In Java (and many other programming languages), serialization and deserialization are techniques used to convert objects into a format that can be easily saved or transferred—and then later restored.
📦 Serialization
Serialization is the process of converting a Java object into a stream of bytes. This is useful when you want to:
- Save an object to a file
- Send an object over a network
- Store an object in a database
Once it’s serialized, it can be stored or transferred easily.
ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("data.ser"));
out.writeObject(myObject); // Converts the object to bytes
out.close();⚠️ The class must implement Serializable to be eligible for serialization:
class MyData implements Serializable { int id; String name; }
💾 Deserialization
Deserialization is the reverse—it reconstructs the object from its byte-stream form.
ObjectInputStream in = new ObjectInputStream(new FileInputStream("data.ser")); MyData obj = (MyData) in.readObject(); // Recreates the object
in.close();🛡 Pro Tip: If a class changes (e.g., new fields are added) after serialization, you may get compatibility issues. That’s where a serialVersionUID can help maintain version control.
