001: /*
002: * $Id: DifferenceFunction.java,v 1.8 2005/12/20 18:32:28 ahimanikya Exp $
003: * =======================================================================
004: * Copyright (c) 2002-2005 Axion Development Team. All rights reserved.
005: *
006: * Redistribution and use in source and binary forms, with or without
007: * modification, are permitted provided that the following conditions
008: * are met:
009: *
010: * 1. Redistributions of source code must retain the above
011: * copyright notice, this list of conditions and the following
012: * disclaimer.
013: *
014: * 2. Redistributions in binary form must reproduce the above copyright
015: * notice, this list of conditions and the following disclaimer in
016: * the documentation and/or other materials provided with the
017: * distribution.
018: *
019: * 3. The names "Tigris", "Axion", nor the names of its contributors may
020: * not be used to endorse or promote products derived from this
021: * software without specific prior written permission.
022: *
023: * 4. Products derived from this software may not be called "Axion", nor
024: * may "Tigris" or "Axion" appear in their names without specific prior
025: * written permission.
026: *
027: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
028: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
029: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
030: * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
031: * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
032: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
033: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
034: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
035: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
036: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
037: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
038: * =======================================================================
039: */
040:
041: package org.axiondb.functions;
042:
043: import org.axiondb.AxionException;
044: import org.axiondb.DataType;
045: import org.axiondb.FunctionFactory;
046: import org.axiondb.RowDecorator;
047: import org.axiondb.types.BooleanType;
048: import org.axiondb.types.StringType;
049: import org.axiondb.util.ValuePool;
050:
051: /**
052: * @version $Revision: 1.8 $ $Date: 2005/12/20 18:32:28 $
053: * @author Sudhendra Seshachala
054: * @author Ahimanikya Satapathy
055: */
056: public class DifferenceFunction extends SoundexFunction implements
057: ScalarFunction, FunctionFactory {
058:
059: /** Creates a new instance of Class */
060: public DifferenceFunction() {
061: super ("DIFFERENCE");
062: }
063:
064: public ConcreteFunction makeNewInstance() {
065: return new DifferenceFunction();
066: }
067:
068: /** {@link StringType} */
069: public DataType getDataType() {
070: return RETURN_TYPE;
071: }
072:
073: public Object evaluate(RowDecorator row) throws AxionException {
074: Object val = getArgument(0).evaluate(row);
075: Object val1 = getArgument(1).evaluate(row);
076:
077: String intVal = (String) (ARG_TYPE.convert(val));
078: String intVal1 = (String) (ARG_TYPE.convert(val1));
079: if (null != intVal && intVal1 != null) {
080: intVal = soundex(intVal);
081: intVal1 = soundex(intVal1);
082:
083: int e = 4;
084: for (int i = 0; i < 4; i++) {
085: if (intVal.charAt(i) != intVal1.charAt(i)) {
086: e--;
087: }
088: }
089: return ValuePool.getInt(e);
090: } else {
091: return null;
092: }
093: }
094:
095: public boolean isValid() {
096: return (getArgumentCount() == 2);
097: }
098:
099: private static final DataType ARG_TYPE = new StringType();
100: private static final DataType RETURN_TYPE = new BooleanType();
101: }
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