1 /*

     2  * Copyright (c) 2001, 2017, 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.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 /*

    25  * @test

    26  * @bug 4416800

    27  * @summary Checks that ImageInputStreamImpl.readBit and readBits handle the bit

    28  *          offset correctly

    29  */

    30 

    31 import java.io.ByteArrayInputStream;

    32 import java.io.IOException;

    33 import java.io.InputStream;

    34 

    35 import javax.imageio.stream.FileCacheImageInputStream;

    36 import javax.imageio.stream.ImageInputStream;

    37 

    38 public class ReadBitsTest {

    39     public static void main(String[] args) throws IOException {

    40         byte[] buffer = new byte[] {(byte)169, (byte)85}; // 10101001 01010101

    41         InputStream ins = new ByteArrayInputStream(buffer);

    42         ImageInputStream in = new FileCacheImageInputStream(ins,null);

    43 

    44         if (in.getBitOffset() != 0) {

    45             throw new RuntimeException("Initial bit offset != 0!");

    46         }

    47 

    48         int bit0 = in.readBit(); // 1

    49         if (bit0 != 1) {

    50             throw new RuntimeException("First bit != 1");

    51         }

    52         if (in.getBitOffset() != 1) {

    53             throw new RuntimeException("Second bit offset != 1");

    54         }

    55 

    56         long bits1 = in.readBits(5); // 01010 = 10

    57         if (bits1 != 10) {

    58             throw new RuntimeException("Bits 1-5 != 10 (= " + bits1 + ")");

    59         }

    60         if (in.getBitOffset() != 6) {

    61             throw new RuntimeException("Third bit offset != 6");

    62         }

    63 

    64         int bit1 = in.readBit(); // 0

    65         if (bit1 != 0) {

    66             throw new RuntimeException("Bit 6 != 0");

    67         }

    68         if (in.getBitOffset() != 7) {

    69             throw new RuntimeException("Third bit offset != 7");

    70         }

    71 

    72         long bits2 = in.readBits(8); // 10101010 = 170

    73         if (bits2 != 170) {

    74             throw new RuntimeException("Bits 7-14 != 170 (= " + bits2 + ")");

    75         }

    76         if (in.getBitOffset() != 7) {

    77             throw new RuntimeException("Fourth bit offset != 7");

    78         }

    79 

    80         int bit2 = in.readBit(); // 1

    81         if (bit2 != 1) {

    82             throw new RuntimeException("Bit 15 != 1");

    83         }

    84         if (in.getBitOffset() != 0) {

    85             throw new RuntimeException("Fifth bit offset != 0");

    86         }

    87 

    88         in.close();

    89     }

    90 }