目的)并解释我如何看待它，并在下面添加了解释。

在这种情况下，我们定义的“行为”是“一个对象应该可以转换为字节数组。转换结果应该可以转换回相同的对象。”因此，我们实际上是在为对象和字节数组定义行为(因为在对对象进行反序列化之后-它不再是同一对象，而只是一个字节数组)。

从我的角度来看，这是纯粹的工厂模式方案。

// Let's define an interface for our serializable type of objects factory
public interface IByteSerializableFactory<T>
{
     T CreateFromBytes(byte[] objectDataToUse);
     byte[] CovertToBytes(T objectToConvert);
}

// Interface for any class that needs a serialization factory
// This is not even necessary, but I like it to enforce people to implement simple methods that reference the factory.

public interface IByteSerializable<T>
{
    IByteSerializableFactory<T> GetFactory();
}

// Now a moment comes for us to have this kind of class. We need to build a factory first (because our interface requires a GetFactory() implementation. We can lose the IByteSerializable interface altogether, but then we lose a way to let people know which factory should be used.

public class SomeBaseClassSerializationFactory : IByteSerializableFactory<SomeBaseClass>
{
    public SomeBaseClass CreateFromBytes(byte[] objectDataToUse) { //...
        return new SomeClass();
    }
    public byte[] CovertToBytes(SomeBaseClass objectToConvert) { //...
        return new byte[1];
    }
}

// We have a factory, let's implement a class.

public abstract class SomeBaseClass : IByteSerializable<SomeBaseClass>
{
    public virtual IByteSerializableFactory<SomeBaseClass> GetFactory() {
        return new SomeBaseClassSerializationFactory();
    }
}

public class SomeClass : SomeBaseClass {
    // Now we're independent. Our derived classes do not need to implement anything.
    // If the way the derived class is serialized is different - we simply override the method
}

更新2年3月18日:在其他答案下答复评论(通用实现，只需使用界面即可)。

不幸的是，没有干净的方法可以做到这一点。通过使用一些作弊，定义定义序列化方法的类以及使用反射来返回正确的类型，这是一种肮脏的方式(我个人认为:“BAD BAD BAD!”)。下面的示例将在序列化方法中使用大量自定义逻辑，以使用不同类型的正确字段:

// You define an enum with action and a dictionary with a collection of serialization methods.
public enum SerializationAction {
    ToBytes,
    ToObject
}

// It can also be an enum, but it's easier to test with a collection of strings.
public static readonly string[] SerializationKindList = new string[] {
    "FirstKind",
    "SecondKind"
};

// This generic class can have an implementation of all the handlers. Additional switching can be done by type, or reflection can be used to find properties for different classes and construct different classes.
public class SerializationMethod {
    public object ProcessByKind (string kindToUse, SerializationAction action, object objectToProcess) {
        if (kindToUse == "FirstKind") {
            if (action == SerializationAction.ToBytes) {
                return new byte[1];
            }

            return new SomeClass(); // These would need to be your hard implementations. Not clean.
        } else {
            throw new NotImplementedException();
        }
    }
}

// This struct type defines the serialization method and is required for the interface implementation
public struct ByteSerialization
{
    public string SerializationTypeName { get; private set; }
    public ByteSerialization(string kindToUse) {
        if (!SerializationKindList.Contains(kindToUse)) {
            throw new ArgumentException();
        }

        SerializationTypeName = kindToUse;
    }
    public byte[] Deserialize(object objectToProcess) {
        var serializationMethod = new SerializationMethod();
        return (byte[])serializationMethod.ProcessByKind(this.SerializationTypeName, SerializationAction.ToBytes, objectToProcess);
    }
    public object Serialize(byte[] byteArrayToProcess) {
        var serializationMethod = new SerializationMethod();
        return serializationMethod.ProcessByKind(this.SerializationTypeName, SerializationAction.ToObject, byteArrayToProcess);
    }
}


// Interface for any class that needs to use generic serialization
public interface IByteSerializable
{
    ByteSerialization serializationType { get; }
}

// Creating extension methods for the interface to make the life easier
public static class IByteSerializableExtensions {
    public static byte[] DeserializeObjectIntoBytes(this IByteSerializable objectToProcess) {
        return objectToProcess.serializationType.Deserialize(objectToProcess);
    }
    public static void SerializeObjectFromBytes(this IByteSerializable objectToProcess, byte[] fromBytes) {
        var someObjectData = objectToProcess.serializationType.Serialize(fromBytes);
    }
}


// Abstract base class implementation with static readonly field.
// Only downside - there is no way to enforce the config of this field in the constructor from the interface.
// There also no way to make sure this field always gets set for other implementations of IByteSerializable
public abstract class SomeBaseClass : IByteSerializable
{
    private static readonly ByteSerialization _serializationType = new ByteSerialization("FirstKind");

    public ByteSerialization serializationType { get { return _serializationType; } }
}

public class SomeClass : SomeBaseClass {

}


// And here's how one would use it. You will need to create a new object of the class before serializing from bytes.
var someClass = new SomeClass();
var bytes = someClass.DeserializeObjectIntoBytes();
var someClass2 = new SomeClass();
var byteArray = new byte[1];
someClass2.SerializeObjectFromBytes(byteArray);

关于c# - 接口(interface)和对象反序列化，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/42870501/