1 /*

     2  * Copyright (c) 2000, 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 import java.util.zip.CRC32;

    27 

    28 /**

    29  * Checksum provides methods for calculating a CRC32 value for a

    30  * transitions table.

    31  *

    32  * @since 1.4

    33  */

    34 public class Checksum extends CRC32

    35 {

    36     /**

    37      * Updates the CRC32 value from each byte of the given int

    38      * value. The bytes are used in the big endian order.

    39      * @param val the int value

    40      */

    41     public void update(int val) {

    42         byte[] b = new byte[4];

    43         b[0] = (byte)((val >>> 24) & 0xff);

    44         b[1] = (byte)((val >>> 16) & 0xff);

    45         b[2] = (byte)((val >>> 8) & 0xff);

    46         b[3] = (byte)(val & 0xff);

    47         update(b);

    48     }

    49 

    50     /**

    51      * Updates the CRC32 value from each byte of the given long

    52      * value. The bytes are used in the big endian order.

    53      * @param val the long value

    54      */

    55     void update(long val) {

    56         byte[] b = new byte[8];

    57         b[0] = (byte)((val >>> 56) & 0xff);

    58         b[1] = (byte)((val >>> 48) & 0xff);

    59         b[2] = (byte)((val >>> 40) & 0xff);

    60         b[3] = (byte)((val >>> 32) & 0xff);

    61         b[4] = (byte)((val >>> 24) & 0xff);

    62         b[5] = (byte)((val >>> 16) & 0xff);

    63         b[6] = (byte)((val >>> 8) & 0xff);

    64         b[7] = (byte)(val & 0xff);

    65         update(b);

    66     }

    67 }