Question

Every time i come across the value “-15” i want to put it in a new byte array… how would i do this? I think i’m just tired and getting way to confused and worked up… please help… code is as follows:

    fileContent = "S107184CB78120EA52S107184CB78120EA57"; 
    int len = fileContent.length(); 
    byte[] data = new byte[len/2]; 
    for (int i = 0; i < len; i += 2) 
    {
        data[i / 2] = (byte) ((Character.digit(fileContent.charAt(i), 16) << 4) + Character.digit(fileContent.charAt(i+1), 16));
    }

this will give me the following: [-15, 7, 24, 76, -73, -127, 32, -22, 82, -15, 7, 24, 76, -73, -127, 32, -22, 87]

what i want from here is to have every element from -15 up until the next -15 (but not including it) in a separate byte array. i want to do that every time i come across another -15.. how would i do this?

Answer 1

Assuming -15‘s occur randomly, you need a dynamic array, which in java is a List.
Once you’ve collected up all your elements, you can convert the List to an array easily enough.

It would look something like this:

String fileContent = "S107184CB78120EA52S107184CB78120EA57";
int len = fileContent.length();
List<Byte[]> arrays = new ArrayList<Byte[]>();
List<Byte> data = new ArrayList<Byte>();
for (int i = 0; i < len; i += 2) {
    byte b = (byte) ((Character.digit(fileContent.charAt(i), 16) << 4) + Character.digit(fileContent.charAt(i + 1), 16));
    if (b == -15) {
        arrays.add(data.toArray(new Byte[data.size()]));
        data.clear();
    }
    data.add(b);
}
arrays.add(data.toArray(new Byte[data.size()]));

Note that this creates a List<Byte[]>, not a List<byte[]>. I chose this because I could use the .toArray() method of List. If you want a List<byte[]>, you’ll need to manually literate over data in the if block.