import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
import oracle.jdbc.OracleConnection;
import oracle.jdbc.OracleDriver;
import oracle.jdbc.OracleStatement;
import oracle.jdbc.dcn.DatabaseChangeEvent;
import oracle.jdbc.dcn.DatabaseChangeListener;
import oracle.jdbc.dcn.DatabaseChangeRegistration;
public class QCN19demo
{
static final String USERNAME= "o";
static final String PASSWORD= "password"
static String URL;
public static void main(String[] argv)
{
if(argv.length < 1)
{
System.out.println("Error: You need to provide the URL in the first argument.");
System.out.println(" For example: > java -classpath .:ojdbc6.jar DBChangeNotification \"jdbc:oracle:thin: @(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=yourhost.yourdomain.com)(PORT=5221))(CONNECT_DATA= (SERVICE_NAME=orcl)))\"");
System.exit(1);A
}
URL = argv[0];
QCN19demo demo = new QCN19demo();
try
{
demo.run();
}
catch(SQLException mainSQLException )
{
mainSQLException.printStackTrace();
}
}
void run() throws SQLException
{
OracleConnection conn = connect();
// first step: create a registration on the server:
Properties prop = new Properties();
prop.setProperty(OracleConnection.DCN_NOTIFY_ROWIDS,"true");
prop.setProperty(OracleConnection.DCN_BEST_EFFORT,"true");
prop.setProperty(OracleConnection.DCN_CLIENT_INIT_CONNECTION, "true");
prop.setProperty(OracleConnection.DCN_QUERY_CHANGE_NOTIFICATION,"true");
DatabaseChangeRegistration dcr = conn.registerDatabaseChangeNotification(prop);
try
{
// add the listenerr:
DCNDemoListener list = new DCNDemoListener(this);
dcr.addListener(list);
Statement stmt = conn.createStatement();
((OracleStatement)stmt).setDatabaseChangeRegistration(dcr);
ResultSet rs = stmt.executeQuery("select Action, Subject, Description, category, attendees, location, StartDate, EndDate, Allday, ResponseReq, Reminder, resources, BusyStatus, serveddate, rowid from Calendarrequests where serveddate is null order by 1");
while (rs.next())
{}
String[] tableNames = dcr.getTables();
for(int i=0;i<tableNames.length;i++)
System.out.println(tableNames[i]+" is part of the registration.");
rs.close();
stmt.close();
}
catch(SQLException ex)
{
// if an exception occurs, we need to close the registration in order
// to interrupt the thread otherwise it will be hanging around.
if(conn != null)
conn.unregisterDatabaseChangeNotification(dcr);
throw ex;
}
finally
{
try
{
// Note that we close the connection!
conn.close();
}
catch(Exception innerex){ innerex.printStackTrace(); }
}
synchronized( this )
{
// The following code modifies the dept table and commits:
try
{
while(true)
{
// wait until we get the event
try{ this.wait();} catch( InterruptedException ie ) {}
}
}
catch(RuntimeException ex)
{
ex.printStackTrace();
OracleConnection conn3 = connect();
conn3.unregisterDatabaseChangeNotification(dcr);
conn3.close();
}
catch(Exception ex) { ex.printStackTrace(); }
finally
{
OracleConnection conn3 = connect();
conn3.unregisterDatabaseChangeNotification(dcr);
conn3.close();
}
}
}
/**
* Creates a connection the database.
*/
OracleConnection connect() throws SQLException
{
OracleDriver dr = new OracleDriver();
Properties prop = new Properties();
prop.setProperty("user",QCN19demo.USERNAME);
prop.setProperty("password",QCN19demo.PASSWORD);
return (OracleConnection)dr.connect(QCN19demo.URL,prop);
}
}
/**
* DCN listener: it prints out the event details in stdout.
*/
class DCNDemoListener implements DatabaseChangeListener
{
QCN19demo demo;
DCNDemoListener(QCN19demo dem)
{
demo = dem;
}
public void onDatabaseChangeNotification(DatabaseChangeEvent e)
{
Thread t = Thread.currentThread();
System.out.println("DCNDemoListener: got an event ("+this+" running on thread "+t+")");
System.out.println(e.toString());
synchronized( demo ){ demo.notify();}
}
}