in Java Serialization concept. In an already serialized object, the most challenging task is to change the structure of a class when a new field is added or removed. As per the specifications of Java Serialization, addition of any method or field is considered to be a compatible change whereas changing of class hierarchy or non-implementation of Serializable interface is considered to be a non-compatible change. You can go through the Java serialization specification for the extensive list of compatible and non-compatible changes. If a serialized object need to be compatible with an older version, it is necessary that the newer version follows some rules for compatible and incompatible changes. A compatible change to the implementing class is one that can be applied to a new version of the class, which still keeps the object stream compatible with older version of same class. Some Simple Examples of compatible changes are: Addition of a new field or class will not affect serialization, since any new data in the stream is simply ignored by older versions. the newly added field will be set to its default values when the object of an older version of the class is un marshaled. The access modifiers change (like private, public, protected or default) is compatible since they are not reflected in the serialized object stream. Changing a transient field to a non-transient field is compatible change since it is similar to adding a field. Changing a static field to a non-static field is compatible change since it is also similar to adding a field.
Java
Topic: Serialization
What changes are compatible and incompatible to the mechanism of java Serialization?
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