jpegmetadata.java

java1.6众多例子参考

    protected IIOMetadataNode getStandardTextNode() {
        IIOMetadataNode text = null;
        // Add a text entry for each COM Marker Segment
        if (findMarkerSegment(JPEG.COM) != null) {
            text = new IIOMetadataNode("Text");
            Iterator iter = markerSequence.iterator();
            while (iter.hasNext()) {
                MarkerSegment seg = (MarkerSegment) iter.next();
                if (seg.tag == JPEG.COM) {
                    COMMarkerSegment com = (COMMarkerSegment) seg;
                    IIOMetadataNode entry = new IIOMetadataNode("TextEntry");
                    entry.setAttribute("keyword", "comment");
                    entry.setAttribute("value", com.getComment());
                text.appendChild(entry);
                }
            }
        }
        return text;
    }

    protected IIOMetadataNode getStandardTransparencyNode() {
        IIOMetadataNode trans = null;
        if (hasAlpha == true) {
            trans = new IIOMetadataNode("Transparency");
            IIOMetadataNode alpha = new IIOMetadataNode("Alpha");
            alpha.setAttribute("value", "nonpremultiplied"); // Always assume
            trans.appendChild(alpha);
        }
        return trans;
    }

    // Editing

    public boolean isReadOnly() {
        return false;
    }

    public void mergeTree(String formatName, Node root)
        throws IIOInvalidTreeException {
        if (formatName == null) {
            throw new IllegalArgumentException("null formatName!");
        } 
        if (root == null) {
            throw new IllegalArgumentException("null root!");
        }
        List copy = null;
        if (resetSequence == null) {
            resetSequence = cloneSequence();  // Deep copy
            copy = resetSequence;  // Avoid cloning twice
        } else {
            copy = cloneSequence();
        }
        if (isStream &&
            (formatName.equals(JPEG.nativeStreamMetadataFormatName))) {
                mergeNativeTree(root);
        } else if (!isStream &&
                   (formatName.equals(JPEG.nativeImageMetadataFormatName))) {
            mergeNativeTree(root);
        } else if (!isStream &&
                   (formatName.equals
                    (IIOMetadataFormatImpl.standardMetadataFormatName))) {
            mergeStandardTree(root);
        } else {
            throw  new IllegalArgumentException("Unsupported format name: " 
                                                + formatName);
        }
        if (!isConsistent()) {
            markerSequence = copy;
            throw new IIOInvalidTreeException
                ("Merged tree is invalid; original restored", root);
        }
    }

    private void mergeNativeTree(Node root) throws IIOInvalidTreeException {
        String name = root.getNodeName();
        if (name != ((isStream) ? JPEG.nativeStreamMetadataFormatName
                                : JPEG.nativeImageMetadataFormatName)) {
            throw new IIOInvalidTreeException("Invalid root node name: " + name, 
                                              root);
        }
        if (root.getChildNodes().getLength() != 2) { // JPEGvariety and markerSequence
            throw new IIOInvalidTreeException(
                "JPEGvariety and markerSequence nodes must be present", root);
        }
        mergeJFIFsubtree(root.getFirstChild());
        mergeSequenceSubtree(root.getLastChild());
    }

    /**
     * Merge a JFIF subtree into the marker sequence, if the subtree
     * is non-empty.
     * If a JFIF marker exists, update it from the subtree.
     * If none exists, create one from the subtree and insert it at the
     * beginning of the marker sequence.
     */
    private void mergeJFIFsubtree(Node JPEGvariety) 
        throws IIOInvalidTreeException {
        if (JPEGvariety.getChildNodes().getLength() != 0) {
            Node jfifNode = JPEGvariety.getFirstChild();
            // is there already a jfif marker segment?
            JFIFMarkerSegment jfifSeg = 
                (JFIFMarkerSegment) findMarkerSegment(JFIFMarkerSegment.class, true);
            if (jfifSeg != null) {
                jfifSeg.updateFromNativeNode(jfifNode, false);
            } else {
                // Add it as the first element in the list.
                markerSequence.add(0, new JFIFMarkerSegment(jfifNode));
            }
        }
    }

