001: /*
002: * ====================================================================
003: * JAFFA - Java Application Framework For All
004: *
005: * Copyright (C) 2002 JAFFA Development Group
006: *
007: * This library is free software; you can redistribute it and/or
008: * modify it under the terms of the GNU Lesser General Public
009: * License as published by the Free Software Foundation; either
010: * version 2.1 of the License, or (at your option) any later version.
011: *
012: * This library is distributed in the hope that it will be useful,
013: * but WITHOUT ANY WARRANTY; without even the implied warranty of
014: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015: * Lesser General Public License for more details.
016: *
017: * You should have received a copy of the GNU Lesser General Public
018: * License along with this library; if not, write to the Free Software
019: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
020: *
021: * Redistribution and use of this software and associated documentation ("Software"),
022: * with or without modification, are permitted provided that the following conditions are met:
023: * 1. Redistributions of source code must retain copyright statements and notices.
024: * Redistributions must also contain a copy of this document.
025: * 2. Redistributions in binary form must reproduce the above copyright notice,
026: * this list of conditions and the following disclaimer in the documentation
027: * and/or other materials provided with the distribution.
028: * 3. The name "JAFFA" must not be used to endorse or promote products derived from
029: * this Software without prior written permission. For written permission,
030: * please contact mail to: jaffagroup@yahoo.com.
031: * 4. Products derived from this Software may not be called "JAFFA" nor may "JAFFA"
032: * appear in their names without prior written permission.
033: * 5. Due credit should be given to the JAFFA Project (http://jaffa.sourceforge.net).
034: *
035: * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
036: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
037: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
038: * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
039: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
040: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
041: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
042: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
043: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
044: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
045: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
046: * SUCH DAMAGE.
047: * ====================================================================
048: */
049:
050: package org.jaffa.components.voucher;
051:
052: import java.util.Collection;
053: import java.util.Iterator;
054: import org.jaffa.persistence.UOW;
055: import org.jaffa.exceptions.ApplicationExceptions;
056: import org.jaffa.exceptions.FrameworkException;
057: import org.jaffa.persistence.Criteria;
058: import org.jaffa.util.BeanHelper;
059: import org.jaffa.util.StringHelper;
060:
061: /** This is a very simple implementation of the IVoucherGenerator interface.
062: * It has 2 additional properties which need to be set before invoking the generate method
063: * 1- DomainClassName: A fully qualified classname for the domain class
064: * 2- FieldName: A fieldname
065: *
066: * This implementation will merely perform the following query:
067: * 'SELECT [fieldname] FROM [domainclassname] ORDER BY [fieldname] DESC'
068: *
069: * It will then generate the voucher by
070: * 1- Incrementing the number portion from the value retrieved
071: * 2- Appending the number to the prefix with appropriate padding
072: *
073: * NOTE:
074: * This implementation suffers from a very serious drawback - 2 THREADS CAN OBTAIN THE SAME VOUCHER
075: * This class is intended for demo purposes only.
076: * It SHOULD NOT be used in a production environment.
077: *
078: * @author GautamJ
079: */
080: public class SimpleVoucherGenerator extends AbstractVoucherGenerator {
081:
082: private String m_domainClassName;
083: private String m_fieldName;
084:
085: /** Getter for the property domainClassName.
086: * @return Value of property domainClassName.
087: */
088: public String getDomainClassName() {
089: return m_domainClassName;
090: }
091:
092: /** Setter for property domainClassName.
093: * @param domainClassName New value of property domainClassName.
094: */
095: public void setDomainClassName(String domainClassName) {
096: m_domainClassName = domainClassName;
097: }
098:
099: /** Getter for the property fieldName.
100: * @return Value of property fieldName.
101: */
102: public String getFieldName() {
103: return m_fieldName;
104: }
105:
106: /** Setter for property fieldName.
107: * @param fieldName New value of property fieldName.
108: */
109: public void setFieldName(String fieldName) {
110: m_fieldName = fieldName;
111: }
112:
113: /** The client will invoke this method to generate a voucher.
114: * @throws FrameworkException if any framework error occurs.
115: * @throws ApplicationExceptions if any application error occurs.
116: * @return a unique voucher.
117: */
118: public String generate() throws FrameworkException,
119: ApplicationExceptions {
120: String voucher = null;
121: String numericPortion = null;
122: UOW uow = getUow();
123: boolean localUow = (uow == null);
124: try {
125: if (localUow)
126: uow = new UOW();
127:
128: Criteria c = new Criteria();
129: c.setTable(getDomainClassName());
130: c.addOrderBy(StringHelper.getUpper1(getFieldName()),
131: Criteria.ORDER_BY_DESC);
132: Collection col = uow.query(c);
133: Iterator itr = col.iterator();
134: if (itr.hasNext()) {
135: Object domainObject = itr.next();
136: try {
137: Object fieldValue = BeanHelper.getField(
138: domainObject, getFieldName());
139: if (fieldValue != null)
140: numericPortion = StringHelper
141: .pad(
142: Integer
143: .parseInt(fieldValue
144: .toString()
145: .substring(
146: getPrefix()
147: .length())) + 1,
148: Integer.parseInt(getLength()));
149: } catch (Exception e) {
150: throw new VoucherGeneratorException(null, e);
151: }
152: }
153: if (numericPortion == null)
154: numericPortion = StringHelper.pad(0, Integer
155: .parseInt(getLength()));
156: voucher = getPrefix() + numericPortion;
157: col.clear();
158: return voucher;
159: } finally {
160: if (localUow && uow != null)
161: uow.rollback();
162: }
163: }
164:
165: }
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