Java object serialization and java serialization

Java object serialization and java serialization

Java provides two methods for Object Persistence: serialization and external serialization.

(1) Serialization

Serialization is a process that describes an object in a string of bytes. It is used to solve the problems caused by read/write operations on the object stream.

All classes to be serialized must implement the serializable interface.

(2) External serialization (externalizable)

To implement external serialization, you must implement the readExternal (ObjectInput in) and writeExternal (ObjectOutput out) methods.

Serialization features:

1. If a class can be serialized, its subclass can also be serialized.

2. Because static modified variables or methods represent class members and transient keyword modified variables represent temporary data of objects, it is not enough to declare these two types of data members to be serialized.

When to use serialization?

1. The status of the object or object to be sent over the network needs to be persisted to the database or file.

2. serialization can achieve deep replication.