Re: how to solve this problem : out of memory

From:

Patricia Shanahan <pats@acm.org>

Newsgroups:

comp.lang.java.programmer

Date:

Tue, 03 Oct 2006 04:00:40 GMT

Message-ID:

<IflUg.9370$UG4.3067@newsread2.news.pas.earthlink.net>

Arne Vajh?j wrote:

Patricia Shanahan wrote:

Arne Vajh?j wrote:

Vishu wrote:

.. setting the arraylist's reference to null when you are done using
it..will alteast help the GC do its magic..;

In general it is considered bad practice to explicit
set to null.

Why?

It clutters code and does not improve performance
(in 99% of cases).

I am not the right person to explain GC.

But read:

Effective Java / Bloch - item 5.

or read the long thread at:

http://www.theserverside.com/news/thread.tss?thread_id=36362

It is worth noting that there are special cases where it do
improve performance, but those are the exceptions.

It is indeed bad practice to add ANY statement to a program unless it is
going to do some good.

I don't see why assigning null to a reference variable should be singled
out as being bad practice, rather that just falling under the general
rule of avoiding useless code. I have found it to be an effective
technique for reducing memory footprint under the following conditions:

1. The reference variable or array element itself has a long lifetime.
Don't do it for a local variable just before the method containing it
returns.

2. It may be the last reference to the data structure. The payoff is for
making some object or objects unreachable, so that GC can take them away.

3. The data structure is large enough to care about.

Patricia