Refactoring

Basics

• 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 General Issues

• Discuss the evil of duplicated code
• Discuss the problem of dead code
• Simplify conditional and other expressions

Keywords: duplicated code, dead code, magic numbers Modules

• 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 Classes

• 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 Methods

• 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 Naming and Comments

• 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 Exception Handling

• 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 Legacy Code

• 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