001: /*
002: * $Id: CharToDateFunction.java,v 1.7 2005/03/05 01:35:35 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.StringType;
048: import org.axiondb.types.TimestampType;
049: import org.axiondb.util.DateTimeUtils;
050:
051: /**
052: * Syntax: CharToDate( date-string, 'format-literal' )
053: *
054: * @version $Revision: 1.7 $ $Date: 2005/03/05 01:35:35 $
055: * @author Jonathan Giron
056: */
057: public class CharToDateFunction extends BaseFunction implements
058: ScalarFunction, FunctionFactory {
059:
060: /** Creates a new instance of Class */
061: public CharToDateFunction() {
062: super ("CHARTODATE");
063: }
064:
065: public ConcreteFunction makeNewInstance() {
066: return new CharToDateFunction();
067: }
068:
069: /** {@link DataType} */
070: public DataType getDataType() {
071: return RETURN_TYPE;
072: }
073:
074: /**
075: * Gets String value representing the timestamp/date value in the given format.
076: *
077: * @param row
078: * @return String representation of the timestamp/date value
079: */
080: public Object evaluate(RowDecorator row) throws AxionException {
081: String dateStr = null;
082: String formatStr = null;
083:
084: // Get 'format-literal'
085: Object arg2 = getArgument(1).evaluate(row);
086: if (null == arg2) {
087: throw new AxionException(
088: "CharToDate cannot accept a null format string.");
089: } else {
090: formatStr = (String) STRING_TYPE.convert(arg2);
091: }
092:
093: // Get 'date-string'
094: Object arg1 = getArgument(0).evaluate(row);
095: if (null == arg1) {
096: return null;
097: } else {
098: dateStr = (String) STRING_TYPE.convert(arg1);
099: }
100:
101: return DateTimeUtils.convertToTimestamp(dateStr, formatStr);
102: }
103:
104: public boolean isValid() {
105: return getArgumentCount() >= 2;
106: }
107:
108: private static final DataType RETURN_TYPE = new TimestampType();
109: private static final DataType STRING_TYPE = new StringType();
110: }
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