001 /*
002 * Copyright 2001-2005 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.io;
027
028 /**
029 * Utility methods for packing/unpacking primitive values in/out of byte arrays
030 * using big-endian byte ordering.
031 */
032 class Bits {
033
034 /*
035 * Methods for unpacking primitive values from byte arrays starting at
036 * given offsets.
037 */
038
039 static boolean getBoolean(byte[] b, int off) {
040 return b[off] != 0;
041 }
042
043 static char getChar(byte[] b, int off) {
044 return (char) (((b[off + 1] & 0xFF) << 0) + ((b[off + 0]) << 8));
045 }
046
047 static short getShort(byte[] b, int off) {
048 return (short) (((b[off + 1] & 0xFF) << 0) + ((b[off + 0]) << 8));
049 }
050
051 static int getInt(byte[] b, int off) {
052 return ((b[off + 3] & 0xFF) << 0) + ((b[off + 2] & 0xFF) << 8)
053 + ((b[off + 1] & 0xFF) << 16) + ((b[off + 0]) << 24);
054 }
055
056 static float getFloat(byte[] b, int off) {
057 int i = ((b[off + 3] & 0xFF) << 0) + ((b[off + 2] & 0xFF) << 8)
058 + ((b[off + 1] & 0xFF) << 16) + ((b[off + 0]) << 24);
059 return Float.intBitsToFloat(i);
060 }
061
062 static long getLong(byte[] b, int off) {
063 return ((b[off + 7] & 0xFFL) << 0)
064 + ((b[off + 6] & 0xFFL) << 8)
065 + ((b[off + 5] & 0xFFL) << 16)
066 + ((b[off + 4] & 0xFFL) << 24)
067 + ((b[off + 3] & 0xFFL) << 32)
068 + ((b[off + 2] & 0xFFL) << 40)
069 + ((b[off + 1] & 0xFFL) << 48)
070 + (((long) b[off + 0]) << 56);
071 }
072
073 static double getDouble(byte[] b, int off) {
074 long j = ((b[off + 7] & 0xFFL) << 0)
075 + ((b[off + 6] & 0xFFL) << 8)
076 + ((b[off + 5] & 0xFFL) << 16)
077 + ((b[off + 4] & 0xFFL) << 24)
078 + ((b[off + 3] & 0xFFL) << 32)
079 + ((b[off + 2] & 0xFFL) << 40)
080 + ((b[off + 1] & 0xFFL) << 48)
081 + (((long) b[off + 0]) << 56);
082 return Double.longBitsToDouble(j);
083 }
084
085 /*
086 * Methods for packing primitive values into byte arrays starting at given
087 * offsets.
088 */
089
090 static void putBoolean(byte[] b, int off, boolean val) {
091 b[off] = (byte) (val ? 1 : 0);
092 }
093
094 static void putChar(byte[] b, int off, char val) {
095 b[off + 1] = (byte) (val >>> 0);
096 b[off + 0] = (byte) (val >>> 8);
097 }
098
099 static void putShort(byte[] b, int off, short val) {
100 b[off + 1] = (byte) (val >>> 0);
101 b[off + 0] = (byte) (val >>> 8);
102 }
103
104 static void putInt(byte[] b, int off, int val) {
105 b[off + 3] = (byte) (val >>> 0);
106 b[off + 2] = (byte) (val >>> 8);
107 b[off + 1] = (byte) (val >>> 16);
108 b[off + 0] = (byte) (val >>> 24);
109 }
110
111 static void putFloat(byte[] b, int off, float val) {
112 int i = Float.floatToIntBits(val);
113 b[off + 3] = (byte) (i >>> 0);
114 b[off + 2] = (byte) (i >>> 8);
115 b[off + 1] = (byte) (i >>> 16);
116 b[off + 0] = (byte) (i >>> 24);
117 }
118
119 static void putLong(byte[] b, int off, long val) {
120 b[off + 7] = (byte) (val >>> 0);
121 b[off + 6] = (byte) (val >>> 8);
122 b[off + 5] = (byte) (val >>> 16);
123 b[off + 4] = (byte) (val >>> 24);
124 b[off + 3] = (byte) (val >>> 32);
125 b[off + 2] = (byte) (val >>> 40);
126 b[off + 1] = (byte) (val >>> 48);
127 b[off + 0] = (byte) (val >>> 56);
128 }
129
130 static void putDouble(byte[] b, int off, double val) {
131 long j = Double.doubleToLongBits(val);
132 b[off + 7] = (byte) (j >>> 0);
133 b[off + 6] = (byte) (j >>> 8);
134 b[off + 5] = (byte) (j >>> 16);
135 b[off + 4] = (byte) (j >>> 24);
136 b[off + 3] = (byte) (j >>> 32);
137 b[off + 2] = (byte) (j >>> 40);
138 b[off + 1] = (byte) (j >>> 48);
139 b[off + 0] = (byte) (j >>> 56);
140 }
141 }
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