XML - Deserialization

What Deserialization Is

• Serialization = convert an object → XML (or another format).

• Deserialization = the reverse: convert XML → object in memory.

• It allows programs to reconstruct data structures from XML text.

Why It’s Useful

• Data can be stored or transmitted as XML, then recreated as objects in another program or on another system.

• Common in:

  • Web services / APIs (XML responses mapped to objects).

  • Config files (load settings into objects).

  • Data exchange between different platforms.

Example (C# style)

XML file:

<Book>
  <Title>XML Guide</Title>
  <Author>A. Smith</Author>
</Book>

Class:

public class Book {
    public string Title { get; set; }
    public string Author { get; set; }
}

Deserialization code:

XmlSerializer serializer = new XmlSerializer(typeof(Book));
using (FileStream fs = new FileStream("book.xml", FileMode.Open)) {
    Book b = (Book)serializer.Deserialize(fs);
}

Now b.Title = "XML Guide", b.Author = "A. Smith".

Deserialization vs Parsing

• Parsing: just reading XML structure (like SAX, DOM, StAX).

• Deserialization: goes further — it maps XML elements directly to object fields/properties.

Advantages

• Easy way to reconstruct complex objects.

• Automates data binding between XML and code.

Disadvantages

• Requires schema/class definition.

• Sensitive to mismatches between XML structure and object structure.

In short:
Deserialization = taking XML text and rebuilding it into program objects, making XML data usable directly in code.