The java.io Package - Serialization

Serialization (JCL1)

• serialization is the process of converting an object to a stream of bytes in such a manner that the original object can be rebuilt (lets you write an object to a file or other data container)
• an object can be serialized only if it's class implements the Serializable or Externalizable interface; it's superclass must have a no-arg default constructor or be Serializable itself
• a classes serializable fields are all of its nontransient and nonstatic fields; this applies to all public, protected, package and private fields (JCL1)

• the serialized fields are written out using ObjectOutputStream.defaultWriteObject() and read back using ObjectOutputStream.defaultReadObject()
• all the objects referred to directly or indirectly are also serialized
• if a field contains an object that is not serializable, a NotSerializableException is thrown

• deserialization is the process of restoring a serialized object to a copy of the original object

• all Java primitive types, arrays, Strings and objects can be serialized/deserialized
• primitive types can be serialized using DataInputStream Interface and deserialized using DataOutputStream Interface