    private void mergeSequenceSubtree(Node sequenceTree) 
        throws IIOInvalidTreeException {
        NodeList children = sequenceTree.getChildNodes();
        for (int i = 0; i < children.getLength(); i++) {
            Node node = children.item(i);
            String name = node.getNodeName();
            if (name.equals("dqt")) {
                mergeDQTNode(node);
            } else if (name.equals("dht")) {
                mergeDHTNode(node);
            } else if (name.equals("dri")) {
                mergeDRINode(node);
            } else if (name.equals("com")) {
                mergeCOMNode(node);
            } else if (name.equals("app14Adobe")) {
                mergeAdobeNode(node);
            } else if (name.equals("unknown")) {
                mergeUnknownNode(node);
            } else if (name.equals("sof")) {
                mergeSOFNode(node);
            } else if (name.equals("sos")) {
                mergeSOSNode(node);
            } else {
                throw new IIOInvalidTreeException("Invalid node: " + name, node);
            }
        }
    }

    /**
     * Merge the given DQT node into the marker sequence.  If there already
     * exist DQT marker segments in the sequence, then each table in the 
     * node replaces the first table, in any DQT segment, with the same
     * table id.  If none of the existing DQT segments contain a table with
     * the same id, then the table is added to the last existing DQT segment.
     * If there are no DQT segments, then a new one is created and added
     * as follows:
     * If there are DHT segments, the new DQT segment is inserted before the
     * first one.  
     * If there are no DHT segments, the new DQT segment is inserted before
     * an SOF segment, if there is one. 
     * If there is no SOF segment, the new DQT segment is inserted before 
     * the first SOS segment, if there is one.
     * If there is no SOS segment, the new DQT segment is added to the end
     * of the sequence.
     */
    private void mergeDQTNode(Node node) throws IIOInvalidTreeException {
        // First collect any existing DQT nodes into a local list
        ArrayList oldDQTs = new ArrayList();
        Iterator iter = markerSequence.iterator();
        while (iter.hasNext()) {
            MarkerSegment seg = (MarkerSegment) iter.next();
            if (seg instanceof DQTMarkerSegment) {
                oldDQTs.add(seg);
            }
        }
        if (!oldDQTs.isEmpty()) {
            NodeList children = node.getChildNodes();
            for (int i = 0; i < children.getLength(); i++) {
                Node child = children.item(i);
                int childID = MarkerSegment.getAttributeValue(child, 
                                                              null, 
                                                              "qtableId", 
                                                              0, 3, 
                                                              true);
                DQTMarkerSegment dqt = null;
                int tableIndex = -1;
                for (int j = 0; j < oldDQTs.size(); j++) {
                    DQTMarkerSegment testDQT = (DQTMarkerSegment) oldDQTs.get(j);
                    for (int k = 0; k < testDQT.tables.size(); k++) {
                        DQTMarkerSegment.Qtable testTable = 
                            (DQTMarkerSegment.Qtable) testDQT.tables.get(k);
                        if (childID == testTable.tableID) {
                            dqt = testDQT;
                            tableIndex = k;
                            break;
                        }
                    }
                    if (dqt != null) break;
                }
                if (dqt != null) {
                    dqt.tables.set(tableIndex, dqt.getQtableFromNode(child));
                } else {
                    dqt = (DQTMarkerSegment) oldDQTs.get(oldDQTs.size()-1);
                    dqt.tables.add(dqt.getQtableFromNode(child));
                }
            }
        } else {
            DQTMarkerSegment newGuy = new DQTMarkerSegment(node);
            int firstDHT = findMarkerSegmentPosition(DHTMarkerSegment.class, true);
            int firstSOF = findMarkerSegmentPosition(SOFMarkerSegment.class, true);
            int firstSOS = findMarkerSegmentPosition(SOSMarkerSegment.class, true);
            if (firstDHT != -1) {
                markerSequence.add(firstDHT, newGuy);
            } else if (firstSOF != -1) {
                markerSequence.add(firstSOF, newGuy);
            } else if (firstSOS != -1) {
                markerSequence.add(firstSOS, newGuy);
            } else {
                markerSequence.add(newGuy);
            }
        }
    }

