In the following example, I get both warnings, the former on the first occurrence of 'data' and the latter on 'dataBuffer.getData()':

"The array is only written to, never read from" and "The assigned value is never used"

When I comment out the for loop (so 'data' is actually not used), the second warning disappears, and the first stays. This is wrong, because 'data' is not written to anymore.

When I change '10000' to 'data.length', both warnings disappear.

public class Temp {
    public static void main(String[] args) {
        BufferedImage img = new BufferedImage(100, 100, BufferedImage.TYPE_INT_RGB);
        img.setAccelerationPriority(0);

        WritableRaster raster = img.getRaster();
        DataBufferInt dataBuffer = (DataBufferInt)raster.getDataBuffer();
        int[] data = dataBuffer.getData();

        for (int p = 0; p < 10000; p++) data[p++] = p/*something*/;
    }
}

The program works fine nontheless (the image updates as expected).