1 /*
2 * Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.imageio.plugins.jpeg;
27
28 import javax.imageio.metadata.IIOInvalidTreeException;
29 import javax.imageio.metadata.IIOMetadataNode;
30 import javax.imageio.stream.ImageOutputStream;
31
32 import java.io.IOException;
33
34 import org.w3c.dom.Node;
35 import org.w3c.dom.NamedNodeMap;
36
37 /**
38 * All metadata is stored in MarkerSegments. Marker segments
39 * that we know about are stored in subclasses of this
40 * basic class, which used for unrecognized APPn marker
41 * segments. XXX break out UnknownMarkerSegment as a subclass
42 * and make this abstract, avoiding unused data field.
43 */
44 class MarkerSegment implements Cloneable {
45 protected static final int LENGTH_SIZE = 2; // length is 2 bytes
46 int tag; // See JPEG.java
47 int length; /* Sometimes needed by subclasses; doesn't include
48 itself. Meaningful only if constructed from a stream */
49 byte [] data = null; // Raw segment data, used for unrecognized segments
50 boolean unknown = false; // Set to true if the tag is not recognized
51
52 /**
53 * Constructor for creating <code>MarkerSegment</code>s by reading
54 * from an <code>ImageInputStream</code>.
55 */
56 MarkerSegment(JPEGBuffer buffer) throws IOException {
57
58 buffer.loadBuf(3); // tag plus length
59 tag = buffer.buf[buffer.bufPtr++] & 0xff;
60 length = (buffer.buf[buffer.bufPtr++] & 0xff) << 8;
61 length |= buffer.buf[buffer.bufPtr++] & 0xff;
62 length -= 2; // JPEG length includes itself, we don't
63 buffer.bufAvail -= 3;
64 // Now that we know the true length, ensure that we've got it,
65 // or at least a bufferful if length is too big.
66 buffer.loadBuf(length);
67 }
68
69 /**
70 * Constructor used when creating segments other than by
71 * reading them from a stream.
72 */
73 MarkerSegment(int tag) {
74 this.tag = tag;
75 length = 0;
76 }
77
78 /**
79 * Construct a MarkerSegment from an "unknown" DOM Node.
80 */
81 MarkerSegment(Node node) throws IIOInvalidTreeException {
82 // The type of node should have been verified already.
83 // get the attribute and assign it to the tag
84 tag = getAttributeValue(node,
85 null,
86 "MarkerTag",
87 0, 255,
88 true);
89 length = 0;
90 // get the user object and clone it to the data
91 if (node instanceof IIOMetadataNode) {
92 IIOMetadataNode iioNode = (IIOMetadataNode) node;
93 try {
94 data = (byte []) iioNode.getUserObject();
95 } catch (Exception e) {
96 IIOInvalidTreeException newGuy =
97 new IIOInvalidTreeException
98 ("Can't get User Object", node);
99 newGuy.initCause(e);
100 throw newGuy;
101 }
102 } else {
103 throw new IIOInvalidTreeException
104 ("Node must have User Object", node);
105 }
106 }
107
108 /**
109 * Deep copy of data array.
110 */
111 protected Object clone() {
112 MarkerSegment newGuy = null;
113 try {
114 newGuy = (MarkerSegment) super.clone();
115 } catch (CloneNotSupportedException e) {} // won't happen
116 if (this.data != null) {
117 newGuy.data = data.clone();
118 }
119 return newGuy;
120 }
121
122 /**
123 * We have determined that we don't know the type, so load
124 * the data using the length parameter.
125 */
126 void loadData(JPEGBuffer buffer) throws IOException {
127 data = new byte[length];
128 buffer.readData(data);
129 }
130
131 IIOMetadataNode getNativeNode() {
132 IIOMetadataNode node = new IIOMetadataNode("unknown");
133 node.setAttribute("MarkerTag", Integer.toString(tag));
134 node.setUserObject(data);
135
136 return node;
137 }
138
139 static int getAttributeValue(Node node,
140 NamedNodeMap attrs,
141 String name,
142 int min,
143 int max,
144 boolean required)
145 throws IIOInvalidTreeException {
146 if (attrs == null) {
147 attrs = node.getAttributes();
148 }
149 String valueString = attrs.getNamedItem(name).getNodeValue();
150 int value = -1;
151 if (valueString == null) {
152 if (required) {
153 throw new IIOInvalidTreeException
154 (name + " attribute not found", node);
155 }
156 } else {
157 value = Integer.parseInt(valueString);
158 if ((value < min) || (value > max)) {
159 throw new IIOInvalidTreeException
160 (name + " attribute out of range", node);
161 }
162 }
163 return value;
164 }
165
166 /**
167 * Writes the marker, tag, and length. Note that length
168 * should be verified by the caller as a correct JPEG
169 * length, i.e it includes itself.
170 */
171 void writeTag(ImageOutputStream ios) throws IOException {
172 ios.write(0xff);
173 ios.write(tag);
174 write2bytes(ios, length);
175 }
176
177 /**
178 * Writes the data for this segment to the stream in
179 * valid JPEG format.
180 */
181 void write(ImageOutputStream ios) throws IOException {
182 length = 2 + ((data != null) ? data.length : 0);
183 writeTag(ios);
184 if (data != null) {
185 ios.write(data);
186 }
187 }
188
189 static void write2bytes(ImageOutputStream ios,
190 int value) throws IOException {
191 ios.write((value >> 8) & 0xff);
192 ios.write(value & 0xff);
193
194 }
195
196 void printTag(String prefix) {
197 System.out.println(prefix + " marker segment - marker = 0x"
198 + Integer.toHexString(tag));
199 System.out.println("length: " + length);
200 }
201
202 void print() {
203 printTag("Unknown");
204 if (length > 10) {
205 System.out.print("First 5 bytes:");
206 for (int i=0;i<5;i++) {
207 System.out.print(" Ox"
208 + Integer.toHexString((int)data[i]));
209 }
210 System.out.print("\nLast 5 bytes:");
211 for (int i=data.length-5;i<data.length;i++) {
212 System.out.print(" Ox"
213 + Integer.toHexString((int)data[i]));
214 }
215 } else {
216 System.out.print("Data:");
217 for (int i=0;i<data.length;i++) {
218 System.out.print(" Ox"
219 + Integer.toHexString((int)data[i]));
220 }
221 }
222 System.out.println();
223 }
224 }