001: /*
002: * $Id: InStringFunction.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.IntegerType;
048: import org.axiondb.types.StringType;
049: import org.axiondb.util.ValuePool;
050:
051: /**
052: * INSTR(str,substr): Returns the position of the first occurrence of substring substr in
053: * string str.
054: *
055: * @version $Revision: 1.8 $ $Date: 2005/12/20 18:32:28 $
056: * @author Sanjeeth Duvuru
057: * @author Ahimanikya Satapathy
058: */
059: public class InStringFunction extends BaseFunction implements
060: ScalarFunction, FunctionFactory {
061:
062: public InStringFunction() {
063: super ("INSTRING");
064: }
065:
066: public ConcreteFunction makeNewInstance() {
067: return new InStringFunction();
068: }
069:
070: /** {@link StringType} */
071: public DataType getDataType() {
072: return RETURN_TYPE;
073: }
074:
075: public Object evaluate(RowDecorator row) throws AxionException {
076: int pos = -1;
077: String str = (String) getArgument(0).evaluate(row);
078: String substr = (String) getArgument(1).evaluate(row);
079:
080: if (str == null || substr == null) {
081: return ValuePool.getInt(pos);
082: }
083:
084: if (getArgumentCount() == 3) {
085: Object val3 = getArgument(2).evaluate(row);
086: if (val3 != null) {
087: Integer startPos = (Integer) (ARG_TYPE.convert(val3));
088: if (startPos.intValue() >= 0) {
089: pos = str.indexOf(substr, startPos.intValue());
090: } else {
091: int fromIdx = str.length()
092: - Math.abs(startPos.intValue());
093: pos = str.lastIndexOf(substr, fromIdx);
094: }
095: } else {
096: throw new AxionException("Value " + val3
097: + " cannot be converted to a " + ARG_TYPE);
098: }
099: } else {
100: pos = str.indexOf(substr);
101: }
102: return ValuePool.getInt(pos);
103: }
104:
105: public boolean isValid() {
106: return (getArgumentCount() >= 2 && getArgumentCount() < 4);
107: }
108:
109: private static final DataType RETURN_TYPE = new StringType();
110: private static final DataType ARG_TYPE = new IntegerType();
111: }
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