- /* ====================================================================
- Licensed to the Apache Software Foundation (ASF) under one or more
- contributor license agreements. See the NOTICE file distributed with
- this work for additional information regarding copyright ownership.
- The ASF licenses this file to You 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.poi.ss.util;
-
-
- /**
- * Excel converts numbers to text with different rules to those of java, so
- * {@code Double.toString(value)} won't do.
- * <ul>
- * <li>No more than 15 significant figures are output (java does 18).</li>
- * <li>The sign char for the exponent is included even if positive</li>
- * <li>Special values ({@code NaN} and {@code Infinity}) get rendered like the ordinary
- * number that the bit pattern represents.</li>
- * <li>Denormalised values (between ±2<sup>-1074</sup> and ±2<sup>-1022</sup>
- * are displayed as "0"</li>
- * </ul>
- * IEEE 64-bit Double Rendering Comparison
- *
- * <table>
- * <caption>IEEE 64-bit Double Rendering Comparison</caption>
- * <tr><th>Raw bits</th><th>Java</th><th>Excel</th></tr>
- *
- * <tr><td>0x0000000000000000L</td><td>0.0</td><td>0</td></tr>
- * <tr><td>0x3FF0000000000000L</td><td>1.0</td><td>1</td></tr>
- * <tr><td>0x3FF00068DB8BAC71L</td><td>1.0001</td><td>1.0001</td></tr>
- * <tr><td>0x4087A00000000000L</td><td>756.0</td><td>756</td></tr>
- * <tr><td>0x401E3D70A3D70A3DL</td><td>7.56</td><td>7.56</td></tr>
- * <tr><td>0x405EDD3C07FB4C99L</td><td>123.45678901234568</td><td>123.456789012346</td></tr>
- * <tr><td>0x4132D687E3DF2180L</td><td>1234567.8901234567</td><td>1234567.89012346</td></tr>
- * <tr><td>0x3EE9E409302678BAL</td><td>1.2345678901234568E-5</td><td>1.23456789012346E-05</td></tr>
- * <tr><td>0x3F202E85BE180B74L</td><td>1.2345678901234567E-4</td><td>0.000123456789012346</td></tr>
- * <tr><td>0x3F543A272D9E0E51L</td><td>0.0012345678901234567</td><td>0.00123456789012346</td></tr>
- * <tr><td>0x3F8948B0F90591E6L</td><td>0.012345678901234568</td><td>0.0123456789012346</td></tr>
- * <tr><td>0x3EE9E409301B5A02L</td><td>1.23456789E-5</td><td>0.0000123456789</td></tr>
- * <tr><td>0x3E6E7D05BDABDE50L</td><td>5.6789012345E-8</td><td>0.000000056789012345</td></tr>
- * <tr><td>0x3E6E7D05BDAD407EL</td><td>5.67890123456E-8</td><td>5.67890123456E-08</td></tr>
- * <tr><td>0x3E6E7D06029F18BEL</td><td>5.678902E-8</td><td>0.00000005678902</td></tr>
- * <tr><td>0x2BCB5733CB32AE6EL</td><td>9.999999999999123E-98</td><td>9.99999999999912E-98</td></tr>
- * <tr><td>0x2B617F7D4ED8C59EL</td><td>1.0000000000001235E-99</td><td>1.0000000000001E-99</td></tr>
- * <tr><td>0x0036319916D67853L</td><td>1.2345678901234578E-307</td><td>1.2345678901235E-307</td></tr>
- * <tr><td>0x359DEE7A4AD4B81FL</td><td>2.0E-50</td><td>2E-50</td></tr>
- * <tr><td>0x41678C29DCD6E9E0L</td><td>1.2345678901234567E7</td><td>12345678.9012346</td></tr>
- * <tr><td>0x42A674E79C5FE523L</td><td>1.2345678901234568E13</td><td>12345678901234.6</td></tr>
- * <tr><td>0x42DC12218377DE6BL</td><td>1.2345678901234567E14</td><td>123456789012346</td></tr>
- * <tr><td>0x43118B54F22AEB03L</td><td>1.2345678901234568E15</td><td>1234567890123460</td></tr>
- * <tr><td>0x43E56A95319D63E1L</td><td>1.2345678901234567E19</td><td>12345678901234600000</td></tr>
- * <tr><td>0x441AC53A7E04BCDAL</td><td>1.2345678901234568E20</td><td>1.23456789012346E+20</td></tr>
- * <tr><td>0xC3E56A95319D63E1L</td><td>-1.2345678901234567E19</td><td>-12345678901234600000</td></tr>
- * <tr><td>0xC41AC53A7E04BCDAL</td><td>-1.2345678901234568E20</td><td>-1.23456789012346E+20</td></tr>
- * <tr><td>0x54820FE0BA17F46DL</td><td>1.2345678901234577E99</td><td>1.2345678901235E+99</td></tr>
- * <tr><td>0x54B693D8E89DF188L</td><td>1.2345678901234576E100</td><td>1.2345678901235E+100</td></tr>
