001 /** 002 * ========================================= 003 * LibFormula : a free Java formula library 004 * ========================================= 005 * 006 * Project Info: http://reporting.pentaho.org/libformula/ 007 * 008 * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors. 009 * 010 * This library is free software; you can redistribute it and/or modify it under the terms 011 * of the GNU Lesser General Public License as published by the Free Software Foundation; 012 * either version 2.1 of the License, or (at your option) any later version. 013 * 014 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 015 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 016 * See the GNU Lesser General Public License for more details. 017 * 018 * You should have received a copy of the GNU Lesser General Public License along with this 019 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, 020 * Boston, MA 02111-1307, USA. 021 * 022 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 023 * in the United States and other countries.] 024 * 025 * 026 * ------------ 027 * $Id: DateDifFunction.java 2716 2007-04-01 13:51:58Z taqua $ 028 * ------------ 029 * (C) Copyright 2006-2007, by Pentaho Corporation. 030 */ 031 package org.jfree.formula.function.datetime; 032 033 import java.util.Calendar; 034 import java.util.Date; 035 import java.util.GregorianCalendar; 036 import java.util.Locale; 037 import java.util.TimeZone; 038 039 import org.jfree.formula.EvaluationException; 040 import org.jfree.formula.FormulaContext; 041 import org.jfree.formula.LibFormulaErrorValue; 042 import org.jfree.formula.LocalizationContext; 043 import org.jfree.formula.function.Function; 044 import org.jfree.formula.function.ParameterCallback; 045 import org.jfree.formula.lvalues.TypeValuePair; 046 import org.jfree.formula.typing.TypeRegistry; 047 import org.jfree.formula.typing.coretypes.NumberType; 048 049 /** 050 * This function returns the number of years, months, or days between two date 051 * numbers.<br/> 052 * <p/> 053 * The Format is a code from the following table, entered as text, that 054 * specifies the format you want: <TABLE> <TR> <TH>format</TH> <TH>Returns the 055 * number of</TH> </TR> <TR> <TD>y</TD> <TD>Years</TD> </TR> <TR> <TD>m</TD> 056 * <TD>Months. If there is not a complete month between the dates, 0 will be 057 * returned.</TD> </TR> <TR> <TD>d</TD> <TD>Days</TD> </TR> <TR> <TD>md</TD> 058 * <TD>Days, ignoring months and years</TD> </TR> <TR> <TD>ym</TD> <TD>Months, 059 * ignoring years</TD> </TR> <TR> <TD>yd</TD> <TD>Days, ignoring years</TD> 060 * </TR> <TR> <TD></TD> <TD></TD> </TR> </TABLE> 061 * 062 * @author Cedric Pronzato 063 */ 064 public class DateDifFunction implements Function 065 { 066 public static final String YEARS_CODE = "y"; 067 public static final String MONTHS_CODE = "m"; 068 public static final String DAYS_CODE = "d"; 069 public static final String DAYS_IGNORING_YEARS = "yd"; 070 public static final String MONTHS_IGNORING_YEARS = "ym"; 071 public static final String DAYS_IGNORING_MONTHS_YEARS = "md"; 072 073 // private static final String[] CODES = { 074 // YEARS_CODE, MONTHS_CODE, DAYS_CODE, DAYS_IGNORING_YEARS, 075 // MONTHS_IGNORING_YEARS, DAYS_IGNORING_MONTHS_YEARS 076 // }; 077 // 078 079 public DateDifFunction() 080 { 081 } 082 083 public String getCanonicalName() 084 { 085 return "DATEDIF"; 086 } 087 088 public TypeValuePair evaluate(final FormulaContext context, 089 final ParameterCallback parameters) 090 throws EvaluationException 091 { 092 if (parameters.getParameterCount() != 3) 093 { 094 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE); 095 } 096 097 final TypeRegistry typeRegistry = context.getTypeRegistry(); 098 final Date date1 = typeRegistry.convertToDate 099 (parameters.getType(0), parameters.getValue(0)); 100 final Date date2 = typeRegistry.convertToDate 