Why am I getting an ArraIndexOutOfBoundException?

Question

I am trying to copy an byte array (fileData), which I read from a file, into another byte array (subdata) (below the code):

                ByteBuffer inputBuffer = decoderInputBuffers[intBufIndex];
                int limit = inputBuffer.capacity();
                int pos = frameIndex * limit;
                byte[] subData = new byte[limit];

                System.arraycopy(fileData, pos, subData, 0, subData.length);

My question is why I am gettng this error?

java.lang.ArrayIndexOutOfBoundsException: src.length=732542 srcPos=0 dst.length=1572864 dstPos=0 length=1572864

How ist that even possible since I say explicitly say what the size of the array should be.

Really? I thought I am trying to copy subdata.length_ of _filedata_ into into _subdata_ Or am I wrong? Here is a link: (https://www.tutorialspoint.com/java/lang/system_arraycopy.htm) — KOalaDelYtaPLaYa, Feb 18 '20 at 15:59
I think the problem is that I try to put 732.542 into 1.572.864. Ad instead of sudata.length I should give fileData.lenth so I will not try to grab arrays which dont exist. — KOalaDelYtaPLaYa, Feb 18 '20 at 16:33

score 1 · Accepted Answer · answered Feb 18 '20 at 16:33

If you look at the docs (which you have linknd in comments) it says that the last parameter of the function is:

length − This is the number of array elements to be copied.

so if you look closely you are trying to copy 1572864 from an array of 732542 and that's why you are getting the exception

Why am I getting an ArraIndexOutOfBoundException?

1 Answers1