- * <tr><td>0x4A611B0EC57E649AL</td><td>2.0E50</td><td>2E+50</td></tr>
- * <tr><td>0x7FEFFFFFFFFFFFFFL</td><td>1.7976931348623157E308</td><td>1.7976931348623E+308</td></tr>
- * <tr><td>0x0010000000000000L</td><td>2.2250738585072014E-308</td><td>2.2250738585072E-308</td></tr>
- * <tr><td>0x000FFFFFFFFFFFFFL</td><td>2.225073858507201E-308</td><td>0</td></tr>
- * <tr><td>0x0000000000000001L</td><td>4.9E-324</td><td>0</td></tr>
- * <tr><td>0x7FF0000000000000L</td><td>Infinity</td><td>1.7976931348623E+308</td></tr>
- * <tr><td>0xFFF0000000000000L</td><td>-Infinity</td><td>1.7976931348623E+308</td></tr>
- * <tr><td>0x441AC7A08EAD02F2L</td><td>1.234999999999999E20</td><td>1.235E+20</td></tr>
- * <tr><td>0x40FE26BFFFFFFFF9L</td><td>123499.9999999999</td><td>123500</td></tr>
- * <tr><td>0x3E4A857BFB2F2809L</td><td>1.234999999999999E-8</td><td>0.00000001235</td></tr>
- * <tr><td>0x3BCD291DEF868C89L</td><td>1.234999999999999E-20</td><td>1.235E-20</td></tr>
- * <tr><td>0x444B1AE4D6E2EF4FL</td><td>9.999999999999999E20</td><td>1E+21</td></tr>
- * <tr><td>0x412E847FFFFFFFFFL</td><td>999999.9999999999</td><td>1000000</td></tr>
- * <tr><td>0x3E45798EE2308C39L</td><td>9.999999999999999E-9</td><td>0.00000001</td></tr>
- * <tr><td>0x3C32725DD1D243ABL</td><td>9.999999999999999E-19</td><td>0.000000000000000001</td></tr>
- * <tr><td>0x3BFD83C94FB6D2ABL</td><td>9.999999999999999E-20</td><td>1E-19</td></tr>
- * <tr><td>0xC44B1AE4D6E2EF4FL</td><td>-9.999999999999999E20</td><td>-1E+21</td></tr>
- * <tr><td>0xC12E847FFFFFFFFFL</td><td>-999999.9999999999</td><td>-1000000</td></tr>
- * <tr><td>0xBE45798EE2308C39L</td><td>-9.999999999999999E-9</td><td>-0.00000001</td></tr>
- * <tr><td>0xBC32725DD1D243ABL</td><td>-9.999999999999999E-19</td><td>-0.000000000000000001</td></tr>
- * <tr><td>0xBBFD83C94FB6D2ABL</td><td>-9.999999999999999E-20</td><td>-1E-19</td></tr>
- * <tr><td>0xFFFF0420003C0000L</td><td>NaN</td><td>3.484840871308E+308</td></tr>
- * <tr><td>0x7FF8000000000000L</td><td>NaN</td><td>2.6965397022935E+308</td></tr>
- * <tr><td>0x7FFF0420003C0000L</td><td>NaN</td><td>3.484840871308E+308</td></tr>
- * <tr><td>0xFFF8000000000000L</td><td>NaN</td><td>2.6965397022935E+308</td></tr>
- * <tr><td>0xFFFF0AAAAAAAAAAAL</td><td>NaN</td><td>3.4877119413344E+308</td></tr>
- * <tr><td>0x7FF80AAAAAAAAAAAL</td><td>NaN</td><td>2.7012211948322E+308</td></tr>
- * <tr><td>0xFFFFFFFFFFFFFFFFL</td><td>NaN</td><td>3.5953862697246E+308</td></tr>
- * <tr><td>0x7FFFFFFFFFFFFFFFL</td><td>NaN</td><td>3.5953862697246E+308</td></tr>
- * <tr><td>0xFFF7FFFFFFFFFFFFL</td><td>NaN</td><td>2.6965397022935E+308</td></tr>
- * </table>
- *
- * <b>Note</b>:
- * Excel has inconsistent rules for the following numeric operations:
- * <ul>
- * <li>Conversion to string (as handled here)</li>
- * <li>Rendering numerical quantities in the cell grid.</li>
- * <li>Conversion from text</li>
- * <li>General arithmetic</li>
- * </ul>
- * Excel's text to number conversion is not a true <i>inverse</i> of this operation. The
- * allowable ranges are different. Some numbers that don't correctly convert to text actually
- * <b>do</b> get handled properly when used in arithmetic evaluations.
- */
- public final class NumberToTextConverter {
-
- private static final long EXCEL_NAN_BITS = 0xFFFF0420003C0000L;
- private static final int MAX_TEXT_LEN = 20;
-
- private NumberToTextConverter() {
- // no instances of this class
- }
-
- /**
- * Converts the supplied {@code value} to the text representation that Excel would give if
- * the value were to appear in an unformatted cell, or as a literal number in a formula.<br>
- * Note - the results from this method differ slightly from those of {@code Double.toString()}
- * In some special cases Excel behaves quite differently. This function attempts to reproduce
- * those results.
