treilly 2004/05/30 23:54:24 Added: id/src/java/org/apache/commons/id/uuid Bytes.java Log: Class from turbine for Byte utilities convert to/from long, short Revision Changes Path 1.1 jakarta-commons-sandbox/id/src/java/org/apache/commons/id/uuid/Bytes.java Index: Bytes.java =================================================================== /* * Copyright 2003-2004 The Apache Software Foundation. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.id.uuid; /** * <p>Static methods for managing byte arrays (all methods follow Big * Endian order where most significant bits are in front).</p> * * @author Commons-Id Team * @version $Id: Bytes.java,v 1.1 2004/05/31 06:54:24 treilly Exp $ * [EMAIL PROTECTED] http://jakarta.apache.org/turbine/turbine-2.3/} */ public final class Bytes { /** * <p>Hide constructor in utility class.</p> */ private Bytes() { } /** * Appends two bytes array into one. * * @param a A byte[]. * @param b A byte[]. * @return A byte[]. */ public static byte[] append(byte[] a, byte[] b) { byte[] z = new byte[a.length + b.length]; System.arraycopy(a, 0, z, 0, a.length); System.arraycopy(b, 0, z, a.length, b.length); return z; } /** * Returns a 8-byte array built from a long. * * @param n The number to convert. * @return A byte[]. */ public static byte[] toBytes(long n) { return toBytes(n, new byte[8]); } /** * Build a 8-byte array from a long. No check is performed on the * array length. * * @param n The number to convert. * @param b The array to fill. * @return A byte[]. */ public static byte[] toBytes(long n, byte[] b) { b[7] = (byte) (n); n >>>= 8; b[6] = (byte) (n); n >>>= 8; b[5] = (byte) (n); n >>>= 8; b[4] = (byte) (n); n >>>= 8; b[3] = (byte) (n); n >>>= 8; b[2] = (byte) (n); n >>>= 8; b[1] = (byte) (n); n >>>= 8; b[0] = (byte) (n); return b; } /** * Build a long from first 8 bytes of the array. * * @param b The byte[] to convert. * @return A long. */ public static long toLong(byte[] b) { return ((((long) b[7]) & 0xFF) + ((((long) b[6]) & 0xFF) << 8) + ((((long) b[5]) & 0xFF) << 16) + ((((long) b[4]) & 0xFF) << 24) + ((((long) b[3]) & 0xFF) << 32) + ((((long) b[2]) & 0xFF) << 40) + ((((long) b[1]) & 0xFF) << 48) + ((((long) b[0]) & 0xFF) << 56)); } /** * Compares two byte arrays for equality. * * @param a A byte[]. * @param b A byte[]. * @return True if the arrays have identical contents. */ public static boolean areEqual(byte[] a, byte[] b) { int aLength = a.length; if (aLength != b.length) { return false; } for (int i = 0; i < aLength; i++) { if (a[i] != b[i]) { return false; } } return true; } /** * <p>Compares two byte arrays as specified by <code>Comparable</code>. * * @param lhs - left hand value in the comparison operation. * @param rhs - right hand value in the comparison operation. * @return a negative integer, zero, or a positive integer as <code>lhs</code> * is less than, equal to, or greater than <code>rhs</code>. */ public static int compareTo(byte[] lhs, byte[] rhs) { if (lhs == rhs) { return 0; } if (lhs == null) { return -1; } if (rhs == null) { return +1; } if (lhs.length != rhs.length) { return ((lhs.length < rhs.length) ? -1 : +1); } for (int i = 0; i < lhs.length; i++) { if (lhs[i] < rhs[i]) { return -1; } else if (lhs[i] > rhs[i]) { return 1; } } return 0; } /** * Build a short from first 2 bytes of the array. * * @param b The byte[] to convert. * @return A short. */ public static short toShort(byte[] b) { return (short) ((b[1] & 0xFF) + ((b[0] & 0xFF) << 8)); } }
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