Re: SSCCE of my graphical interface with memory leak

From:
Lew <lew@lewscanon.com>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 22 Oct 2007 11:14:18 -0400
Message-ID:
<EtadnYZhm93XI4HanZ2dnUVZ_umlnZ2d@comcast.com>
Sal wrote:

System.gc();
System.runFinalization();
System.gc();


Don't use these calls.

Don't use TABs in Usenet posts.

double impVmin =0;

....

JLabel labelVmin = null;


No need to initialize instance variables to zero or null; that's what happens
already.

String data_med_h = "";


It is often better to leave String instance variables at null rather than
initialize them to a throwaway value.

double Vmin = 30;
double Vmax= 10030;
double Smax =10030;


If these magic numbers are significant, you should make them static final
variables, i.e., compile-time constants (and therefore use all upper-case
variable names for them).

You also should use double literals to initialize double variables.

catch(Exception e) {}


Do not ignore exceptions. Log'em and handle'em.

UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());


Why did you do this more than once?

You have done everything in the constructor. Move all the real work out of
the constructor. It is dangerous to perform a whole lot of action inside an
incompletely-constructed object.

Refactor your two windows to be instantiated by separate classes, or at least
by separate methods.

Likewise with the different branches of "if ( ae.getSource()...)" blocks -
they belong in separate methods.

Make sure GUI actions happen on the EDT and that non-GUI actions don't.

See if you can make your SSCCE actually a *short* self-contained compilable
example.

<http://www.physci.org/codes/sscce.html>

--
Lew

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