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: DayFunction.java 2822 2007-05-20 21:47:52Z mimil $ 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; 035 036 import org.jfree.formula.EvaluationException; 037 import org.jfree.formula.FormulaContext; 038 import org.jfree.formula.LibFormulaErrorValue; 039 import org.jfree.formula.function.Function; 040 import org.jfree.formula.function.ParameterCallback; 041 import org.jfree.formula.lvalues.TypeValuePair; 042 import org.jfree.formula.typing.TypeRegistry; 043 import org.jfree.formula.typing.coretypes.NumberType; 044 import org.jfree.formula.util.DateUtil; 045 046 /** 047 * This function extracts the day from a date. 048 * 049 * @author Cedric Pronzato 050 */ 051 public class DayFunction implements Function 052 { 053 public DayFunction() 054 { 055 } 056 057 public String getCanonicalName() 058 { 059 return "DAY"; 060 } 061 062 public TypeValuePair evaluate(final FormulaContext context, 063 final ParameterCallback parameters) throws EvaluationException 064 { 065 if (parameters.getParameterCount() != 1) 066 { 067 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE); 068 } 069 070 final TypeRegistry typeRegistry = context.getTypeRegistry(); 071 072 final Date d = typeRegistry.convertToDate(parameters.getType(0), parameters 073 .getValue(0)); 074 075 if (d == null) 076 { 077 throw new EvaluationException( 078 LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE); 079 } 080 081 final Calendar gc = DateUtil.createCalendar(d, context 082 .getLocalizationContext()); 083 084 final int dayOfMonth = gc 085 .get(Calendar.DAY_OF_MONTH); 086 return new TypeValuePair(NumberType.GENERIC_NUMBER, new Integer(dayOfMonth)); 087 } 088 }