Re: Query regd. memory usage

From:
"Matt Humphrey" <matth@ivizNOSPAM.com>
Newsgroups:
comp.lang.java.programmer
Date:
Wed, 9 May 2007 08:06:50 -0400
Message-ID:
<3omdnTo_k5V6JdzbnZ2dnUVZ_qGjnZ2d@adelphia.com>
"Sunil" <chinnam.sunil@gmail.com> wrote in message
news:1178686580.920279.302660@o5g2000hsb.googlegroups.com...
| Hi ,
|
| I have a method which takes a list of beans as parameter and does some
| insertions into the database. I have something like this inside the
| for loop:
|
| for(int i=0;i<list.size();i++){
| MyBean bean = new MyBean();
| ....................
| ....................
| }
|
|
| Initializing the bean inside the for loop is mandatory.
| Will initializing the bean inside the for loop cause more memory
| usage?
| Or is this better?
|
| MyBean bean = null;
| for(int i=0;i<list.size();i++){
| bean = new MyBean();
| ....................
| ....................
| }
| Which of the above two constructs is better?
| My guess is both of them consume the same amount of memory. And there
| is no difference in the performance either.

Your guess is right--there is virtually no difference to the two
constructions because both allocate the same number of bean objects--the
location of the declaration does not affect the time or memory.
Furthermore, if you are inserting into the database on each pass through the
loop, the network and disk traffic will far exceed anything you do in the
program.

If you determine through profiling that the list and MyBean are so large
that they're a problem, you could get allocate only one and reuse it.

MyBean bean = new MyBean ();
for (int i = 0; i < list.size(); i++) {
    // set the full bean contents, apply and insert
}

Matt Humphrey matth@ivizNOSPAM.com http://www.iviz.com/

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