01: /*
02: * $Id: ArithmeticFunction.java,v 1.9 2005/12/20 18:32:28 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 java.math.BigDecimal;
44:
45: import org.axiondb.AxionException;
46: import org.axiondb.DataType;
47: import org.axiondb.RowDecorator;
48: import org.axiondb.Selectable;
49: import org.axiondb.types.BigDecimalType;
50:
51: /**
52: * @version $Revision: 1.9 $ $Date: 2005/12/20 18:32:28 $
53: * @author Rodney Waldhoff
54: * @author Jonathan Giron
55: */
56: public abstract class ArithmeticFunction extends BaseFunction implements
57: ScalarFunction {
58: public ArithmeticFunction(String name) {
59: super (name);
60: }
61:
62: public final DataType getDataType() {
63: return (_datatype == null) ? new BigDecimalType() : _datatype;
64: }
65:
66: public final Object evaluate(RowDecorator row)
67: throws AxionException {
68: BigDecimal result = null;
69: for (int i = 0, I = getArgumentCount(); i < I; i++) {
70: Selectable sel = getArgument(i);
71: Object val = sel.evaluate(row);
72: if (null == val) {
73: return null;
74: }
75:
76: BigDecimal bdval = sel.getDataType().toBigDecimal(val);
77: if (null == result) {
78: result = bdval;
79: } else {
80: result = operate(result, bdval);
81: }
82: }
83: return result;
84: }
85:
86: public final boolean isValid() {
87: return (getArgumentCount() != 0);
88: }
89:
90: protected abstract BigDecimal operate(BigDecimal left,
91: BigDecimal right) throws AxionException;
92:
93: protected void setDataType(DataType newType) {
94: _datatype = newType;
95: }
96:
97: private DataType _datatype = null;
98: }
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