Java Clean Code: How to Write Clean Code in Java (JAV6)

Course content:

• Clean Code
1. What is bad code and its consequences for a project
2. The Boy Scout Rule, Javadoc @author

• Meaningful names
1. Names that reveal intent; pronounceable and searchable names
2. Class and method names; how to avoid confusion and ambiguity
3. Use domain terms; one word per concept rule
4. Meaningful and justified context

• Functions
1. Small, single-purpose functions; one level of abstraction
2. Function parameters: one, two and many parameters
3. Side effects and unintended behavior of functions
4. Exceptions vs error codes; correct use of switch
5. DRY principle; preventing code duplication

• Comments
1. Prefer documenting by writing clear code
2. Examples of good comments
3. Examples of bad comments

• Code formatting
1. Purpose of formatting and team formatting rules
2. Vertical formatting
3. Horizontal formatting

• Handling error states
1. Use exceptions; start with try-catch-finally pattern
2. Unchecked exceptions; add context for the caller
3. Principle of not returning or passing null

• System boundaries
1. Using third-party code; the Adapter design pattern
2. Discovering system boundaries; learning tests; keeping boundaries clear

• Unit tests
1. The three laws of TDD; BDD
2. Clean tests: one test per concept; refactoring tests
3. Using JUnit, Mockito and AssertJ

• Classes
1. Class organization; small classes; structure ready for change
2. Single Responsibility Principle (SRP)
3. Objects vs data structures; the Law of Demeter

• Systems
1. Separate system construction from usage; separate responsibilities
2. Scaling, AOP, optimizing decision logic
3. Test-driven system architecture design

• Parallel processing
1. When concurrency makes sense; challenges of parallelism
2. Defensive programming for concurrency
3. Importance of understanding chosen technology and computation models
4. Rules for small critical sections; issues with shutdown routines
5. Testing multithreaded code