My experiement indicates that IConnectionProfile.createConnection(f,u,p) ignores the u, p and always grabs them from the base properties (at least via the Oracle and Derby providers).

Am I missing something obvious?

Example:

If the setBaseProperties() call is commented out, changing the username/password has no effect.

Properties prop = connectionProfile.getBaseProperties();
prop.setProperty( PROP_USERNAME, username==null?"":username);
prop.setProperty( PROP_PASSWORD, password==null?"":password);
connectionProfile.setBaseProperties(prop);

String factoryId = connectionProfile.getProvider().getConnectionFactory("java.sql.Connection").getId();
con = connectionProfile.createConnection(factoryId,(username==null?"":username), (password==null?"":password));

//
// con will be non null even if a corresponding java.sql.Connection was not created.
//
Object rawConnection = con.getRawConnection();
Throwable e = con.getConnectException();

con.close();

if( rawConnection != null && e==null) { return; } // Connection OK

throw new Exception( e==null?"Unspecified connection error":e.getMessage());