What is Serialization?
In the world of software development, serialization is the process of converting an object into a format that allows it to either be persisted (saved) to disk or memory, or to be transmitted across a network or over HTTP or TCP.
An object that has been serialized can be reconstructed later which is known as deserialization. I like to think of deserialization as the process by which we re-inflate the object back into its original state. If you think of an XML web service as an example, an application can be written using standard .NET objects, serialized as XML, passed around via HTTP or TCP, then deserialized (re-inflated) by the receiving application and used further.
In this article, we are going to take a quick look at three forms of .NET serialization and talk briefly about each. The following three articles will address XML serialization, binary serialization, and SOAP serialization and provide walkthroughs that give you an overview of how to implement each.
Serialization in .NET
The .NET Framework provides a few serialization mechanisms. Let’s discuss the three most well-known:
- XML Serialization – serializes the public fields and properties of an object into an XML stream. XML serialization does not record or preserve information about the object’s original type or namespace. The .NET Framework provides a class called the XmlSerializer. This class provides methods with which we can serialize an deserialize objects.
- Binary Serialization – serializes an object or an entire hierarchy of objects into a binary format. Binary serialization is a very efficient means of serializing .NET objects. The BinaryFormatter class offers numerous methods allow us to serialize and deserialize objects.
- SOAP Serialization – serializes an object into XML, but also serializes private members. SOAP serialization does not support serialization of generic collections, but the SoapFormatter saves assembly and type information along with the data itself. SOAP serialization is ideal for communications between heterogeneous applications, or applications that are written using different architectures, languages, platforms, etc.
The decision as to which type to use is dictated by the needs of the application. For example, XML and SOAP serialization produce XML output which is usable across multiple platforms. Binary serialization in .NET should only be used in situations where the objects to be serialized and deserialized reside in namespaces that are usable and referenced by each application. If there is only one application in the discussion, then binary serialization will provide a speedy, compact form of serialization that will be quite suitable. So it comes down to considering performance, storage type and location, and extensibility.
See the table below for a high-level comparison of these three types of .NET serialization.
To use serialization in .NET, you essentially only need two things:
- A stream to hold or receive the serialized output
- A formatter (XmlSerializer, SoapFormatter, or BinaryFormatter) to fill the stream with output
As we mentioned earlier, XML Serialization utilizes the XmlSerializer class, binary serialization is provided via the BinaryFormatter, and SOAP serialization is handled by the SoapFormatter – .NET provides very rich support for serialization.
.NET Serialization Walkthroughs
The following posts will dive into the specifics of serialization with C# and .NET. Use the links below to select the appropriate post.