Java OCP 17 Study Guide

A comprehensive study repository for the Oracle Certified Professional: Java SE 17 Developer (1Z0-829) exam. This repository contains well-documented code examples, exam tips, common traps, and practical demonstrations for every topic covered in the OCP Java 17 certification.

📚 Why This Repository?

• Exam-Focused: Every example is designed with the exam in mind, highlighting common traps and edge cases
• Comprehensive Coverage: All exam topics from the official Oracle study guide
• Working Examples: All code compiles and runs, with output demonstrations
• Clear Documentation: Extensive inline comments explaining concepts and exam tips
• Quick Reference: Tables, comparisons, and checklists for rapid review
• Best Practices: Follows Java 17 features and modern coding standards

🎯 Exam Topics Covered

Chapter 1: Building Blocks

Topics: Java basics, primitive types, text blocks, operators, and fundamental concepts

• Text blocks (Java 13+)
• Variable declarations and initialization
• Primitive types and wrapper classes
• Identifier naming rules

Chapter 2: Operators

Topics: All Java operators and operator precedence

• Arithmetic, relational, and logical operators
• Operator precedence and associativity
• Short-circuit evaluation
• Ternary operator

Chapter 3: Control Flow

Topics: Decision structures and loops

• if/else statements
• switch statements (traditional and enhanced)
• for, while, and do-while loops
• break, continue, and return

Chapter 4: Core APIs

Topics: String, StringBuilder, Arrays, Math, and common APIs

• String manipulation and immutability
• StringBuilder vs StringBuffer
• Array operations
• Math class methods
• Date/Time API basics

Chapter 5: Methods

Topics: Method declarations, overloading, varargs

• Method signatures and return types
• Method overloading rules
• Varargs (variable arguments)
• Access modifiers
• Static vs instance methods

Chapter 6: Inheritance

Topics: Class inheritance, polymorphism, abstract classes

• extends keyword and inheritance hierarchy
• Method overriding vs overloading
• Abstract classes and methods
• Polymorphism and casting
• Object class methods

Chapter 7: Beyond Classes

Topics: Interfaces, enums, nested classes, sealed classes

• Interface declarations and implementation
• Default and static methods in interfaces
• Private methods in interfaces
• Enums with constructors and methods
• Inner classes (static nested, inner, local, anonymous)
• Sealed classes (Java 17)

Chapter 8: Lambdas and Functional Interfaces

Topics: Lambda expressions, method references, built-in functional interfaces

• Lambda syntax and rules
• Functional interface definitions
• Method references (4 types)
• Built-in functional interfaces (Predicate, Consumer, Supplier, Function)
• Effectively final variables
• Lambda parameter syntax including var (Java 11+)

Chapter 9: Collections and Generics

Topics: Collection framework, generics, comparators

• Files:
  • CollectionsFramework.java - Overview of List, Set, Queue, Map
  • ListMethods.java - List operations and methods
  • SetMethods.java - Set implementations and methods
  • MapMethods.java - Map operations and methods
  • QueueAndDequeMethods.java - Queue/Deque operations
  • ComparableAndComparator.java - Sorting and comparison
  • GenericsAndTypeErasure.java - Generic types and type erasure
  • BoundingGenericTypes.java - Bounded wildcards (upper/lower bounds)

Chapter 10: Streams

Topics: Stream API, intermediate and terminal operations

• Stream creation and operations
• map, filter, reduce, collect
• Optional class
• Primitive streams
• Stream pipeline evaluation

Chapter 11: Exceptions and Localization

Topics: Exception handling, try-with-resources, localization

• Checked vs unchecked exceptions
• try-catch-finally blocks
• try-with-resources (AutoCloseable)
• Multi-catch blocks
• Custom exceptions
• Localization and resource bundles

Chapter 12: Modules

Topics: Java Platform Module System (JPMS)

• Module declarations
• exports and requires
• Module types
• Module path vs classpath
• Service loading

Chapter 13: Concurrency

Topics: Threads, concurrency utilities, parallel streams

• Thread creation and lifecycle
• ExecutorService and thread pools
• Concurrent collections
• Atomic classes
• Locks and synchronization
• Parallel streams

