To thoroughly learn the refactorings in the catalog, you'll want to study every refactoring's example code. Because several refactorings refer to the same project, you'll find it easier to understand the refactorings if you follow them using the study sequence shown in Table 5.1.
Table 5.1.
Session
Refactoring(s)
1
Replace Constructors with Creation Methods (57)
Chain Constructors (340)
2
Encapsulate Classes with Factory (80)
3
Introduce Polymorphic Creation with Factory Method (88)
4
Replace Conditional Logic with Strategy (129)
5
Form Template Method (205)
6
Compose Method (123)
7
Replace Implicit Tree with Composite (178)
8
Encapsulate Composite with Builder (96)
9
Move Accumulation to Collecting Parameter (313)
10
Extract Composite (214)
Replace One/Many Distinctions with Composite (224)
11
Replace Conditional Dispatcher with Command (191)
12
Extract Adapter (258)
Unify Interfaces with Adapter (247)
13
Replace Type Code with Class (286)
14
Replace State-Altering Conditionals with State (166)
15
Introduce Null Object (301)
16
Inline Singleton (114)
Limit Instantiation with Singleton (296)
17
Replace Hard-Coded Notifications with Observer (236)
