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1
51
52 package org.objectweb.jass.examples.travelagency.ejbs;
53
54 import org.objectweb.jass.examples.travelagency.exceptions.DBException;
55 import org
56 .objectweb
57 .jass
58 .examples
59 .travelagency
60 .exceptions
61 .NotEnoughSeatsException;
62 import org
63 .objectweb
64 .jass
65 .examples
66 .travelagency
67 .ejbs
68 .compensations
69 .ReserveSeatsCompensation;
70
71 import javax.ejb.EJBException  ;
72 import javax.ejb.SessionBean ;
73 import javax.ejb.SessionContext ;
74 import javax.naming.Context ;
75 import javax.naming.InitialContext ;
76 import javax.naming.NamingException ;
77 import javax.sql.DataSource ;
78 import javax.activity.opennested.UserOpenNested;
79 import java.sql.Connection ;
80 import java.sql.Statement ;
81 import java.sql.ResultSet ;
82 import java.sql.SQLException ;
83
84
92 public class AirlineBean implements SessionBean {
93 private UserOpenNested uon = null;
94 private DataSource ds = null;
95
96 public void ejbCreate() throws javax.ejb.CreateException {
97 uon = getUserOpenNested();
98 ds = getDataSource();
99 System.out.println("Airline stateless EJB created!!!");
100 }
101
102 public void ejbActivate() throws EJBException {
103 }
104
105 public void ejbPassivate() throws EJBException {
106 }
107
108 public void ejbRemove() throws EJBException {
109 uon = null;
110 ds = null;
111 System.out.println("Airline stateless EJB removed!!!");
112 }
113
114 public void setSessionContext(SessionContext sessionContext)
115 throws EJBException {
116 }
117
118
122 public int getFreeSeats() throws DBException {
123 Connection c = null;
124 Statement stmt = null;
125 ResultSet rs = null;
126 int seats = -1;
127
128 try {
129 c = ds.getConnection();
130 stmt = c.createStatement();
131 rs = stmt.executeQuery("SELECT seats FROM flights");
132 if (rs.next()) {
133 seats = rs.getInt(1);
134 }
135 rs.close();
136 stmt.close();
137 c.close();
138 } catch (SQLException e) {
139 throw new DBException();
140 }
141 return seats;
142 }
143
144
151 public int reserveSeats(int nSeats)
152 throws NotEnoughSeatsException, DBException {
153 Connection c = null;
154 Statement stmt = null;
155 ResultSet rs = null;
156 int result = -1;
157
158 try {
159 uon.activityBegin(0);
160 c = ds.getConnection();
161 stmt = c.createStatement();
162 rs = stmt.executeQuery("SELECT seats FROM flights");
163 rs.next();
164 int freeSeats = rs.getInt(1);
165 if ((freeSeats - nSeats) < 0) {
166 rs.close();
167 stmt.close();
168 c.close();
169 uon.activityRollback();
170 throw new NotEnoughSeatsException();
171 } else {
172 stmt.executeUpdate(
173 "UPDATE flights SET seats = " + (freeSeats - nSeats));
174 ReserveSeatsCompensation compensation =
175 new ReserveSeatsCompensation(this, nSeats);
176 uon.activityCommit(compensation);
177 }
178 rs.close();
179 stmt.close();
180 c.close();
181 result = nSeats;
182 } catch (SQLException e) {
183 try {
184 uon.activityRollback();
185 } catch (Exception e1) {
186 e1.printStackTrace();
187 }
188 throw new DBException();
189 } catch (NotEnoughSeatsException e) {
190 throw e;
191 } catch (Exception e) {
192 e.printStackTrace();
193 }
194 return result;
195 }
196
197
202 public int unreserveSeats(int nSeats) throws DBException {
203 Connection c = null;
204 Statement stmt = null;
205 ResultSet rs = null;
206 int result = -1;
207
208 try {
209 uon.activityBegin(0);
210 c = ds.getConnection();
211 stmt = c.createStatement();
212 rs = stmt.executeQuery("SELECT seats FROM flights");
213 rs.next();
214 int freeSeats = rs.getInt(1);
215 stmt.executeUpdate(
216 "UPDATE flights SET seats = " + (freeSeats + nSeats));
217 uon.activityCommit(null);
218 rs.close();
219 stmt.close();
220 c.close();
221 result = nSeats;
222 } catch (SQLException e) {
223 try {
224 uon.activityRollback();
225 } catch (Exception e1) {
226 e1.printStackTrace();
227 }
228 throw new DBException();
229 } catch (Exception e) {
230 e.printStackTrace();
231 }
232 return result;
233 }
234
235
238 private UserOpenNested getUserOpenNested() {
239 UserOpenNested uon = null;
240 Context ctx = null;
241
242 try {
243 ctx = new InitialContext ();
244 uon = (UserOpenNested) ctx.lookup("UserOpenNested");
245 } catch (Exception e) {
246 e.printStackTrace();
247 }
248 return uon;
249 }
250
251
254 private DataSource getDataSource() {
255 Context ctx = null;
256 DataSource ds = null;
257 try {
258 ctx = new InitialContext ();
259 ds = (DataSource ) ctx.lookup("java:/AdaptAirlineDS");
260 } catch (NamingException e) {
261 e.printStackTrace();
262 }
263 return ds;
264 }
265 }
266 |
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