Primitive Byte Array Chunking and Hashing in Spring Endpoints

@RestController
@RequestMapping("/api/chunks")
public class ChunkProcessingController {
 
    @PostMapping("/checksum")
    public ResponseEntity<String> computeChecksum(@RequestBody byte[] rawPayload) {
        int chunkSize = 1024;
        int totalLength = rawPayload.length;
        MessageDigest digest = getSha256Digest();
 
        for (int offset = 0; offset < totalLength; offset += chunkSize) {
            int currentChunkLength = Math.min(chunkSize, totalLength - offset);
            digest.update(rawPayload, offset, currentChunkLength);
        }
 
        return ResponseEntity.ok(HexFormat.of().formatHex(digest.digest()));
    }
 
    private MessageDigest getSha256Digest() {
        try {
            return MessageDigest.getInstance("SHA-256");
        } catch (NoSuchAlgorithmException e) {
            throw new IllegalStateException("SHA-256 unavailable", e);
        }
    }
}