1 /* BigDecimalHelper.java -- 2 Copyright (C) 2005 Free Software Foundation, Inc. 3 4 This file is part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; see the file COPYING. If not, write to the 18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301 USA. 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 39 package gnu.CORBA; 40 41 import gnu.java.lang.CPStringBuilder; 42 43 import java.io.ByteArrayInputStream; 44 import java.io.ByteArrayOutputStream; 45 import java.io.IOException; 46 47 import java.math.BigDecimal; 48 import java.math.BigInteger; 49 50 import org.omg.CORBA.TypeCodePackage.BadKind; 51 52 /** 53 * Reads and writes BigDecimal as CORBA <code>fixed</code>. 54 * The format, described in CORBA specification, requires to store 55 * data in hexadecimal format, two digits per byte (oceted), most 56 * significant digit first. The last half-byte in the representation 57 * stores the sign, being 0xD for negative numbers and 0xC for 58 * zero and positive numbers. To have the even number of half bytes, 59 * 0x0 is appended to the beginning, if required. The position of the 60 * decimal point is not stored. 61 * 62 * @author Audrius Meskauskas (AudriusA@Bioinformatics.org) 63 */ 64 public class BigDecimalHelper 65 { 66 { 67 } 68 69 /** 70 * @todo remove from the release version. 71 */ main(String[] args)72 public static void main(String[] args) 73 { 74 try 75 { 76 ByteArrayOutputStream b = new ByteArrayOutputStream(); 77 BigDecimal d = new BigDecimal("12234.54689"); 78 79 write(b, d); 80 81 byte[] a = b.toByteArray(); 82 83 for (int i = 0; i < a.length; i++) 84 { 85 int k = a [ i ] & 0xFF; 86 System.out.print(Integer.toHexString(k) + " "); 87 } 88 89 System.out.println("Now reading"); 90 91 ByteArrayInputStream bin = new ByteArrayInputStream(a); 92 93 BigDecimal r = read(bin, d.scale()); 94 95 System.out.println(r); 96 } 97 catch (Exception ex) 98 { 99 ex.printStackTrace(); 100 } 101 } 102 103 /** 104 * Read the CORBA fixed, autodetecting the number of bytes 105 * and assuming the given scale. 106 */ read(java.io.InputStream in, int scale)107 public static BigDecimal read(java.io.InputStream in, int scale) 108 throws IOException 109 { 110 ByteArrayOutputStream bout = new ByteArrayOutputStream(); 111 112 int f; 113 114 do 115 { 116 f = in.read(); 117 if (f >= 0) 118 bout.write(f); 119 } 120 // The last byte has 0xC or 0xD in the last halfbyte. 121 while ((f & 0xF) <= 0x9); 122 123 return createFixed(scale, bout.toByteArray()); 124 } 125 126 /** 127 * Write the big decimal as CORBA <code>fixed<.code>. 128 * The scale will not be stored. 129 * 130 * @param out a stream to write into. 131 * @param x a big decimal to write. 132 * 133 * @throws IOException if the stream write method throws one. 134 * @throws BadKind if this BigDecimal has more digits than 135 * specified. 136 */ write(java.io.OutputStream out, BigDecimal x)137 public static void write(java.io.OutputStream out, BigDecimal x) 138 throws IOException, BadKind 139 { 140 CPStringBuilder v = new CPStringBuilder(x.unscaledValue().toString()); 141 142 boolean negative = v.charAt(0) == '-'; 143 144 if (negative) 145 v = v.deleteCharAt(0); 146 147 if ( (v.length() & 1) == 0) 148 v.insert(0, '0'); 149 150 int c; 151 152 for (int i = 0; i < v.length() - 1; i = i + 2) 153 { 154 c = ((v.charAt(i) - '0') << 4) | (v.charAt(i + 1) - '0'); 155 out.write(c); 156 } 157 158 c = ((v.charAt(v.length() - 1) - '0') << 4) | (negative ? 0xD : 0xC); 159 160 out.write(c); 161 } 162 163 /** 164 * Convert the loaded byte array, representing 165 * CORBA <code>fixed</code>, into an instance of 166 * the {@link BigDecimal} 167 */ createFixed(int scale, byte[] d)168 private static BigDecimal createFixed(int scale, byte[] d) 169 { 170 CPStringBuilder s = new CPStringBuilder(2 * d.length); 171 172 int last = d.length - 1; 173 174 if ((d [ last ] & 0xF) == 0xD) 175 s.append('-'); 176 177 if (last > 0) 178 for (int i = 0; i < last; i++) 179 { 180 s.append((char) (((d [ i ] >> 4) & 0xF) + '0')); 181 s.append((char) (((d [ i ]) & 0xF) + '0')); 182 } 183 184 s.append((char) (((d [ last ] >> 4) & 0xF) + '0')); 185 186 BigInteger b = new BigInteger(s.toString()); 187 BigDecimal dec = new BigDecimal(b, scale); 188 189 return dec; 190 } 191 } 192