An Externalizable class is one which handles its own Serialization and deserialization. During deserialization, the first
step in the process is a default instantiation using the class' no-argument constructor. Therefore an Externalizable class without a
no-arg constructor cannot be deserialized.
public class Tomato implements Externalizable { // Noncompliant; no no-arg constructor
public Tomato (String color, int weight) { ... }
}
public class Tomato implements Externalizable {
public Tomato() { ... }
public Tomato (String color, int weight) { ... }
}