    /**
     * Merge the given DHT node into the marker sequence.  If there already
     * exist DHT marker segments in the sequence, then each table in the 
     * node replaces the first table, in any DHT segment, with the same
     * table class and table id.  If none of the existing DHT segments contain
     * a table with the same class and id, then the table is added to the last
     * existing DHT segment.
     * If there are no DHT segments, then a new one is created and added
     * as follows:
     * If there are DQT segments, the new DHT segment is inserted immediately
     * following the last DQT segment.
     * If there are no DQT segments, the new DHT segment is inserted before
     * an SOF segment, if there is one. 
     * If there is no SOF segment, the new DHT segment is inserted before 
     * the first SOS segment, if there is one.
     * If there is no SOS segment, the new DHT segment is added to the end
     * of the sequence.
     */
    private void mergeDHTNode(Node node) throws IIOInvalidTreeException {
        // First collect any existing DQT nodes into a local list
        ArrayList oldDHTs = new ArrayList();
        Iterator iter = markerSequence.iterator();
        while (iter.hasNext()) {
            MarkerSegment seg = (MarkerSegment) iter.next();
            if (seg instanceof DHTMarkerSegment) {
                oldDHTs.add(seg);
            }
        }
        if (!oldDHTs.isEmpty()) {
            NodeList children = node.getChildNodes();
            for (int i = 0; i < children.getLength(); i++) {
                Node child = children.item(i);
                NamedNodeMap attrs = child.getAttributes();
                int childID = MarkerSegment.getAttributeValue(child, 
                                                              attrs, 
                                                              "htableId", 
                                                              0, 3, 
                                                              true);
                int childClass = MarkerSegment.getAttributeValue(child, 
                                                                 attrs, 
                                                                 "class", 
                                                                 0, 1, 
                                                                 true);
                DHTMarkerSegment dht = null;
                int tableIndex = -1;
                for (int j = 0; j < oldDHTs.size(); j++) {
                    DHTMarkerSegment testDHT = (DHTMarkerSegment) oldDHTs.get(j);
                    for (int k = 0; k < testDHT.tables.size(); k++) {
                        DHTMarkerSegment.Htable testTable = 
                            (DHTMarkerSegment.Htable) testDHT.tables.get(k);
                        if ((childID == testTable.tableID) && 
                            (childClass == testTable.tableClass)) {
                            dht = testDHT;
                            tableIndex = k;
                            break;
                        }
                    }
                    if (dht != null) break;
                }
                if (dht != null) {
                    dht.tables.set(tableIndex, dht.getHtableFromNode(child));
                } else {
                    dht = (DHTMarkerSegment) oldDHTs.get(oldDHTs.size()-1);
                    dht.tables.add(dht.getHtableFromNode(child));
                }
            }
        } else {
            DHTMarkerSegment newGuy = new DHTMarkerSegment(node);
            int lastDQT = findMarkerSegmentPosition(DQTMarkerSegment.class, false);
            int firstSOF = findMarkerSegmentPosition(SOFMarkerSegment.class, true);
            int firstSOS = findMarkerSegmentPosition(SOSMarkerSegment.class, true);
            if (lastDQT != -1) {
                markerSequence.add(lastDQT+1, newGuy);
            } else if (firstSOF != -1) {
                markerSequence.add(firstSOF, newGuy);
            } else if (firstSOS != -1) {
                markerSequence.add(firstSOS, newGuy);
            } else {
                markerSequence.add(newGuy);
            }
        }
    }

    /**
     * Merge the given DRI node into the marker sequence.
     * If there already exists a DRI marker segment, the restart interval 
     * value is updated.
     * If there is no DRI segment, then a new one is created and added as
     * follows:
     * If there is an SOF segment, the new DRI segment is inserted before
     * it.
     * If there is no SOF segment, the new DRI segment is inserted before 
     * the first SOS segment, if there is one.
     * If there is no SOS segment, the new DRI segment is added to the end
     * of the sequence.
     */
    private void mergeDRINode(Node node) throws IIOInvalidTreeException {
        DRIMarkerSegment dri =
            (DRIMarkerSegment) findMarkerSegment(DRIMarkerSegment.class, true);
        if (dri != null) {
            dri.updateFromNativeNode(node, false);
        } else {
            DRIMarkerSegment newGuy = new DRIMarkerSegment(node);
            int firstSOF = findMarkerSegmentPosition(SOFMarkerSegment.class, true);
            int firstSOS = findMarkerSegmentPosition(SOSMarkerSegment.class, true);
            if (firstSOF != -1) {
                markerSequence.add(firstSOF, newGuy);
            } else if (firstSOS != -1) {
                markerSequence.add(firstSOS, newGuy);
            } else {
                markerSequence.add(newGuy);
            }
        }
    }

    /**
     * Merge the given COM node into the marker sequence.
     * A new COM marker segment is created and added to the sequence 
     * using insertCOMMarkerSegment.
     */