ruby元编程 - 获取类的方法名称和参数信息(ruby metaprogramming - getting method names and parameter info for a class)

 我会把丑陋提取到辅助方法中 
 
class StatementHelper{
    static void setDouble(int index, PreparedStatement preparedStatement, Double val) throws SQLException {
        if (val == null )
            preparedStatement.setNull(index, java.sql.Types.NULL);
        else
            preparedStatement.setDouble(index, val);
    }

    //Repeat for other data types
}
 
 然后就像那样建立你的陈述 
 
StatementHelper.setDouble(++i, ps, balance);
StatementHelper.setInt(++i, ps, someInt);
StatementHelper.setString(++i, ps, someString);
StatementHelper.setFloat(++i, ps, someFloat);
 
 这将使语句构建代码相对干净 

I would extract the ugliness into helper methods
 
class StatementHelper{
    static void setDouble(int index, PreparedStatement preparedStatement, Double val) throws SQLException {
        if (val == null )
            preparedStatement.setNull(index, java.sql.Types.NULL);
        else
            preparedStatement.setDouble(index, val);
    }

    //Repeat for other data types
}
 
and then just build your statement like that
 
StatementHelper.setDouble(++i, ps, balance);
StatementHelper.setInt(++i, ps, someInt);
StatementHelper.setString(++i, ps, someString);
StatementHelper.setFloat(++i, ps, someFloat);
 
This would keep the statement building code relatively clean