Refactoring

This exam focuses on Refactoring. For successfully pass this exam the students must be able to:

identify why some code samples are suboptimal
improve some code samples
understand why refactoring is crucial in the development process
understand in which steps of the development process refactoring is applied
understand common code smells

The following readings are recommended for this exam:

Refactoring: Improving the Design of Existing Code by Martin Fowler et al.
Clean Code: A Handbook of Agile Software Craftsmanship by Robert C. Martin
Effective Java: A Programming Language Guide by Joshua Bloch

Other useful resources in the net are:

Note: For the code samples the scope of API and frameworks that can be used in the questions is restricted to Java SE 6. Not covered are JUnit test anti-patterns and refactoring. This topic is covered by the JUnit Intermediate Exam.

	Released	Beta	Frozen
Basics 3 questions Explain why code should be refactored Explain why readability of code is crucial Discuss the scope of code to be refactored Differentiate refactoring with agile development Show the relation of refactoring and maintenance effort Discuss the relations between refactoring and testing Explain what an anti-pattern is Define a code smell Keywords: code smell, anti-pattern, agile development, test driven development, testing, clean code	11	1	1	Add a question Beta questions
General Issues 2 questions Discuss the evil of duplicated code Discuss the problem of dead code Simplify conditional and other expressions Keywords: duplicated code, dead code, magic numbers	7	0	1	Add a question Beta questions
Modules 4 questions Discuss the appropriateness of dependencies between classes Discuss the problem of divergent changes Detect the possibility to refactor existing code to use polymorphismus Keywords: feature envy, data clumps, primitive obsession, parallel inheritance hierarchy, message chains, middle man, refused bequest, incomplete library class, coupling, divergent changes, shotgun surgery, switch statements, speculative generality	12	1	1	Add a question Beta questions
Classes 2 questions Examine the cohesion of a class Identify classes having more than one responsibility Examine the length of a class Keywords: large class, lazy class, temporary fields, inappropriate intimacy, inappropriate static, value object	7	1	0	Add a question Beta questions
Methods 2 questions Examine the levels of abstraction used inside a method Examine the proper size and length of lines and methods Classify the parameter list of a method Examine the type of parameters Keywords: long method, long parameter list, output arguments, flag arguments, level of abstraction	5	1	1	Add a question Beta questions
Naming and Comments 2 questions Review proper naming for variables, fields, properties, function and classes Examine the expressiveness of the name of an element compared to what the code really does Distinguish between appropriate and inappropriate comments Keywords: expressiveness, naming convention, inappropriate information, obsolete comment, redundant comment, poorly written comment, commented-out code	6	3	0	Add a question Beta questions
Exception Handling 2 questions Identify awkward exception handling strategy Explain why using flags to indicate an exceptional state is suboptimal Detect the difficulties of using null in the scope of an exceptional program state Keywords: flags, try-catch-ignore, null	6	0	0	Add a question Beta questions
Legacy Code 3 questions Improve legacy code to use state of the art API (Java 1.6) Identify obsolete patterns (Java 1.4 and previous) Determine flawed and ineffective code caused by improper use of the API Keywords: enum, static imports, for each, generics, boxing, unboxing, varargs Note: Do not add any questions about Java 5 features without a clear relation how the problem has been solved with Java 1.4	10	0	0	Add a question Beta questions