CTRL + ALT + DEL is out, CTRL + SHIFT + ESC is the new IN thing

Sick of watching the Windows User options screen when pressing the famous CTRL + ALT + DEL combination?

Ever wondered why can’t the old three-finger shuffle directly bring up the task manager in vista or Windows 7 like it did in XP?

Thats because CTRL+ALT+DEL no longer brings up the task manager in vista. But that does not mean that there is no shortcut to directly bring up the task manager.

Since vista is build in line with NT, this has been changed to the NT behavior.

The new keyboard combination to bring up the task manager is:

CTRL+SHIFT+ESC

This even works with Windows XP and Windows 7 apart from Vista. Guess its time to practice this new combination and spread the word.

Deccan Chargers pulverize the Delhi Daredevils in IPL 2 Semifinals

Hi guys,

I am back and am sure the Deccan chargers followers are gonna enjoy this post of mine, with Chargers and Royal Challengers both entering into the semi finals I finally started watching the whole match instead of checking the scores in between the overs; and boy am I glad I did.

With the first semi final placed between Deccan Chargers (my fav team) and DareDevils (the team I hate the most), I just wanted the chargers to charge on their batteries and shoo away the Darpok(coward)Devils.

               v/s

The first half of the match wasn't quite as I had imagined it to be (but still the 2 wickets at the end of first over was enough to bring a cheer on my face) and the chargers got a target of 154 to chase.

With Adam Gilchrist and Gibbs on the field, I was looking forward to some action and I wasn't disappointed thanks to Gilchrist who slammed 21 runs in the 1st over with 5 boundaries, and that was just the beginning. He banged every bowler (NO PUN INTENDED :D) and every ball for a boundary scoring a 50 in just 17 balls (and also scoring respect in many people's hearts).


Adam Gilchrist - The juggernaut

I was extremely elated at the sight of consecutive boundaries and specially so to see the expressions at all the Darpok Devils team member's faces, they all had 12 struck on them.

Gilchrist got out at 85, leaving an easy target for the rest of the team members. Symonds jumped in and whacked another 24 runs before getting caught.

Finally the winning single was taken by Rohit Sharma, who certainly seemed different from his explosive type.

Today's match was one which certainly none of the chargers fan should have missed, watching Gilchrist thrashing every bowler for a boundary was a treat, even the darpok devil's captain wasn't spared, not to mention the bowling figures of Nannes :D.

Now I am looking forward to watching the finals, not to mention how happy I am to watch the darpok devils getting kicked out of the finals and just can't wait to put the lids on a certain someone's mouth who THINKS he is the biggest fan of Darpok devils.

Lazy Coder signing off for now.....

PS: Expect another post if Chargers win IPL 2

hashCode and equals Methods in java classes

Often while working with objects, we want to compare whether the objects we are working with are unique or equal to each other, java has provided us with two methods in java.lang.Object and by overriding them we can compare two objects. These methods are :

1. equals method indicates whether some other object is "equal to" this one.

2. hashCode method returns a hash code value for the object, which is unique for unequal objects.

The equals method and hashCode method for any java class should go hand in hand. Any variable contributing to equals method must also be used for hashCode calculation because as per definition Objects having same hashCode should be equal to each other or conversely no two different objects may have the same hashCode.

hashCode values may also be inserted into the database as passwords and when user enters password in the application, its hashCode can be compared with the value in password field. Thus hashCode can also help with data encryption.

Here is an example on how to implement these methods.

/*

  *   @(#)Employee.java       1.1   11/05/09

  *

  *   Copyright   2009   Lazy   Coder.   All   rights   reserved.

  *   To   be   used   only   for   educational   purposes.

  *   Not   to   be   reproduced   and   published

  *   without   seeking   prior   consent.

  */

package   com.lazy.coder.examples;



/**

  *  

  *   @author   lazycoder

  *

  */



public   class   Employee   {

       private   int   empId;

       private   String   empName;



       public   boolean   equals(Object   obj)   {

              //If   this   object   and   the   Object   in   the   argument   refer   to   same   object   return   true.

              if   (this   ==   obj)

                     return   true;

              //If   obj   is   null   or   of   some   other   class   return   false.

              if   ((obj   ==   null)   ||   (obj.getClass()   !=   this.getClass()))

                     return   false;

              //   object   must   be   of   type   Employee   now

              Employee   emp   =   (Employee)   obj;

              //If   empId   =   obj.emoId   and   empName.equals(obj.empName)   return   true   else   false.

              return   empId   ==   emp.empId

                            &&   (empName   ==   emp.empName   ||   (empName   !=   null   &&   empName

                                          .equals(emp.empName)));

       }



       public   int   hashCode()   {

              int   result   =   17;

              result   =   37   *   result   +   empId;

              result   =   37   *   result   +   (empName   ==   null   ?   0   :   empName.hashCode());

              return   result;

       }

}



Here are a few tips on how to override these methods:

I. hashCode

1. Store some arbitary constant nonzero integer value, say 17, in an int variable called result.
2. For each significant field f in your object (each field taken into account by the equals( ) method), calculate an int hash code c for the field in the following manner:

Field type	Calculation
boolean	c = (f ? 0 : 1)
byte, char, short, or int	c = (int)f
long	c = (int)(f ^ (f >>>32))
float	c = Float.floatToIntBits(f);
double	long l = Double.doubleToLongBits(f); c = (int)(l ^ (l >>> 32))
Object, where equals( ) calls equals( ) for this field	c = f.hashCode( )
Array	Apply above rules to each element

1. Combine the hash code(s) computed above:
   result = 37 * result + c;
   where 37 can be replaced with any primary number
   
2. Return result.
3. Look at the resulting hashCode( ) and make sure that equal instances have equal hash codes.

II. equals

1. Use the equality == operator to check if the argument is the reference to this object, if yes. return true. This saves time when actual comparison is costly.
2. Check that the argument is not null and it is of the correct type, if not then return false.
   
   Note that, correct type does not mean the same type or class. It could be any class or interface that one or more classes agree to implement for providing the comparison.
3. Compare significant variables of both, the argument object and this object and check if they are equal. If *all* of them are equal then return true, otherwise return false. Again, as mentioned earlier, while comparing these class variables; primitive variables can be compared directly with an equality operator (==) after performing any necessary conversions (Such as float to Float.floatToIntBits or double to Double.doubleToLongBits). Whereas, object references can be compared by invoking their equals method recursively. You also need to ensure that invoking equals method on these object references does not result in a NullPointerException.
   
4. Do not change the type of the argument of the equals method. It takes a java.lang.Object as an argument, do not use your own class instead. If you do that, you will not be overriding the equals method, but you will be overloading it instead; which would cause problems.
   

Java : Adding multiple values to a key in a HashMap / Hashtable

Hi guys,

In today's example I will show you how to add multiple values to a key in a HashMap or Hashtable.

The key is to add the values in an ArrayList everytime.

Check out the next example for more :

/*

  *   @(#)HashMapMultipleValues.java       1.1   03/05/09

  *

  *   Copyright   2009   Lazy   Coder.   All   rights   reserved.

  *   To   be   used   only   for   educational   purposes.

  *   Not   to   be   reproduced   and   published

  *   without   seeking   prior   consent.

  */

package   com.lazy.coder.examples;



import   java.util.ArrayList;

import   java.util.HashMap;



/**

  *   @author   lazycoder

  *

  */

public   class   HashMapMultipleValues   {

      

       public   static   void   addMultipleValues(HashMap   map,  

                     Object   key,   Object   value){

              Object   prevValue   =   map.get(key);

              ArrayList   valueList;

              if(   prevValue   ==   null   ){

                       valueList   =   new   ArrayList();

                       map.put(key,   valueList);

              }else{

                     valueList   =   (ArrayList)prevValue;

              }

                valueList.add(value);

       }



       /**

         *   @param   args

         */

       public   static   void   main(String[]   args)   {

              HashMap   map   =   new   HashMap();

              String   key   =   "LazyCoder";

              addMultipleValues(map,   key,   "LazyCoder");

              addMultipleValues(map,   key,   "is");

              addMultipleValues(map,   key,   "Lazy");

             

              ArrayList   valuesList   =   (ArrayList)map.get(key);

              for(Object   value   :   valuesList){

                     System.out.println(value);

              }

       }



}


If done normally like this :
  map.put(key,   "LazyCoder");

  map.put(key,   "is");

  map.put(key,   "Lazy");

the old value gets overriden with the latest value put against the key in the HashMap
in this case "Lazy" will be saved against the key in map.

