Databases
StackOverflow2013
Postsdbo
POWhat are some Java memory management best practices?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POWhat are some Java memory management best practices?
    primarykey
    data
    text
    <p>I am taking over some applications from a previous developer. When I run the applications through Eclipse, I see the memory usage and the heap size increase a lot. Upon further investigation, I see that they were creating an object over-and-over in a loop as well as other things.</p> <p>I started to go through and do some clean up. But the more I went through, the more questions I had like "will this actually do anything?"</p> <p>For example, instead of declaring a variable outside the loop mentioned above and just setting its value in the loop... they created the object in the loop. What I mean is:</p> <pre><code>for(int i=0; i &lt; arrayOfStuff.size(); i++) { String something = (String) arrayOfStuff.get(i); ... } </code></pre> <p>versus</p> <pre><code>String something = null; for(int i=0; i &lt; arrayOfStuff.size(); i++) { something = (String) arrayOfStuff.get(i); } </code></pre> <p>Am I incorrect to say that the bottom loop is better? Perhaps I am wrong. </p> <p>Also, what about after the second loop above, I set "something" back to null? Would that clear out some memory?</p> <p>In either case, what are some good memory management best practices I could follow that will help keep my memory usage low in my applications?</p> <p><strong>Update:</strong></p> <p>I appreciate everyones feedback so far. However, I was not really asking about the above loops (although by your advice I did go back to the first loop). I am trying to get some best practices that I can keep an eye out for. Something on the lines of "when you are done using a Collection, clear it out". I just really need to make sure not as much memory is being taken up by these applications.</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. UScherouvim
    1. USAscalonian
    plurals
    1. PL
      singulars
      1. LTLinked
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    3. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POWhat are some Java memory management best practices?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POWhat are some Java memory management best practices?
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POWhat are some Java memory management best practices?
      1. This table or related slice is empty.
      1. VTUpMod
    1. CORe your edit: As three people have said so far, profile it!
      singulars
      1. POWhat are some Java memory management best practices?
      1. USMichael Myers
    2. COI am looking for some specific practices to use so I don't have to have someone profile it. I would rather develop it properly in the first place than to code, hope it works, profile it, and make fixes.
      singulars
      1. POWhat are some Java memory management best practices?
      1. USAscalonian
    3. COThe "specific practice" is to write well structured code without doing premature optimization, and then profiling it to find out what needs optimizing.
      singulars
      1. POWhat are some Java memory management best practices?
      1. USEsko Luontola
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload