If I undertstand your suggestion correctly, then the technique you
suggest doesn't work, at least not with the Eclipse compiler. If you
declare the variable being returned before the try/catch statements,
but set the value within the try statement, the Eclipse compiler
complains that you could be returning a value that may not be
initialized. This means you end up setting the variable you want to
return to null before the try statement, instead of setting it to null
after. Either way, the null value will not be returned, and it doesn't
matter whether it is set before or after. In essence, the same problem
exists.
Perhaps using your technique makes more sense for someone reading the
code, in which case I should adopt it. Still, it would be nice if the
Java compiler could recognize that only one of two execution paths are
possible with this method. In the first the try statement properly
intializes the return value and returns it to the caller, or the catch
statement throws the exception. In no execution scenario does a null
value need to be returned.
Its almost like the compiler is failing to recognize the exception,
and still expects the method to return a value when the exception will
be thrown because of error conditions.
Maybe I'm missing an obvious part of the picture.
The Sunburned Surveyor
On Jan 29, 2008 12:28 PM, Stefan Steiniger <[EMAIL PROTECTED]> wrote:
> mhm.. I don't realy get why you put the first return into the try case?
> why should one return within a function and not at the end of a method?
> (i.e. i have never seen this in java code)
>
> instead declear a new method variable and set their value within try{}
> and/or catch{} and return this variable at the end.
>
> stefan
>
> Sunburned Surveyor schrieb:
>
> > I've got a quick question about the best way to handle return values
> > in Java methods with a try/catch statement. Consider, as an example,
> > the following method:
> >
> > public static SurveyorsAngle getSupplementaryAngle(SurveyorsAngle argAngle)
> > {
> > try
> > {
> > SurveyorsAngle halfRevolution = new BasicSurveyorsAngle(0.50);
> > SurveyorsAngle toReturn =
> > AngleCruncher.subtractAngles(halfRevolution, argAngle);
> > return toReturn;
> > }
> >
> > catch(ShouldNeverReachHere caught)
> > {
> > System.err.println(caught.getMessage());
> > }
> >
> > return null;
> > }
> >
> > In this example the return value must be set within the try statement,
> > becuase the subtractAngles method throws an exception.
> >
> > This means that the method has to return a null value after the
> > try/catch statements. However, this return statement will never be
> > reached, because the method will either [1] return from the try
> > statement with a valid SurveyorsAngle object or [2] execution will
> > shift to the catch statement.
> >
> > However, if I remove the return null statement from the end of this
> > method, Eclipse gives me a compile error. This error states that the
> > getSupplementaryAngle method must return a SurveyorsAngle value.
> >
> > I seem to run into this a lot in my code. I know I could just
> > eiliminate the try/catch statement and add a throws clause to the
> > containing method, but sometimes the exception SHOULD be handled in
> > the containing method.
> >
> > Is there a better solution? It seems like the compiler is requiring a
> > return statement that can never be reached.
> >
> > Thanks for any advice on this.
> >
> > The Sunburned Surveyor
> >
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