Intermediate
Module 9: Advanced Core Features
Strengthen mastery of strings, regular expressions, file I/O, NIO.2, and Optional-driven APIs.
String Pool & Memory Management
Understand interning, immutability, and when to reach for StringBuilder.
StringBuilder vs StringBuffer
Pick the correct mutable string class for single-threaded or synchronized scenarios.
Formatting & Localization
Use `String.format`, `Formatter`, and `NumberFormat` for human-friendly output.
Regular Expressions, Pattern & Matcher
Parse text with regex using the Pattern/Matcher APIs.
File I/O with java.io
Read, write, and buffer text/binary streams using the classic IO APIs.
Modern I/O with NIO.2
Leverage `Path`, `Files`, and stream-based directory walking.
Serialization Basics
Persist object graphs responsibly using Java serialization or modern alternatives.
Optional Usage Patterns
Model absence safely with Optional while avoiding anti-patterns.
Mini-Project: Log File Analyzer
Parse large log files, extract metrics, and output summaries using regex and NIO.2 streams.