Pop Up a Message at Start Up

To pop a banner which can contain any message you want to display just before a user is going to log on, go to the key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System.

Now create a new string Value in the right pane named LegalNoticeCaption and enter the value that you want to see in the Menu Bar. Now create yet another new string value and name it LegalNoticeText. Modify it and insert the message you want to display each time Windows boots. This can be effectively used to display the company's private policy each time the user logs on to his NT box.

Operators in Jsp

Expression language supports a wide range of operators including arithmetic, relational and logical operators. EL allows you to apply those operators to the literal and variables forcalculations. Here is the list of operators with its alternative version.  

Operator	Alternative	Meaning
[]		Collection member access
·		Property  access
()		Grouping
-		Unary Negation
!	not	Logical not
Empty		Empty test
*		Multiplication
/	div	Division
%	mod	Modulo or division remainder
+		Addition
-		Subtraction
<	lt	Less than
>	gt	Greater than
<=	le	Less than or equal
>=	ge	Greater than or equal
==	eq	Equality
!=	ne	Inequality
&&	and	Logical and
||	or	Logical or
=		Assignment
?:		Conditional operator

Vector in Collections

Vector: - It is a dynamically growing array that stores objects. But it is synchronized. When the object is synchronized then we will get reliable results or values. Vectors are suitable objects.


1. To create a vector
Vector v = new Vector();
Vector v = new Vector (100);


2. To know the size of Vector, use size() method.
int n = v.size();


3. To add elements use add() method.
             v.add(obj);
             v.add(2, obj);


4. To retrieve elements use get() method
                      v.get(2);


5. To remove elements use remove() method
                   v.remove(2);
To remove all elements
                   v.clear();


6. To know the current capacity, use capacity() method
                 int n = v.capacity();


7. To search for last occurrence of an element use indexOf() method
              int n = v . intdexOf(obj);


8. To search for last occurrence of an element use lastIndexOf() method
               int n = v . lastIndexOf(obj);


9. Increases the capacity of this vector, if necessary, to ensure that it can hold at least the number of components specified by the minimum capacity argument.
void ensureCapacity(int minCapacity);


ArrayList is not synchronized by default, but by using some methods we can synchronized the ArrayList.


List myList = Collections.synchronizedList(myList);


Vector is synchronized default.  When we are retreiveing the elements from Vector, it will maintains and gives the same order what we have added the elements to the Vector.  Vector doesn’t supports the null values.


Ex: - //A Vector of int values


import java.util.*;
class VectorDemo
{
public static void main(String args[ ])
{
//Create an empty Vector
Vector v = new Vector ();
//Take (an one dimensional) int type array
int x [ ] = {10, 22, 33, 44, 60, 100};
//Read int values from x and store into v
for(int i = 0; i< x.lenght(); i++)
v.add(new Integer(x[ i ]));
//Retrieve and display the elements
for(int i = 0; i< v.size(); i++)
System.out.println(v.get(i));
//Retrieve elements using ListIterator
ListIterator lit = v. listIterator();
//QIn the above statement ListIterator is an Interface, listIterator() is a method
System.out.println(“In forward direction: ” );
while(lit.hasNext())
System.out.print (lit.next() +“\t”);
System.out.println (“\n In reverse direction: ”);
while(lit.previous())
System.out.print(lit.previous() + “\t”);
}
}