Thinking in Patterns with Java V0.9: Chapter 1: introduction: TIPatterns.htm#_Toc41169679
1, The sections name of today's learning;
The Y2K syndrome. 11
Context and composition. 12
A word about checked exceptions 13
2, What is it talk about in these sections?
Even my english is poor, but in order to learn it, I will write some my viewpoints of the content. After finishing read this book once, and to see a chinese version of this book, maybe I will rewrite some words at here.
First, I am amused the term GoF is conerned with that well-known four persons in China include JiangQing, WangHongWen, etc..
The first part tells us, you must have learned some basic OOP and have used Java some time, then you can read this book, it isn't for a beginer of Java or program.
In section The Y2K syndrome, it tells us, focus on the key that is really the bottleneck of system, usually, only 10% code is this key, don't perform some optimization according to your own thinking without deeply testing. I think Bruce put these words at this location of this book, the meaning maybe is Design Patterns can be used at the key part of system(only 10%), for non-key part, you don't think the Design Patterns should be used everywhere.
Bruce introduces two terms which is Context and composition, maybe he thought these two terms is very important in the Design Patterns? Because I haven't read some basic knowledge about Design Patterns, so I can't understand these two terms well. But I should remeber these words: "The context object allows you to use the pattern in a composition, and that may be it’s primary value.". Maybe I can understand these after reading this book.
In fact, I don't think Bruce should put the content about "checked exceptions" at here, to Design Patterns, how important the "checked exceptins" is? In these part, I know Bruce discontented the "checked exceptions" in C++ and Java except Python. This part I can't understand it well, but I can get one is: "I intend to put a lot more RuntimeExceptions into my Java code".
3, My comments and feeling for the content?
no.
4, My questions about the program itself;
1), What on earth is Context object in the Design Patterns ?
5, My questions about the english language;
1), Strange words:
evolve, rudimentary, syndrome, subtitle, pitfall, terms, as far as, predicting doom, as if, premature, virtually, happen, particular, facade, knowledge, silly, past, dominate, landscape, turn around, intrude, go up, vanish, ream, opposite, tongue-in-cheek, widow, demonize, chronicle
2), Strange sentences:
Y2K syndrome:
1>, Also,everyone seems to reserve in their own mind a special case ?except for this thing that I happen to know is a particular problem.?
2>, these things aren?t so difficult after all, if I can see such an obvious problem.
3>, As a result, I know that many
embedded systems have no idea what the date or time is, and even if they do
that data often isn?t used in any important calculations. And yet I was told in
no uncertain terms that all the embedded systems were going to crash on January
1, 2000. As far as I can tell the only memory that was lost on that particular
date was that of the people who were predicting doom ? it?s as if they had
never said any of that stuff.
4>, ?We should forget about small efficiencies, say about 97% of the time:
Premature optimization is the root of all evil.??Donald Knuth
5>, My experience with Python exceptions supports this, and unless I get turned around on this issue I intend to put a lot more RuntimeExceptions into my Java code.
incomplete