01: /*
02: * $Id: ABSFunction.java,v 1.6 2005/04/24 21:33:11 ahimanikya Exp $
03: * =======================================================================
04: * Copyright (c) 2002-2005 Axion Development Team. All rights reserved.
05: *
06: * Redistribution and use in source and binary forms, with or without
07: * modification, are permitted provided that the following conditions
08: * are met:
09: *
10: * 1. Redistributions of source code must retain the above
11: * copyright notice, this list of conditions and the following
12: * disclaimer.
13: *
14: * 2. Redistributions in binary form must reproduce the above copyright
15: * notice, this list of conditions and the following disclaimer in
16: * the documentation and/or other materials provided with the
17: * distribution.
18: *
19: * 3. The names "Tigris", "Axion", nor the names of its contributors may
20: * not be used to endorse or promote products derived from this
21: * software without specific prior written permission.
22: *
23: * 4. Products derived from this software may not be called "Axion", nor
24: * may "Tigris" or "Axion" appear in their names without specific prior
25: * written permission.
26: *
27: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
30: * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31: * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38: * =======================================================================
39: */
40:
41: package org.axiondb.functions;
42:
43: import org.axiondb.AxionException;
44: import org.axiondb.DataType;
45: import org.axiondb.FunctionFactory;
46: import org.axiondb.RowDecorator;
47: import org.axiondb.Selectable;
48: import org.axiondb.types.BigDecimalType;
49: import java.math.BigDecimal;
50:
51: /**
52: * @version $Revision: 1.6 $ $Date: 2005/04/24 21:33:11 $
53: * @author Ahimanikya Satapathy
54: * @author Sanjeeth Duvuru
55: */
56: public class ABSFunction extends BaseFunction implements
57: ScalarFunction, FunctionFactory {
58:
59: public ABSFunction() {
60: super ("ABS");
61: }
62:
63: public ConcreteFunction makeNewInstance() {
64: return new ABSFunction();
65: }
66:
67: public DataType getDataType() {
68: return (_datatype == null) ? RETURN_TYPE : _datatype;
69: }
70:
71: public Object evaluate(RowDecorator row) throws AxionException {
72: Selectable sel = getArgument(0);
73: Object val = sel.evaluate(row);
74:
75: _datatype = sel.getDataType();
76: BigDecimal bdVal = _datatype.toBigDecimal(val);
77: if (null == bdVal) {
78: return null;
79: }
80:
81: return _datatype.convert(bdVal.abs());
82: }
83:
84: public boolean isValid() {
85: return getArgumentCount() == 1;
86: }
87:
88: private static final DataType RETURN_TYPE = new BigDecimalType();
89: private DataType _datatype = null;
90: }
|