//===================START_PROLOG======================================
//
// 5630-A23, 5630-A22,
// (C) COPYRIGHT International Business Machines Corp. 2002
// All Rights Reserved // Licensed Materials - Property of IBM
//
// IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
// ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL, INDIRECT OR
// CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
// USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE
// OR PERFORMANCE OF THIS SOFTWARE.
//
//===================END_PROLOG========================================
package WebSphereSamples.ConnPool;
import java.util.*;
import java.sql.*;
import javax.sql.*;
import javax.ejb.*;
import javax.naming.*;
/*************************************************************************************
* This bean is designed to demonstrate Database Connections in a
* Container Managed Transaction Session Bean. Its transaction attribute *
* should be set to TX_REQUIRED or TX_REQUIRES_NEW. *
**************************************************************************************
*/
public class ShowEmployeesCMTBean implements SessionBean {
private javax.ejb.SessionContext mySessionCtx = null;
final static long serialVersionUID = 3206093459760846163L;
private javax.sql.DataSource ds;
//************************************************************************************
//* ejbActivate calls the getDS method, which does the JNDI lookup for the DataSource.
//* Because the DataSource lookup is in a separate method, we can also invoke it from
//* the getEmployees method in the case where the DataSource field is null.
//************************************************************************************
public void ejbActivate() throws java.rmi.EJBException {
getDS();
}
/**
* ejbCreate method * @exception javax.ejb.CreateException * @exception java.rmi.EJBException */
public void ejbCreate() throws javax.ejb.CreateException, java.rmi.EJBException {}
/**
* ejbPassivate method
* @exception java.rmi.EJBException */
public void ejbPassivate() throws java.rmi.EJBException {}
/**
* ejbRemove method
* @exception java.rmi.EJBException
*/
public void ejbRemove() throws java.rmi.EJBException {}
//************************************************************************************
//* The getEmployees method runs the database query to retrieve the employees.
//* The getDS method is only called if the DataSource variable is null.
//* Because this session bean uses Container Managed Transactions, it cannot retry the
//* transaction on a StaleConnectionException. However, it can throw an exception to
//* its client indicating that the operation is retriable. *
//************************************************************************************
public Vector getEmployees() throws com.ibm.ejs.cm.pool.ConnectionWaitTimeoutException, SQLException, RetryableConnectionException {
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
Vector employeeList = new Vector();
if (ds == null) getDS();
try {
// Get a Connection object conn using the DataSource factory.
conn = ds.getConnection();
// Run DB query using standard JDBC coding.
stmt = conn.createStatement();
String query = "Select FirstNme, MidInit, LastName " +
"from Employee ORDER BY LastName";
rs = stmt.executeQuery(query);
while (rs.next()) {
employeeList.addElement(rs.getString(3) + ", " + rs.getString(1) + " " + rs.getString(2));
}
}
catch (com.ibm.websphere.ce.cm.StaleConnectionException se) {
// This exception indicates that the connection to the database is no longer valid.
// Rollback the transaction, and throw an exception to the client indicating they // can retry the transaction if desired.
System.out.println("Stale Connection Exception during get connection or process SQL: " + se.getMessage());
System.out.println("Rolling back transaction and throwing RetryableConnectionException");
mySessionCtx.setRollbackOnly();
throw new RetryableConnectionException(se.toString());
}
catch (com.ibm.ejs.cm.pool.ConnectionWaitTimeoutException cw) {
// This exception is thrown if a connection can not be obtained from the // pool within a configurable amount of time. Frequent occurrences of // this exception indicate an incorrectly tuned connection pool
System.out.println("Connection Wait Timeout Exception during get connection or process SQL: " + cw.getMessage());
throw cw;
}
catch (SQLException sq) {
//Throwing a remote exception will automatically roll back the container managed //transaction
System.out.println("SQL Exception during get connection or process SQL: " +
sq.getMessage());
throw sq;
}
finally {
// Always close the connection in a finally statement to ensure proper
// closure in all cases. Closing the connection does not close and
// actual connection, but releases it back to the pool for reuse.
