Clocking the eighth day
How time flies, the distance began to write blog has in the past week ......... ado it, take inventory of the contents of today's study.
First morning two classes, the first design pattern described in detail in the factory mode and the simple mode factory method, the first mode is a simple plant, which body is divided into three categories, namely: an abstract class (base class), factory class factory subclass (inherited from the base class). Factory class factory method is mainly determined by the parameters of the plant subclass. The advantage is not need to know the method name and its contents, know their arguments. Structured very clear. There are drawbacks, however, are not in line with our principle of opening and closing, because if you want to increase the subclasses need to increase the sentence to determine the factory method. So there have been factory method pattern, according to our Richter substitution principle to find what caused the change and its abstraction of, we know that this program appear initiate change is the factory class, so we have to abstract, and come out of it concrete subclasses. This not only reduces their workload, but also respect for the principle of opening and closing. The basic content of the whole class is here, of course, a large part of the time on the show is the code to achieve, not repeat them here (in fact, I do not know, there are many places, especially the teacher said reflection xml, which remain after Thursday I to do the experiment in the open to say) this lesson teacher also interspersed with a lot of other things, such as uml arrows, such as nodepad ++, and a little knowledge of computers depth study of (python front-end + c ++ background) only briefly here memories (uml had a good look)
Director lesson focuses yes yes right from the start to the completion of the software requirements analysis outlined such a process, which talked about the grading scale software, software flow chart drawing (a little bit). I wrote about some think it is quite important (for example, mentions to write a lot of look professional, what have goals that measure, the relevant contents of such benefits) there is a very important one, is the context of the tender map introduction, context diagram of introduction, is clearly a major draw this map process, first of all clear what subject, followed by a clear data flow, data flow and then only cover up the black box in the contents of the internal flow of the system, so that we can draw out a more qualified view of the context, and its main purpose is to define the scope and limits of our software.
Afternoon slept. . . . Should have two points to the results of the study hall, eyes open four o'clock, sin a sin. Yesterday did not complete the configuration of mapreduce problem later, mainly do not know why my ubanton system permissions are set to the system, using a variety of methods are not the solution (a problem I do not know the system, do not rely on answers or online spectrum) later found no sudo, but into the administrator mode directly su can avoid this problem. (And I spent a lot of time and effort ... the mentality of explosion)