Java, No Tears

Preface

This book teaches students how to program in Java with small, runnable examples. The main examples target JDK 25, the current long-term support baseline. To follow along and execute the code samples, you will need Docker installed. The Docker container is located on Docker Hub. After you have installed Docker, you may run the container as follows.

docker run -it \
 -p 8888:8888 \
 oneoffcoder/book-java-intro

Note that this Docker container has Jupyter Lab running on port 8888. You may access Jupyter Lab at http://localhost:8888 when the Docker container is running.

The diagram below summarizes the learning path through the Java material, starting with setup and syntax before moving into object-oriented design, project workflow, libraries, runtime behavior, modern idioms, and practice.

That roadmap is useful when you are skimming the book: the early chapters establish the language itself, the middle chapters focus on modeling and project structure, and the later chapters show how Java code behaves in larger, real programs.

Start Here

• 1. Getting Started
  • 1.1. Version baseline
  • 1.2. Running compact source files
  • 1.3. Running with Docker
  • 1.4. Running with Maven
  • 1.5. Reading examples in this book
• 2. Hello, World!
  • 2.1. Compact source file
  • 2.2. Growing the program
  • 2.3. Classic main method

Core Syntax

• 1. Types
  • 1.1. