我有 oracle 数据库 11.2，我正在尝试让 oracle 更改通知正常工作。但它似乎没有通知我，我正在使用 ojdbc6.jar。表正在注册到通知中；通过运行验证
select * from USER_CHANGE_NOTIFICATION_REGS
当我从外部客户端对表执行更新时，我的侦听器没有被调用。但是当我关闭/启动数据库时，它会通知。
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 DBChangeNotification
{
static final String USERNAME= "scott";
static final String PASSWORD= "tiger";
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 .:ojdbc5.jar DBChangeNotification \"jdbc:oracle:thin: @(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=yourhost.yourdomain.com)(PORT=1521)) CONNECT_DATA=(SERVICE_NAME=yourservicename)))\"");
System.exit(1);
}
URL = argv[0];
DBChangeNotification demo = new DBChangeNotification();
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();
// if connected through the VPN, you need to provide the TCP address of the client.
// For example:
// prop.setProperty(OracleConnection.NTF_LOCAL_HOST,"14.14.13.12");
// Ask the server to send the ROWIDs as part of the DCN events (small performance
// cost):
prop.setProperty(OracleConnection.DCN_NOTIFY_ROWIDS,"true");
//
//Set the DCN_QUERY_CHANGE_NOTIFICATION option for query registration with finer granularity.
prop.setProperty(OracleConnection.DCN_QUERY_CHANGE_NOTIFICATION,"true");
// The following operation does a roundtrip to the database to create a new
// registration for DCN. It sends the client address (ip address and port) that
// the server will use to connect to the client and send the notification
// when necessary. Note that for now the registration is empty (we haven't registered
// any table). This also opens a new thread in the drivers. This thread will be
// dedicated to DCN (accept connection to the server and dispatch the events to
// the listeners).
DatabaseChangeRegistration dcr = conn.registerDatabaseChangeNotification(prop);
try
{
// add the listenerr:
DCNDemoListener list = new DCNDemoListener(this);
dcr.addListener(list);
// second step: add objects in the registration:
Statement stmt = conn.createStatement();
// associate the statement with the registration:
((OracleStatement)stmt).setDatabaseChangeRegistration(dcr);
ResultSet rs = stmt.executeQuery("select rowid from dept where 1 = 2");
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 )
{
// wait until we get the event
try{ this.wait();} catch( InterruptedException ie ) {}
}
// At the end: close the registration (comment out these 3 lines in order
// to leave the registration open).
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",DBChangeNotification.USERNAME);
prop.setProperty("password",DBChangeNotification.PASSWORD);
return (OracleConnection)dr.connect(DBChangeNotification.URL,prop);
}
}
/**
* DCN listener: it prints out the event details in stdout.
*/
class DCNDemoListener implements DatabaseChangeListener
{
DBChangeNotification demo;
DCNDemoListener(DBChangeNotification 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();}
}
}