如何查明获得的Java ResultSet是否为空?

Class.forName("org.sqlite.JDBC");
Connection conn =
    DriverManager.getConnection("jdbc:sqlite:userdata.db");
Statement stat = conn.createStatement();

ResultSet rs = stat.executeQuery("SELECT * from table WHERE is_query_processed = 0;");

int rowcount = rs.getRow(); 
System.out.println("Row count = "+rowcount); // output 1

rs.first(); // This statement generates an exception
Class.forName("org.sqlite.JDBC");
Connection co