Java DataBuffer类的原因是什么？

Question

When I was about to investigate the internal implementation of the BufferedImage class in Java, I came across the DataBuffer . The DataBuffer is in finally used to save the blank image data, which can only be interpreted with the related ColorModel and SampleModel implementation. However, I do not understand the real purpose of the DataBuffer beside of the fact, that it wraps arrays of the same type with some read and write helpers.

Answer 1

DataBuffer is an abstraction, so that BufferedImage does not need to know about actual pixel storage.

Pixels are usually stored in arrays, but it can be a single packed or interleaved array, or it can be a single or multiple banded arrays. Multiply that with the number of transfer types supported, and you will see there's a lot of different cases to handle. It makes a lot of sense to delegate this to specialized implementations, and avoid having knowledge about all these different types in BufferedImage itself.

But it doesn't even have to be an array at all. As an example, I have successfully implemented DataBuffer s backed by nio ByteBuffer s and memory mapped files.