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1: /** 2: * ======================================== 3: * JFreeReport : a free Java report library 4: * ======================================== 5: * 6: * Project Info: http://reporting.pentaho.org/ 7: * 8: * (C) Copyright 2000-2007, by Object Refinery Limited, Pentaho Corporation and Contributors. 9: * 10: * This library is free software; you can redistribute it and/or modify it under the terms 11: * of the GNU Lesser General Public License as published by the Free Software Foundation; 12: * either version 2.1 of the License, or (at your option) any later version. 13: * 14: * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 15: * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 16: * See the GNU Lesser General Public License for more details. 17: * 18: * You should have received a copy of the GNU Lesser General Public License along with this 19: * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, 20: * Boston, MA 02111-1307, USA. 21: * 22: * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 23: * in the United States and other countries.] 24: * 25: * ------------ 26: * $Id: IsEmptyExpression.java 3525 2007-10-16 11:43:48Z tmorgner $ 27: * ------------ 28: * (C) Copyright 2000-2005, by Object Refinery Limited. 29: * (C) Copyright 2005-2007, by Pentaho Corporation. 30: */ 31: package org.jfree.report.expressions.sys; 32: 33: import org.jfree.report.DataSourceException; 34: import org.jfree.report.expressions.AbstractExpression; 35: 36: /** 37: * Creation-Date: 27.01.2006, 20:42:19 38: * 39: * @author Thomas Morgner 40: */ 41: public class IsEmptyExpression extends AbstractExpression 42: { 43: private Object value; 44: 45: public IsEmptyExpression() 46: { 47: } 48: 49: public Object getValue() 50: { 51: return value; 52: } 53: 54: public void setValue(final Object value) 55: { 56: this.value = value; 57: } 58: 59: /** 60: * Return the current expression value. <P> The value depends (obviously) on 61: * the expression implementation. 62: * 63: * @return the value of the function. 64: */ 65: public Object computeValue() throws DataSourceException 66: { 67: if (value == null) 68: { 69: return Boolean.TRUE; 70: } 71: if (value instanceof String) 72: { 73: final String s = (String) value; 74: if (s.trim().length() == 0) 75: { 76: return Boolean.TRUE; 77: } 78: return Boolean.FALSE; 79: } 80: if (value instanceof Number) 81: { 82: final Number n = (Number) value; 83: if (n.intValue() == 0) 84: { 85: return Boolean.TRUE; 86: } 87: return Boolean.FALSE; 88: } 89: return Boolean.FALSE; 90: } 91: }