Trace.java start and stop tracing

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class Trace
{

        public static void on( Connection conn )
                throws SQLException
        {
                String sql = "alter session set tracefile_identifier = tracefile";
                PreparedStatement pstmt = conn.prepareStatement( sql );
                pstmt.execute();
                sql = "alter session set events '10046 trace name context forever, level 12'";
                pstmt = conn.prepareStatement( sql );
                pstmt.execute();
        }

        public static void off( Connection conn )
                throws SQLException
        {
                String sql = "alter session set events '10046 trace name context off'";
                PreparedStatement pstmt = conn.prepareStatement( sql );
                pstmt.execute();
        }

}