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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: */ 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: */ 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: */ 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: */ 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: }