Roopak Neevan's Blog

Please refer the below artical for the beautiful Explaination :
http://venkatsadasivam.wordpress.com/2008/08/02/why-multiple-inheritance-is-not-allowed-in-java/

Java allows us to create reusable objects in memory. All of those objects exist only as long as the Java virtual machine. With object serialization, we can flatten our objects and reuse them in powerful ways.
 Object serialization is the process of saving an object’s state to a sequence of bytes, and also rebuilding those bytes [...]

What is the difference between Interface and Abstract class or when to use Interfaces and when to use Abstract class ?
Different ppl give different reasons for the same and the major discussions on internet will give the basic differences or I can say the java specifications for this above discussions .
After going thru lot of discussions [...]

public class X{
  public static void main(String [] arg){
     Set s=new TreeSet();
     s.add(new Person(20));
     s.add(new Person(10));
     System.out.println(s);
 }
}
class Person{
    int i;
    Person(int i){
         i = this.i; 
    }
}
Can anyone tell me why this code fragment shows me the “ClassCastException”, Using Java 2 1.5 compiler.
In the above code
Set s=new TreeSet();
Set S which is a TreeSet accepts an object [...]