Java tutorial
/* Copyright 2007 Creare Inc. 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. */ /* ***************************************************************** *** *** *** Name : ByteConvert () *** *** By : Eric Friets (Creare Inc., Hanover, NH) *** *** For : FlyScan,DoeScan *** *** Date : December 1997,July 2000 *** *** *** *** Copyright 1997-2000 Creare Inc. *** *** *** *** Description : extracts doubles, floats, short ints from *** *** byte arrays without using input streams, *** *** and vice-versa *** *** *** *** Input : primitive array *** *** *** *** Input/Output : *** *** *** *** Output : *** *** *** *** Returns : primitive array *** *** *** ***************************************************************** */ // all methods are static // using ByteArrayInputStream, DataInputStream, ByteArrayOutputStream, // and DataOutputStream are too slow; code for direct reads/writes // based on routines in the JVM ObjectInputStream and ObjectOutputStream // source files //package com.rbnb.utility; /** * Utility class to convert low level data types to and from byte arrays. */ // // 02/17/2003 WHF Added optional byte swapping on x2Byte methods. // public class ByteConvert { // byte2Double method - extracts doubles from byte array public static final double[] byte2Double(byte[] inData, boolean byteSwap) { int j = 0, upper, lower; int length = inData.length / 8; double[] outData = new double[length]; if (!byteSwap) for (int i = 0; i < length; i++) { j = i * 8; upper = (((inData[j] & 0xff) << 24) + ((inData[j + 1] & 0xff) << 16) + ((inData[j + 2] & 0xff) << 8) + ((inData[j + 3] & 0xff) << 0)); lower = (((inData[j + 4] & 0xff) << 24) + ((inData[j + 5] & 0xff) << 16) + ((inData[j + 6] & 0xff) << 8) + ((inData[j + 7] & 0xff) << 0)); outData[i] = Double.longBitsToDouble((((long) upper) << 32) + (lower & 0xffffffffl)); } else for (int i = 0; i < length; i++) { j = i * 8; upper = (((inData[j + 7] & 0xff) << 24) + ((inData[j + 6] & 0xff) << 16) + ((inData[j + 5] & 0xff) << 8) + ((inData[j + 4] & 0xff) << 0)); lower = (((inData[j + 3] & 0xff) << 24) + ((inData[j + 2] & 0xff) << 16) + ((inData[j + 1] & 0xff) << 8) + ((inData[j] & 0xff) << 0)); outData[i] = Double.longBitsToDouble((((long) upper) << 32) + (lower & 0xffffffffl)); } return outData; } }