LazyCoder
Signing off for now...

Java : Converting java.util.Date to java.sql.Date

Many a times we need to insert the date of transaction in the database, but the problem is that the PreparedStatement Implementations have a setDate() method which takes java.sql.Date as an argument and same is the case with the ResultSet which is returned from the database as java.sql.Date is an equivalent to Date datatype in the DB.

But in java we can get current date from a new Object of java.util.Date, so here is how to convert it into java.sql.Date

java.util.Date today = new java.util.Date();

java.sql.Date date = new java.sql.Date(today .getTime());

java.sql.Date only saves the date though and not other attributes like day, time, timezone etc.

If the field in the Database is defined as DATETIME then we can use java.sql.Timestamp instead.

java.sql.Timestamp ts = new java.sql.Timestamp(today .getTime());

here is the result

System.out.println(today); ---> Fri May 01 17:54:26 IST 2009 (util.Date)
System.out.println(date); ---> 2009-05-01 (sql.Date)
System.out.println(ts); ---> 2009-05-01 17:54:26.199 (sql.Timestamp)

Timestamp doesn't hold timezone and day attributes.

Thats it for now folks.

LazyCoder
Signing off for now...

Bachachans showing middle finger after casting their vote

May Day being a holiday I lazily woke up at 9am, opened the door of my home to pick up the newspaper and there it was right on the front page, the Bachchans posing with their middle finger after casting their votes.

Bachchans


I was taken aback but still couldn't help giggling and was quite curious as to why the ink was applied to their middle finders instead of the index finger, right besides their photo, was a picture of Aamir Khan with his middle finger also inked.

I just got curious and performed a quick search only to find this article on TOI's website

Voters will now show middle finger

That sounds absurd and watching the celebrities posing in such a fashion is tasteless indeed.

Java Example : How To Swap Integer and String Variables Without Using a Temporary Variable

Hi guys,

Swapping two variable has always been a classic learning example for beginners, well for a change in the example below we would be learning to swap two variables (String or Integer) without using a temporary variable.

/*

  *   @(#)Swap.java       1.1   28/04/09

  *

  *   Copyright   2009   Lazy   Coder.   All   rights   reserved.

  *   To   be   used   only   for   educational   purposes.

  *   Not   to   be   reproduced   and   published

  *   without   seeking   prior   consent.

  */

package   com.lazy.coder.examples;





/**

  *   A   class   that   demonstrates   how   to   swap  

  *   two   strings   or   two   integers   without

  *   using   a   temporary   variable

  *  

  *   @author   lazycoder

  *  

  */

public   class   Swap   {



      

       /**

         *   @param   args

         */

       public   static   void   main(String[]   args)   {

              //Swapping   two   String   without   using   temp   variable.

              String   firstString   =   "Lazy";

              String   secondString   =   "LazyCoder";

              System.out.println("firstString   =   "   +   firstString);

              System.out.println("secondString   =   "   +   secondString);

              System.out.println("Swapping");

              firstString   =   firstString   +   secondString;

              secondString   =   firstString.substring(0,   firstString.length()

                            -   secondString.length());

              firstString   =   firstString.substring(secondString.length());

              System.out.println("firstString   =   "   +   firstString);

              System.out.println("secondString   =   "   +   secondString);

             

              //Swapping   two   Integers   without   using   temp   variable.

              int   firstInt   =   111111111;

              int   secondInt   =   999999999;

              System.out.println("firstInt   =   "   +   firstInt);

              System.out.println("secondInt   =   "   +   secondInt);

              System.out.println("Swapping");

              /*

                *   Using   exclusive-or   (XOR)   to   avoid  

                *   stack   overflow/underflow

                */

              firstInt   =   firstInt   ^   secondInt;

              secondInt   =   firstInt   ^   secondInt;

              firstInt   =   firstInt   ^   secondInt;

              System.out.println("firstInt   =   "   +   firstInt);

              System.out.println("secondInt   =   "   +   secondInt);

       }

}



Thats all for now, check back for more java examples.

Lazy Coder
signing off for now...