Essential Core Java Concepts for Selenium Automation

1. Basics:

• Data Types (int, float, char, etc.)
• Variables (local, instance, static)
• Operators (arithmetic, relational, logical, bitwise)
• Type Casting

2. Control Flow Statements:

Loops:

• While
• For
• For-each (Enhanced for loop)

Conditional Statements:

• If
• If-else
• Switch

3. Object-Oriented Programming (OOP) Concepts:

• Class and Object
• Inheritance (Single, Multilevel, Hierarchical)
• Polymorphism (Method Overloading, Method Overriding)
• Encapsulation
• Abstraction (Abstract classes, Interfaces)
• Constructors
• Static and Non-static Members
• This and Super Keywords
• Final Keyword

4. Collections Framework:

• List (ArrayList, LinkedList)
• Set (HashSet, LinkedHashSet, TreeSet)
• Map (HashMap, LinkedHashMap, TreeMap)
• Queue (PriorityQueue, LinkedList)
• Iterators (Iterator, ListIterator)

5. Java Streams (Optional but Useful):

• Stream API for processing collections
• Intermediate operations (filter, map, etc.)
• Terminal operations (forEach, collect, etc.)

6. File Handling (I/O Streams):

• Reading and Writing Files
• FileInputStream, FileOutputStream
• BufferedReader, BufferedWriter
• Serialization and Deserialization

7. Exceptions Handling:

• Try, Catch, Finally
• Throw, Throws
• Custom Exceptions
• Exception Hierarchy (Checked vs Unchecked Exceptions)

8. Multithreading (Optional):

• Creating Threads (Thread class, Runnable interface)
• Thread Lifecycle
• Synchronization
• Inter-thread Communication

9. Java 8 Features (Highly Recommended):

• Lambda Expressions
• Functional Interfaces (Predicate, Consumer, Function)
• Method References
• Default and Static Methods in Interfaces
• Optional Class

10. JDBC (Optional but Useful for Database Testing):

• Basics of JDBC
• Connecting to a Database
• Executing SQL Queries
• ResultSet Handling

11. Assertions:

• Using the assert keyword
• Assertion Libraries (JUnit/TestNG)

12. Java Utilities:

• Java Time API:
  • LocalDate, LocalTime, LocalDateTime (for handling time-related operations like waiting, scheduling tests, etc.)
• File Handling:
  • File, FileReader, BufferedReader, FileWriter, BufferedWriter (for reading/writing configuration files, test data, etc.)
• Properties Class:
  • Properties (for handling configuration properties, e.g., reading browser type, URL from a config file)
• Logging Utilities:
  • Logger, FileHandler, ConsoleHandler (for creating logs that help in debugging tests)
• Regular Expressions (Regex):
  • Pattern, Matcher (for validating strings, extracting specific data from text, e.g., extracting numbers from a string)
• Random Class:
  • Random (for generating random data for test inputs, like random usernames, emails, etc.)
• Scanner Class:
  • Scanner (for reading input data from files or other sources)