if (rs != null) {
try {
rs.close();
}
catch (Exception e) {
System.out.println("Close Resultset Exception: " + e.getMessage());
}
}
if (stmt != null) {
try {
stmt.close();
}
catch (Exception e) {
System.out.println("Close Statement Exception: " + e.getMessage());
}
}
if (conn != null) {
try {
conn.close();
}
catch (Exception e) {
System.out.println("Close connection exception: " + e.getMessage());
}
}
}
return employeeList;
}
/**
* getSessionContext method * @return javax.ejb.SessionContext */
public javax.ejb.SessionContext getSessionContext() {
return mySessionCtx;
}
//************************************************************************************
//* The getDS method performs the JNDI lookup for the DataSource. *
//* This method is called from ejbActivate, and from getEmployees if the DataSource
//* object is null. *
//************************************************************************************
private void getDS() {
try {
Hashtable parms = new Hashtable();
parms.put(Context.INITIAL_CONTEXT_FACTORY,
"com.ibm.websphere.naming.WsnInitialContextFactory");
InitialContext ctx = new InitialContext(parms);
// Perform a naming service lookup to get the DataSource object.
ds = (DataSource)ctx.lookup("java:comp/env/jdbc/SampleDB");
}
catch (Exception e) {
System.out.println("Naming service exception: " + e.getMessage());
e.printStackTrace();
}
}
/**
* setSessionContext method
* @param ctx javax.ejb.SessionContext * @exception java.rmi.EJBException */
public void setSessionContext(javax.ejb.SessionContext ctx) throws java.rmi.EJBException {
mySessionCtx = ctx;
}
}
//===================START_PROLOG======================================
//
// 5630-A23, 5630-A22,
// (C) COPYRIGHT International Business Machines Corp. 2002
// All Rights Reserved // Licensed Materials - Property of IBM
//
// IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
// ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL, INDIRECT OR
// CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
// USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE
// OR PERFORMANCE OF THIS SOFTWARE.
//
//===================END_PROLOG========================================
package WebSphereSamples.ConnPool;
/**
* This is a Home interface for the Session Bean */
public interface ShowEmployeesCMTHome extends javax.ejb.EJBHome {
/**
* create method for a session bean * @return WebSphereSamples.ConnPool.ShowEmployeesCMT
* @exception javax.ejb.CreateException * @exception java.rmi.RemoteException */
WebSphereSamples.ConnPool.ShowEmployeesCMT create() throws javax.ejb.CreateException, java.rmi.RemoteException;
}
//===================START_PROLOG======================================
//
// 5630-A23, 5630-A22,
// (C) COPYRIGHT International Business Machines Corp. 2002
// All Rights Reserved // Licensed Materials - Property of IBM
//
// IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
// ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL, INDIRECT OR
// CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
// USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE
// OR PERFORMANCE OF THIS SOFTWARE.
//
//===================END_PROLOG========================================
package WebSphereSamples.ConnPool;
/**
* This is an Enterprise Java Bean Remote Interface */
public interface ShowEmployeesCMT extends javax.ejb.EJBObject {
/**
*
* @return java.util.Vector */
java.util.Vector getEmployees() throws java.sql.SQLException, java.rmi.RemoteException, com.ibm.ejs.cm.pool.ConnectionWaitTimeoutException, WebSphereSamples.ConnPool.RetryableConnectionException;
}
//===================START_PROLOG======================================
//
// 5630-A23, 5630-A22,
// (C) COPYRIGHT International Business Machines Corp. 2002
// All Rights Reserved // Licensed Materials - Property of IBM
//
// IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
// ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL, INDIRECT OR
// CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
// USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE
// OR PERFORMANCE OF THIS SOFTWARE.
//
//===================END_PROLOG========================================
package WebSphereSamples.ConnPool;
/**
* Exception indicating that the operation can be retried * Creation date: (4/2/2001 10:48:08 AM)
* @author: Administrator */
public class RetryableConnectionException extends Exception {
/**
* RetryableConnectionException constructor.
*/
public RetryableConnectionException() {
super();
}
/**
* RetryableConnectionException constructor.
* @param s java.lang.String */
public RetryableConnectionException(String s) {
super(s);
}
}
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