Chapter 14: I/O

Topics: File I/O, NIO.2, serialization

• Files:
  • FileAndPathBasics.java - File and Path fundamentals
  • FilesOperations.java - Files class operations
  • NIO2Options.java - LinkOption, StandardCopyOption, StandardOpenOption
  • Stream-based I/O
  • File operations and directory walking

Chapter 15: JDBC ⭐

Topics: Database connectivity, SQL operations, transactions

• Complete implementation with 7 files and comprehensive documentation
• Files:
  1. JDBCBasics.java - JDBC URL, DriverManager, Connection
  2. PreparedStatementExamples.java - Execute methods, binding variables
  3. ResultSetExamples.java - Cursor navigation, getters
  4. CallableStatementExamples.java - Stored procedures, IN/OUT/INOUT
  5. TransactionsAndSavepoints.java - Transactions, commit, rollback, savepoints
  6. ClosingResources.java - Proper closing order, cascading close
  7. JDBCExamReference.java - Quick reference guide

See: src/ch15jdbc/README.md for detailed setup and usage

Key Exam Points:

• JDBC URL format: jdbc:subprotocol:subname
• Execute methods: executeUpdate(), executeQuery(), execute()
• 1-based indexing (NOT 0-based!)
• ResultSet cursor starts BEFORE first row
• Closing order: ResultSet → PreparedStatement → Connection
• Cascading close behavior
• Transaction control and savepoints

📂 Repository Structure

JavaOCP17/
├── src/
│   ├── ch01buildingblocks/
│   ├── ch02operators/
│   ├── ch03controlflow/
│   ├── ch04coreapis/
│   ├── ch05methods/
│   ├── ch06inheritance/
│   ├── ch07beyondclasses/
│   ├── ch08lambdasandfunctionalinterfaces/
│   ├── ch09collectionsandgenerics/
│   ├── ch10streams/
│   ├── ch11exceptionsandlocalization/
│   ├── ch12modules/
│   ├── ch13concurrency/
│   ├── ch14io/
│   ├── ch15jdbc/          # Complete JDBC implementation
│   │   ├── README.md      # Detailed JDBC setup and examples
│   │   ├── JDBCBasics.java
│   │   ├── PreparedStatementExamples.java
│   │   ├── ResultSetExamples.java
│   │   ├── CallableStatementExamples.java
│   │   ├── TransactionsAndSavepoints.java
│   │   ├── ClosingResources.java
│   │   ├── JDBCExamReference.java
│   │   ├── stored-procedures.sql
│   │   └── setup-procedures.bat
│   └── ch16jdbc/          # Additional JDBC examples
├── lib/
│   └── postgresql-42.7.1.jar  # JDBC driver for examples
├── docker-compose.yml     # PostgreSQL database for JDBC
├── init-db.sql           # Database initialization
└── README.md             # This file

🚀 Getting Started

Prerequisites

• Java 17 or higher
• Docker (for JDBC chapter examples)
• Git

Clone the Repository

git clone https://github.com/caseythecoder90/java-ocp-17-study.git
cd java-ocp-17-study

Compile Examples

# Compile all Java files
javac src/**/*.java

# Or compile specific chapter
javac src/ch09collectionsandgenerics/*.java

Run Examples

# Run a specific example
java -cp src ch09collectionsandgenerics.BoundingGenericTypes

# For JDBC examples (requires classpath with driver)
java -cp "src;lib/*" ch15jdbc.JDBCBasics

JDBC Setup (Chapter 15)

JDBC examples require PostgreSQL running in Docker:

# Start database
docker-compose up -d

# Setup stored procedures (one-time)
docker exec -i jdbc-practice-db psql -U ocpuser -d ocp_practice < src/ch15jdbc/stored-procedures.sql

# Run JDBC examples
java -cp "src;lib/*" ch15jdbc.JDBCBasics

See src/ch15jdbc/README.md for detailed instructions.

📖 How to Use This Repository

For First-Time Learners

1. Read the code: Each file has extensive documentation explaining concepts
2. Run the examples: See the output and understand behavior
3. Modify and experiment: Change values and see what happens
4. Note the exam traps: Pay special attention to comments marked "EXAM TRAP!"

