| /* |
| * 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.usermodel; |
| import java.text.FieldPosition; |
| import java.text.Format; |
| import java.text.ParsePosition; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| import org.apache.poi.ss.format.SimpleFraction; |
| import org.apache.poi.ss.formula.eval.NotImplementedException; |
| import org.apache.poi.util.POILogFactory; |
| import org.apache.poi.util.POILogger; |
| |
| /** |
| * <p>Format class that handles Excel style fractions, such as "# #/#" and "#/###"</p> |
| * |
| * <p>As of this writing, this is still not 100% accurate, but it does a reasonable job |
| * of trying to mimic Excel's fraction calculations. It does not currently |
| * maintain Excel's spacing.</p> |
| * |
| * <p>This class relies on a method lifted nearly verbatim from org.apache.math.fraction. |
| * If further uses for Commons Math are found, we will consider adding it as a dependency. |
| * For now, we have in-lined the one method to keep things simple.</p> |
| */ |
| |
| @SuppressWarnings("serial") |
| public class FractionFormat extends Format { |
| private static final POILogger LOGGER = POILogFactory.getLogger(FractionFormat.class); |
| private static final Pattern DENOM_FORMAT_PATTERN = Pattern.compile("(?:(#+)|(\\d+))"); |
| |
| //this was chosen to match the earlier limitation of max denom power |
| //it can be expanded to get closer to Excel's calculations |
| //with custom formats # #/######### |
| //but as of this writing, the numerators and denominators |
| //with formats of that nature on very small values were quite |
| //far from Excel's calculations |
| private static final int MAX_DENOM_POW = 4; |
| |
| //there are two options: |
| //a) an exact denominator is specified in the formatString |
| //b) the maximum denominator can be calculated from the formatString |
| private final int exactDenom; |
| private final int maxDenom; |
| |
| private final String wholePartFormatString; |
| /** |
| * Single parameter ctor |
| * @param denomFormatString The format string for the denominator |
| */ |
| public FractionFormat(String wholePartFormatString, String denomFormatString) { |
| this.wholePartFormatString = wholePartFormatString; |
| //init exactDenom and maxDenom |
| Matcher m = DENOM_FORMAT_PATTERN.matcher(denomFormatString); |
| int tmpExact = -1; |
| int tmpMax = -1; |
| if (m.find()){ |
| if (m.group(2) != null){ |
| try{ |
| tmpExact = Integer.parseInt(m.group(2)); |
| //if the denom is 0, fall back to the default: tmpExact=100 |
| |
| if (tmpExact == 0){ |
| tmpExact = -1; |
| } |
| } catch (NumberFormatException e){ |
| //should never happen |
| } |
| } else if (m.group(1) != null) { |
| int len = m.group(1).length(); |
| len = len > MAX_DENOM_POW ? MAX_DENOM_POW : len; |
| tmpMax = (int)Math.pow(10, len); |
| } else { |
| tmpExact = 100; |
| } |
| } |
| if (tmpExact <= 0 && tmpMax <= 0){ |
| //use 100 as the default denom if something went horribly wrong |
| tmpExact = 100; |
| } |
| exactDenom = tmpExact; |
| maxDenom = tmpMax; |
| } |
| |
| public String format(Number num) { |
| |
| final double doubleValue = num.doubleValue(); |
| |
| final boolean isNeg = (doubleValue < 0.0f) ? true : false; |
| final double absDoubleValue = Math.abs(doubleValue); |
| |
| final double wholePart = Math.floor(absDoubleValue); |
| final double decPart = absDoubleValue - wholePart; |
| if (wholePart + decPart == 0) { |
| return "0"; |
| } |
| |
| // if the absolute value is smaller than 1 over the exact or maxDenom |
| // you can stop here and return "0" |
| // reciprocal is result of an int devision ... and so it's nearly always 0 |
| // double reciprocal = 1/Math.max(exactDenom, maxDenom); |
| // if (absDoubleValue < reciprocal) { |
| // return "0"; |
| // } |
| |
| //this is necessary to prevent overflow in the maxDenom calculation |
| if (Double.compare(decPart, 0) == 0){ |
| |
| StringBuilder sb = new StringBuilder(); |
| if (isNeg){ |
| sb.append("-"); |
| } |
| sb.append((int)wholePart); |
| return sb.toString(); |
| } |
| |
| SimpleFraction fract = null; |
| try{ |
| //this should be the case because of the constructor |
| if (exactDenom > 0){ |
| fract = SimpleFraction.buildFractionExactDenominator(decPart, exactDenom); |
| } else { |
| fract = SimpleFraction.buildFractionMaxDenominator(decPart, maxDenom); |
| } |
| } catch (RuntimeException e){ |
| LOGGER.log(POILogger.WARN, "Can't format fraction", e); |
| return Double.toString(doubleValue); |
| } |
| |
| StringBuilder sb = new StringBuilder(); |
| |
| //now format the results |
| if (isNeg){ |
| sb.append("-"); |
| } |
| |
| //if whole part has to go into the numerator |
| if (wholePartFormatString == null || wholePartFormatString.isEmpty()){ |
| int trueNum = (fract.getDenominator()*(int)wholePart)+fract.getNumerator(); |
| sb.append(trueNum).append("/").append(fract.getDenominator()); |
| return sb.toString(); |
| } |
| |
| |
| //short circuit if fraction is 0 or 1 |
| if (fract.getNumerator() == 0){ |
| sb.append(Integer.toString((int)wholePart)); |
| return sb.toString(); |
| } else if (fract.getNumerator() == fract.getDenominator()){ |
| sb.append(Integer.toString((int)wholePart+1)); |
| return sb.toString(); |
| } |
| //as mentioned above, this ignores the exact space formatting in Excel |
| if (wholePart > 0){ |
| sb.append(Integer.toString((int)wholePart)).append(" "); |
| } |
| sb.append(fract.getNumerator()).append("/").append(fract.getDenominator()); |
| return sb.toString(); |
| } |
| |
| public StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition pos) { |
| return toAppendTo.append(format((Number)obj)); |
| } |
| |
| public Object parseObject(String source, ParsePosition pos) { |
| throw new NotImplementedException("Reverse parsing not supported"); |
| } |
| |
| } |