Sandeep Reddy Vinta

HI,
Is there any utility class in java which helps in computing Permutation and Combination?

Thanks Rob for your reply. I'll definitely take your suggestions.

I want to check whether i understood the behavior of the code properly.


In the above code i have posted.


Serialization Process.

Will not store the static information.


Desirialization Process.

Will get the static field information by loading the class. As the class ABC is already
loaded into the JVM, it refers to the static field which is already existing in the memory.
As it is changed in the constructor, the deserialization would pick the changed one from the memory.



Is this understanding proper.

Guys Even i'm interested in taking scjp1.6 ...Please feel free to sell you voucher to me ...But how much it costs in prometric centers...

I read java serialization doesn't include static variable's data. But when i run the following java file it does. It retains the value of the static variable. Can anyone explain why

Code
package com.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; public class SerTest { public static void main(String[] args) { ABC a = new ABC(); try { ObjectOutputStream os = new ObjectOutputStream(new FileOutputStream("serialization.ser")); os.writeObject(a); os.close(); System.out.println("Before Serialization :" + a.toString()); ObjectInputStream is = new ObjectInputStream(new FileInputStream("serialization.ser")); ABC aNew = (ABC) is.readObject(); is.close(); System.out.println("ABCfter Serialization :" + aNew.toString()); } catch (FileNotFoundException e) { // TODO ABCuto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO ABCuto-generated catch block e.printStackTrace(); } catch (ClassNotFoundException e) { // TODO ABCuto-generated catch block e.printStackTrace(); } } } class ABC implements Serializable{ static int y = 9; transient int x = 8; public ABC() { y = 20; } @Override public String toString() { return "x : " + x + ", y :" + y; } }
Output :


Before Serialization :x : 8, y :20
ABCfter Serialization :x : 0, y :20



If you observe the static variable y before serialization is initialized to 9 and later changed to 20 in constructor. After serialization is done. Now Deserializing the class shouldn't retain the static variable content according to my assumption : "java serialization doesn't include static variable's data". Why is this happening.