ArrayIndexOutOfBoundsException while reading data from file android

Question

I am uploading video using multipartentity in chunks, to upload I am reading data from file. In the first loop I am able to read data, but in the next loop it is getting ArrayIndexOutOfBoundsException

Exception :

> java.lang.ArrayIndexOutOfBoundsException: length=1024;
> regionStart=1024; regionLength=1024

I am reading 1024 bytes in every loop.

totalSize = 441396

offset starts from 0

chunkSize = 1024

My code:

do {
    currentChunkSize = totalSize - offset > chunkSize ? chunkSize : totalSize - offset;

    String urlString = "http://capmem.omsoftware.co/Event/UploadVideo?" +
                            "callback=localJsonpCallback&" +
                            "filename="+ filename +"&" +
                            "ext="+ exten +"&" +
                            "totalsize="+ size +"&" +
                            "EventID="+ eventid +"&" +
                            "UserID="+ userid +"&" +
                            "comment="+ coment +"&" +
                            "VideoLength="+ videolength +
                            "&chunk=" + currentChunkSize;

    httppost1 = new HttpPost(urlString);

    byte[] currentBytes = new byte[currentChunkSize];
    buf = new BufferedInputStream(new FileInputStream(file));
    buf.read(currentBytes, offset, currentChunkSize);

    offset += currentChunkSize;

    MultipartEntity reqEntity = new MultipartEntity();
    reqEntity.addPart("videofile", new ByteArrayBody(currentBytes, "application/octet-stream", filename));

    httppost1.setEntity(reqEntity);
    DefaultHttpClient httpClient = new DefaultHttpClient();
    HttpResponse response = httpClient.execute(httppost1);
    int resCode = response.getStatusLine().getStatusCode();

} while(totalSize != offset);

Getting Exception in

buf.read(currentBytes, offset, currentChunkSize);

Answer 1

The offset parameter is the offset into currentBytes you want to write, not the offset into the stream. Since currentBytes is of length currentChunkSize, if offset is anything other than 0 you'll go past the end of the array.

Answer 2

your currentChunkSize is always 1024 since your only check is

currentChunkSize = totalSize - offset > chunkSize ? chunkSize : totalSize - offset;

you never modify the totalSize . You need to know how many bytes are left to determine the chunk size you need.

Try adding

totalSize = totalSize-currentChunkSize; 

also you can change the while condition to

while(totalSize!=0)

and even better to change it to a pre-condition loop instead of the do-while (the file might be empty)