【翻译】Serialization / Marshalling / Deflating in JAVA

原文地址： http://www.dzone.com/links/r/serialization_marshalling_deflating_in_java.html

Writing Java Objects or keeping the state of Objects into DataBase or Files (In Binary Format) is known as Serialization or Marshalling or deflating.
Reading Java Objects back in Binary Format from file or Database is known as DeSerialization or UnMarshalling or inflating.



Transient : If any variable is defined by using keyword “transient”, then object will not serialize that variable. During deserialization default value of that datatype will be set.
Static : as static variables are class level variables, so it is not serialzed as the object state.

Example:

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package com.G2.Serialization;
 
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
 
class Home implements Serializable
{
     transient int flatNo;
     String OwnerName;
}
 
class Door extends Home
{
    private boolean isDoubleLock;
    private String DoorMaterial;
    public void setValue(boolean isDLock,String dMaterial, int fNo,String Owner)
    {
        isDoubleLock = isDLock;
        DoorMaterial = dMaterial;
        flatNo = fNo;
        OwnerName = Owner;
    }
    public void Display()
    {
        System.out.println("Double Lock - "+isDoubleLock);
        System.out.println("Material - "+DoorMaterial);
        System.out.println("flat No - "+flatNo);
        System.out.println("Owner Name - "+OwnerName);
    }
}
 
public class SerializationDemo {
    public static void main(String[] args) throws FileNotFoundException, IOException,
ClassNotFoundException {
        ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("Demo.srl"));
 
        Door d = new Door();
        d.setValue(true, "Wood", 24, "Minal Zaa");
        System.out.println(" *** Serializing Object *** ");
        out.writeObject(d);
 
        out.close();
 
        ObjectInputStream in = new ObjectInputStream(new FileInputStream("Demo.srl"));
        System.out.println(" *** DeSerializing Object *** ");
        Door d1 = (Door) in.readObject();
        d1.Display();
 
        in.close();
 
    }
}

Output:

    *** Serializing Object ***

    *** DeSerializing Object ***
    Double Lock – true
    Material – Wood
    flat No – 0
    Owner Name – Minal Zaa

Note from example:
Parent class implements interface “Serializable” and child class extends that, so child class automatically gets serialized.
Variable “flatNo” is transient and therefore it is not serialized.