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Import statement in Java Program

Posted on 2002-06-05
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Last Modified: 2010-03-31
I am using java.util.Vector in my Java program. So, I need to import that class into my program.
This can be done either by ...
import java.util.*;
or
import java.util.Vector;
Which one will be the right one? Will there be any performance issue when importing the whole package instead of just the class file which I am using?
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Question by:JavaRam
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girionis earned 50 total points
ID: 7056136
 It does not actually matter and there are no performance issues if you import the whole package instead of a single class. The classes are imported and used at compile time in a Java application. When you do an import java.util.*; you are not actually loading all the classes in memory, you just indicate to the VM where to find the classes during compilation time.

  But it is a good programming practice to import classes separately since it gives a clearer view of what class resides within which package.

  Hope it helps.
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Expert Comment

by:BaneBane
ID: 7056180
As far as I know there is no deference btween the two. the compiler will only link the classes that you need not the *.

Hope this helps.
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Expert Comment

by:pran071199
ID: 7058868
As a good practice /coding convention

use import java.util.Vector;  if you are using only Vector class from java.util package.

if you are using more than one Class from package use
java.util.*;
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