XMLDecoder

XMLDecoder is a Java class found in the java.beans package. It is used for deserializing XML data into Java objects. This process is the reverse of encoding, where Java objects are written into XML format using an XMLEncoder. XMLDecoder reads XML, typically generated by an XMLEncoder, and reconstructs the corresponding Java objects based on the XML structure and the object's class information.

The primary use case for XMLDecoder is to persist and later restore the state of Java objects. This can be useful for application configuration, saving user preferences, or transferring object data. The XML format produced by XMLEncoder is human-readable, making it convenient for debugging and manual inspection. XMLDecoder relies on the Java Bean conventions, meaning that the objects it decodes should have appropriate getter and setter methods and a public no-argument constructor.

When decoding, XMLDecoder parses the XML document, identifies the target object type, and uses reflection to create an instance of that object. It then populates the object's properties by reading the corresponding elements and attributes from the XML. The deserialization process can handle complex object graphs, including collections and nested objects, as long as they are properly represented in the XML. It's important to note that security considerations are paramount when using XMLDecoder, especially with untrusted XML sources, as it can potentially execute arbitrary code during deserialization.