飞机订票系统，实现订票，退票，查询
the banking system relates to multi-threaded, socket programming, and singleton design pattern. Notes for the complete source Gilmour, documentation, together with the development process
THE DESIGN PATTERNS JAVA COMPANION
1. Creational Patterns 17
The Factory Pattern 18
How a Factory Works 18
Sample Code 18
The Two Derived Classes 19
Building the Factory 20
Factory Patterns in Math Computation 22
When to Use a Factory Pattern 24
Thought Questions 25
The Abstract Factory Pattern 26
A GardenMaker Factory 26
How the User Interface Works 28
Consequences of Abstract Factory 30
Thought Questions 30
The singleton Pattern 31
Throwing the Exception 32
Creating an Instance of the Class 32
Static Classes as singleton Patterns 33
Creating singleton Using a Static Method 34
