public List readSegments()

in src/main/java/org/apache/commons/imaging/formats/jpeg/JpegImageParser.java [934:1020]
68 lines of code
12 McCabe index (conditional complexity)

    public List<Segment> readSegments(final ByteSource byteSource, final int[] markers, final boolean returnAfterFirst) throws ImagingException, IOException {
        final List<Segment> result = new ArrayList<>();
        final int[] sofnSegments = {
                // kJFIFMarker,
                JpegConstants.SOF0_MARKER,
                JpegConstants.SOF1_MARKER,
                JpegConstants.SOF2_MARKER,
                JpegConstants.SOF3_MARKER,
                JpegConstants.SOF5_MARKER,
                JpegConstants.SOF6_MARKER,
                JpegConstants.SOF7_MARKER,
                JpegConstants.SOF9_MARKER,
                JpegConstants.SOF10_MARKER,
                JpegConstants.SOF11_MARKER,
                JpegConstants.SOF13_MARKER,
                JpegConstants.SOF14_MARKER,
                JpegConstants.SOF15_MARKER,
        };

        final JpegUtils.Visitor visitor = new JpegUtils.Visitor() {
            // return false to exit before reading image data.
            @Override
            public boolean beginSos() {
                return false;
            }

            // return false to exit traversal.
            @Override
            public boolean visitSegment(final int marker, final byte[] markerBytes,
                    final int markerLength, final byte[] markerLengthBytes,
                    final byte[] segmentData) throws ImagingException, IOException {
                if (marker == JpegConstants.EOI_MARKER) {
                    return false;
                }

                // Debug.debug("visitSegment marker", marker);
                // // Debug.debug("visitSegment keepMarker(marker, markers)",
                // keepMarker(marker, markers));
                // Debug.debug("visitSegment keepMarker(marker, markers)",
                // keepMarker(marker, markers));

                if (!keepMarker(marker, markers)) {
                    return true;
                }

                switch (marker) {
                case JpegConstants.JPEG_APP13_MARKER:
                    // Debug.debug("app 13 segment data", segmentData.length);
                    result.add(new App13Segment(marker, segmentData));
                    break;
                case JpegConstants.JPEG_APP14_MARKER:
                    result.add(new App14Segment(marker, segmentData));
                    break;
                case JpegConstants.JPEG_APP2_MARKER:
                    result.add(new App2Segment(marker, segmentData));
                    break;
                case JpegConstants.JFIF_MARKER:
                    result.add(new JfifSegment(marker, segmentData));
                    break;
                default:
                    if (Arrays.binarySearch(sofnSegments, marker) >= 0) {
                        result.add(new SofnSegment(marker, segmentData));
                    } else if (marker == JpegConstants.DQT_MARKER) {
                        result.add(new DqtSegment(marker, segmentData));
                    } else if ((marker >= JpegConstants.JPEG_APP1_MARKER)
                            && (marker <= JpegConstants.JPEG_APP15_MARKER)) {
                        result.add(new UnknownSegment(marker, segmentData));
                    } else if (marker == JpegConstants.COM_MARKER) {
                        result.add(new ComSegment(marker, segmentData));
                    }
                    break;
                }

                return !returnAfterFirst;
            }

            @Override
            public void visitSos(final int marker, final byte[] markerBytes,
                    final byte[] imageData) {
                // don't need image data
            }
        };

        new JpegUtils().traverseJfif(byteSource, visitor);

        return result;
    }