101 (parameters.getType(1), parameters.getValue(1)); 102 final String formatCode = typeRegistry.convertToText 103 (parameters.getType(2), parameters.getValue(2)); 104 105 if (date1 == null || date2 == null || formatCode == null || "".equals( 106 formatCode)) 107 { 108 throw new EvaluationException( 109 LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE); 110 } 111 112 final LocalizationContext localizationContext = context.getLocalizationContext(); 113 final TimeZone timeZone = localizationContext.getTimeZone(); 114 final Locale locale = localizationContext.getLocale(); 115 final GregorianCalendar calandar1 = 116 new GregorianCalendar(timeZone, locale); 117 calandar1.setTime(date1); 118 119 final GregorianCalendar calandar2 = 120 new GregorianCalendar(timeZone, locale); 121 calandar2.setTime(date2); 122 123 int res; 124 125 if (DateDifFunction.YEARS_CODE.equals(formatCode)) 126 { 127 res = calandar2.get(Calendar.YEAR) - calandar1.get(Calendar.YEAR); 128 } 129 else if (DateDifFunction.MONTHS_CODE.equals(formatCode)) 130 { 131 final int month1 = calandar1.get(Calendar.MONTH); 132 final int month2 = calandar2.get(Calendar.MONTH); 133 final int year1 = calandar1.get(Calendar.YEAR); 134 final int year2 = calandar2.get(Calendar.YEAR); 135 136 res = (year2 - year1) * 12 + 137 month2 - month1; 138 } 139 else if (DateDifFunction.DAYS_IGNORING_MONTHS_YEARS.equals(formatCode)) 140 { 141 // The number of days between Date1 and Date2, as if Date1 and 142 // Date2 were in the same month and the same year. 143 144 // Not sure what happens to leap years, so this solution may be invalid. 145 calandar1.set(Calendar.YEAR, calandar2.get(Calendar.YEAR)); 146 calandar1.set(Calendar.MONTH, calandar2.get(Calendar.MONTH)); 147 148 res = calandar2.get(Calendar.DAY_OF_MONTH) - 149 calandar1.get(Calendar.DAY_OF_MONTH); 150 } 151 else if (DateDifFunction.DAYS_CODE.equals(formatCode)) 152 { 153 final int dayOfYear1 = calandar1.get(Calendar.DAY_OF_YEAR); 154 final int dayOfYear2 = calandar2.get(Calendar.DAY_OF_YEAR); 155 final int year1 = calandar1.get(Calendar.YEAR); 156 final int year2 = calandar2.get(Calendar.YEAR); 157 158 final GregorianCalendar workingCalandar = 159 new GregorianCalendar(timeZone, locale); 160 161 res = dayOfYear2 - dayOfYear1; 162 163 // run through the inner years, without counting the border years 164 // Always run from the lower to the higher, so that we prevent infinite 165 // loops .. 166 final int targetYear = Math.max(year1, year2); 167 for (int i = Math.min(year1, year2); i < targetYear; i++) 168 { 169 workingCalandar.set(Calendar.YEAR, i); 170 res += workingCalandar.getActualMaximum(Calendar.DAY_OF_YEAR); 171 } 172 } 173 else if (DateDifFunction.MONTHS_IGNORING_YEARS.equals(formatCode)) 174 { 175 final int month1 = calandar1.get(Calendar.MONTH); 176 final int month2 = calandar2.get(Calendar.MONTH); 177 178 res = month2 - month1; 179 } 180 else if (DateDifFunction.DAYS_IGNORING_YEARS.equals(formatCode)) 181 { 182 //Isn't that a stupid case? How could we count the days while ignoring 183 //how much days there are in each months without using the year? 184 185 // The number of days between Date1 and Date2, as if Date1 and Date2 186 // were in the same year. 187 188 // Not sure what happens to leap years, so this solution may be invalid. 189 calandar1.set(Calendar.YEAR, calandar2.get(Calendar.YEAR)); 190 final int dayOne = calandar1.get(Calendar.DAY_OF_YEAR); 191 final int dayTwo = calandar2.get(Calendar.DAY_OF_YEAR); 192 res = Math.abs(dayOne - dayTwo); 193 } 194 else 195 { 196 throw new EvaluationException( 197 LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE); 198 } 199 200 if (res < 0) 201 { 202 throw new EvaluationException( 203 LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE); 204 } 205 206 return new TypeValuePair(NumberType.GENERIC_NUMBER, new Integer(res)); 207 } 208 }