[3.0] Improve error message when asking for a JDBC connection

hibernate-reactive-core/src/main/java/org/hibernate/reactive/logging/impl/Log.java

@@ -7,6 +7,7 @@
 
 
 
+import java.sql.SQLException;
 import java.sql.SQLWarning;
 
 import jakarta.persistence.PersistenceException;
@@ -266,6 +267,9 @@ public interface Log extends BasicLogger {
 	@Message(id = 83, value = "Unexpected request of a non reactive connection")
 	HibernateException unexpectedConnectionRequest();
 
+	@Message(id = 84, value = "The application requested a JDBC connection, but Hibernate Reactive doesn't use JDBC. This could be caused by a bug or the use of an unsupported feature in Hibernate Reactive")
+	SQLException notUsingJdbc();
+
 	// Same method that exists in CoreMessageLogger
 	@LogMessage(level = WARN)
 	@Message(id = 104, value = "firstResult/maxResults specified with collection fetch; applying in memory!" )

hibernate-reactive-core/src/main/java/org/hibernate/reactive/provider/service/NoJdbcConnectionProvider.java

@@ -6,23 +6,28 @@
 package org.hibernate.reactive.provider.service;
 
 import org.hibernate.engine.jdbc.connections.spi.ConnectionProvider;
+import org.hibernate.reactive.logging.impl.Log;
 
 import java.sql.Connection;
 import java.sql.SQLException;
 
+import static java.lang.invoke.MethodHandles.lookup;
+import static org.hibernate.reactive.logging.impl.LoggerFactory.make;
+
 /**
  * A dummy Hibernate {@link ConnectionProvider} throws an
  * exception if a JDBC connection is requested.
  *
  * @author Gavin King
  */
 public class NoJdbcConnectionProvider implements ConnectionProvider {
+	private static final Log LOG = make( Log.class, lookup() );
 
 	public static final NoJdbcConnectionProvider INSTANCE = new NoJdbcConnectionProvider();
 
 	@Override
 	public Connection getConnection() throws SQLException {
-		throw new SQLException( "Not using JDBC" );
+		throw LOG.notUsingJdbc();
 	}
 
 	@Override