- */
- public static String toText(double value) {
- return rawDoubleBitsToText(Double.doubleToLongBits(value));
- }
- /* package */ static String rawDoubleBitsToText(long pRawBits) {
-
- long rawBits = pRawBits;
- boolean isNegative = rawBits < 0; // sign bit is in the same place for long and double
- if (isNegative) {
- rawBits &= 0x7FFFFFFFFFFFFFFFL;
- }
- if (rawBits == 0) {
- return isNegative ? "-0" : "0";
- }
- ExpandedDouble ed = new ExpandedDouble(rawBits);
- if (ed.getBinaryExponent() < -1022) {
- // value is 'denormalised' which means it is less than 2^-1022
- // excel displays all these numbers as zero, even though calculations work OK
- return isNegative ? "-0" : "0";
- }
- if (ed.getBinaryExponent() == 1024) {
- // Special number NaN /Infinity
- // Normally one would not create HybridDecimal objects from these values
- // except in these cases Excel really tries to render them as if they were normal numbers
- if(rawBits == EXCEL_NAN_BITS) {
- return "3.484840871308E+308";
- }
- // This is where excel really gets it wrong
- // Special numbers like Infinity and NaN are interpreted according to
- // the standard rules below.
- isNegative = false; // except that the sign bit is ignored
- }
- NormalisedDecimal nd = ed.normaliseBaseTen();
- StringBuilder sb = new StringBuilder(MAX_TEXT_LEN+1);
- if (isNegative) {
- sb.append('-');
- }
- convertToText(sb, nd);
- return sb.toString();
- }
- private static void convertToText(StringBuilder sb, NormalisedDecimal pnd) {
- NormalisedDecimal rnd = pnd.roundUnits();
- int decExponent = rnd.getDecimalExponent();
- String decimalDigits;
- if (Math.abs(decExponent)>98) {
- decimalDigits = rnd.getSignificantDecimalDigitsLastDigitRounded();
- if (decimalDigits.length() == 16) {
- // rounding caused carry
- decExponent++;
- }
- } else {
- decimalDigits = rnd.getSignificantDecimalDigits();
- }
- int countSigDigits = countSignifantDigits(decimalDigits);
- if (decExponent < 0) {
- formatLessThanOne(sb, decimalDigits, decExponent, countSigDigits);
- } else {
- formatGreaterThanOne(sb, decimalDigits, decExponent, countSigDigits);
- }
- }
-
- private static void formatLessThanOne(StringBuilder sb, String decimalDigits, int decExponent,
- int countSigDigits) {
- int nLeadingZeros = -decExponent - 1;
- int normalLength = 2 + nLeadingZeros + countSigDigits; // 2 == "0.".length()
-
- if (needsScientificNotation(normalLength)) {
- sb.append(decimalDigits.charAt(0));
- if (countSigDigits > 1) {
- sb.append('.');
- sb.append(decimalDigits.subSequence(1, countSigDigits));
- }
- sb.append("E-");
- appendExp(sb, -decExponent);
- return;
- }
- sb.append("0.");
- for (int i=nLeadingZeros; i>0; i--) {
- sb.append('0');
- }
- sb.append(decimalDigits.subSequence(0, countSigDigits));
- }
-
- private static void formatGreaterThanOne(StringBuilder sb, String decimalDigits, int decExponent, int countSigDigits) {
-
- if (decExponent > 19) {
- // scientific notation
- sb.append(decimalDigits.charAt(0));
- if (countSigDigits>1) {
- sb.append('.');
- sb.append(decimalDigits.subSequence(1, countSigDigits));
- }
- sb.append("E+");
- appendExp(sb, decExponent);
- return;
- }
- int nFractionalDigits = countSigDigits - decExponent - 1;
- if (nFractionalDigits > 0) {
- sb.append(decimalDigits.subSequence(0, decExponent+1));
- sb.append('.');
- sb.append(decimalDigits.subSequence(decExponent+1, countSigDigits));
- return;
- }
- sb.append(decimalDigits.subSequence(0, countSigDigits));
- for (int i=-nFractionalDigits; i>0; i--) {
- sb.append('0');
- }
- }
-
- private static boolean needsScientificNotation(int nDigits) {
- return nDigits > MAX_TEXT_LEN;
- }
-
- private static int countSignifantDigits(String sb) {
- int result=sb.length()-1;
- while(sb.charAt(result) == '0') {
- result--;
- if(result < 0) {
- throw new RuntimeException("No non-zero digits found");
- }
- }
- return result + 1;
- }
-
- private static void appendExp(StringBuilder sb, int val) {
- if(val < 10) {
- sb.append('0');
- sb.append((char)('0' + val));
- return;
- }
- sb.append(val);
- }
- }
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