View Javadoc
1   /*
2    * Copyright (c) 1999, 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 javax.imageio.stream;
27  
28  /**
29   * A class representing a mutable reference to an array of bytes and
30   * an offset and length within that array.  <code>IIOByteBuffer</code>
31   * is used by <code>ImageInputStream</code> to supply a sequence of bytes
32   * to the caller, possibly with fewer copies than using the conventional
33   * <code>read</code> methods that take a user-supplied byte array.
34   *
35   * <p> The byte array referenced by an <code>IIOByteBuffer</code> will
36   * generally be part of an internal data structure belonging to an
37   * <code>ImageReader</code> implementation; its contents should be
38   * considered read-only and must not be modified.
39   *
40   */
41  public class IIOByteBuffer {
42  
43      private byte[] data;
44  
45      private int offset;
46  
47      private int length;
48  
49      /**
50       * Constructs an <code>IIOByteBuffer</code> that references a
51       * given byte array, offset, and length.
52       *
53       * @param data a byte array.
54       * @param offset an int offset within the array.
55       * @param length an int specifying the length of the data of
56       * interest within byte array, in bytes.
57       */
58      public IIOByteBuffer(byte[] data, int offset, int length) {
59          this.data = data;
60          this.offset = offset;
61          this.length = length;
62      }
63  
64      /**
65       * Returns a reference to the byte array.  The returned value should
66       * be treated as read-only, and only the portion specified by the
67       * values of <code>getOffset</code> and <code>getLength</code> should
68       * be used.
69       *
70       * @return a byte array reference.
71       *
72       * @see #getOffset
73       * @see #getLength
74       * @see #setData
75       */
76      public byte[] getData() {
77          return data;
78      }
79  
80      /**
81       * Updates the array reference that will be returned by subsequent calls
82       * to the <code>getData</code> method.
83       *
84       * @param data a byte array reference containing the new data value.
85       *
86       * @see #getData
87       */
88      public void setData(byte[] data) {
89          this.data = data;
90      }
91  
92      /**
93       * Returns the offset within the byte array returned by
94       * <code>getData</code> at which the data of interest start.
95       *
96       * @return an int offset.
97       *
98       * @see #getData
99       * @see #getLength
100      * @see #setOffset
101      */
102     public int getOffset() {
103         return offset;
104     }
105 
106     /**
107      * Updates the value that will be returned by subsequent calls
108      * to the <code>getOffset</code> method.
109      *
110      * @param offset an int containing the new offset value.
111      *
112      * @see #getOffset
113      */
114     public void setOffset(int offset) {
115         this.offset = offset;
116     }
117 
118     /**
119      * Returns the length of the data of interest within the byte
120      * array returned by <code>getData</code>.
121      *
122      * @return an int length.
123      *
124      * @see #getData
125      * @see #getOffset
126      * @see #setLength
127      */
128     public int getLength() {
129         return length;
130     }
131 
132     /**
133      * Updates the value that will be returned by subsequent calls
134      * to the <code>getLength</code> method.
135      *
136      * @param length an int containing the new length value.
137      *
138      * @see #getLength
139      */
140     public void setLength(int length) {
141         this.length = length;
142     }
143 }