serialization

[reubin haz]

I often see statement: fields declared as transient or static are IGNORED by the deserialization process. But ...

 
import java.io.*;
class AA implements Serializable {
transient int a = 11;
static int b = 22;
 
  public static void main(String[] args) {
 
    AA c1 = new AA ();  
c1.a=33;
b=44;
    try {
      System.out.println("before");
      System.out.println("a is "+c1.a+"  b is "+c1.b);
 
      FileOutputStream fos = new FileOutputStream("aser");
      ObjectOutputStream os = new ObjectOutputStream(fos);
      os.writeObject(c1);
      os.close();
      FileInputStream fis = new FileInputStream("aser");
      ObjectInputStream is = new ObjectInputStream(fis);
      AA c2 = (AA) is.readObject();//2
      System.out.println("after");
      System.out.println("a is "+c2.a+"  b is "+c2.b);
      is.close();
    } catch (Exception x ) { }
  }
}
 

the output is

before
a is 33 b is 44
after
a is 0 b is 44

it seems static variable's value is stored properly. Then why is it saying static is the same behavior as transient ?

[Henry Wong]

I suggest making a small change... prior to deserializing the object back from a file change b to something else. After deserialization, is b the same as when you saved it? or is it the same new value?

Henry

[reubin haz]

I see. Static variable will always keep the current state value.

Thanks Henry