For Exam Review

1. Focus on comparison tables: Each chapter has tables comparing similar concepts
2. Review exam traps: All common pitfalls are documented
3. Practice with edge cases: Examples include boundary conditions
4. Use quick reference files: Files like JDBCExamReference.java for rapid review

Study Approach

1. Week 1-2: Chapters 1-5 (Fundamentals)
2. Week 3-4: Chapters 6-8 (OOP and Lambdas)
3. Week 5-6: Chapters 9-11 (Collections, Streams, Exceptions)
4. Week 7-8: Chapters 12-14 (Modules, Concurrency, I/O)
5. Week 9-10: Chapter 15 (JDBC) + Practice Exams
6. Week 11: Review all exam traps and edge cases

🎓 Exam Day Checklist

Must Memorize

• JDBC URL format: jdbc:subprotocol:subname
• Execute method return types
• 1-based indexing in JDBC (NOT 0-based)
• ResultSet cursor starts BEFORE first row
• Resource closing order (reverse of creation)
• AutoCloseable and try-with-resources
• Functional interface method counts
• Collection framework hierarchy
• Stream operations (intermediate vs terminal)
• Module system basics

Common Exam Traps

• Confusing executeUpdate() with executeQuery()
• Using index 0 for JDBC parameters/columns
• Forgetting ResultSet cursor starts before first row
• Wrong closing order for JDBC resources
• Modifying effectively final variables in lambdas
• Confusing method overloading vs overriding
• Array vs Collection operations
• Checked vs unchecked exceptions

🔍 Key Features

Comprehensive Documentation

Every file includes:

• Detailed inline comments explaining each concept
• Comparison tables for similar methods/concepts
• Common exam traps clearly marked
• Edge cases and boundary conditions
• Expected output for each example

Exam-Focused Examples

• Real exam scenarios: Examples mirror actual exam question patterns
• Edge cases: Boundary conditions and special cases covered
• Common mistakes: What NOT to do, with explanations
• Quick reference: Tables and summaries for rapid review

Working Code

• All examples compile with Java 17
• All examples produce output (not just syntax demonstrations)
• JDBC examples use real database (PostgreSQL in Docker)
• No external dependencies except JDBC driver

💡 Tips for Success

1. Don't just read, code: Type out examples yourself
2. Understand the "why": Don't memorize, understand the reasoning
3. Focus on exam traps: These are heavily tested
4. Practice with real code: Run examples and modify them
5. Use comparison tables: Great for quick review
6. Review edge cases: Exam loves boundary conditions
7. Time yourself: Practice answering questions quickly

📝 What's NOT on the Exam

To help you focus, here's what you can skip:

• SQL syntax errors (only JDBC API is tested)
• Statement interface (only PreparedStatement and CallableStatement)
• DataSource (only DriverManager)
• Batch updates
• Advanced concurrency patterns
• Complex regex patterns
• GUI development
• Network programming

🤝 Contributing

Found an error or want to add examples? Contributions are welcome!

1. Fork the repository
2. Create a feature branch (git checkout -b feature/improvement)
3. Commit your changes (git commit -m 'Add improvement')
4. Push to the branch (git push origin feature/improvement)
5. Open a Pull Request

Please ensure:

• Code compiles with Java 17
• Examples include comprehensive documentation
• Exam traps are clearly marked
• Output is demonstrated

📊 Repository Statistics

• Total Java Files: 100+
• Chapters Covered: 15/15 (100%)
• Lines of Documentation: Thousands
• Working Examples: All files compile and run
• Exam Topics: Complete coverage

🙏 Acknowledgments

This repository was created as a comprehensive study guide for the Oracle Certified Professional Java SE 17 Developer exam. Examples and documentation are based on:

• Oracle's official Java SE 17 documentation
• OCP Java SE 17 Developer Study Guide
• Real exam practice questions and feedback
• Personal exam preparation experience

📜 License

This repository is for educational purposes. Feel free to use for your exam preparation.

🎯 Final Notes

Good luck on your exam! Remember:

• Understand, don't memorize
• Practice with working code
• Focus on exam traps
• Review comparison tables
• Test edge cases
• Time management is key

For JDBC examples, see the detailed guide in src/ch15jdbc/README.md.

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Last Updated: January 2026 Exam: Oracle Certified Professional: Java SE 17 Developer (1Z0-829)