Useless code in java.awt.image.SampleModel.java?

Question

Hey there,
i just looked up the sourcecode of java.awt.image.SampleModel.java in JDK 6
I discovered two issues i'd like to discuss.
1) on lines 736 to 739 this code is stated:
if (iArray != null)
pixels = iArray;
else
pixels = new int[numBands * w * h];
I asked myself, why does this code exist? while the getPixels() method is overwritten twice by double[] getPixels() and float[] getPixels, it is impossible to reach the part of the java code that initializes the pixels-array. One could only step into that line if "null" is given for the i/d/fArray-parameter. but if one would do so, the Java parser couldn't determine, which method is to use. so this part of code is just useless IMHO.
the java developers could get a little more performance out of this method if the if statement would be cut out - especially when reading a lot of very small rasters
or, on the other hand, they could replace this piece of code by an explicit bounds check.
When somebody touches this code, i would appreciate it if the errormessage "index out of bounds!" could be rewritten to be a little more verbose, like: Index out of bounds(x=123; y=456, maxX=100, maxY=400)!(numbers are just examples)
I hope i didn't miss something very basic and could help improving this class a little bit.
2) the local variable Offset(line 734) is coded against code conventions which say, variables shall start with a lowercase letter. Offset obviously doesn't fit that convention.
best regards
kdot

Answer 1

One could only step into that line if "null" is given for the i/d/fArray-parameter. but if one would do so, the Java parser couldn't determine, which method is to use. so this part of code is just useless IMHO. You can have
sampleModel.getPixels(x,y,w,h,(int[]) null, dataBuffer);No ambiguity on which method to use.
the local variable Offset(line 734) is coded against code conventions which say, variables shall start with a lowercase letter. Offset obviously doesn't fit that convention. You're correct, offset is against coding conventions. So are many other examples scattered throughout the jdk source code. For example, Hashtable should be called HashTable. In some cases the coding conventions might not have been established when the original code was written. In other cases it might have been human error. In yet other cases the conventions were probably ignored. The person who wrote the SampleModel class did so some 10+ years ago (Java 1.2). Who knows what he/she was thinking at the time, and in all honesty - does it really matter in this case?
Did you know there are some classes that declare unused local variables (ahem ColorConvertOp)? Some also have unused imports ( *** cough *** BufferedImage *** cough *** ). In essence, the jdk source code is not the epidemy of code correctness. But it's still pretty good.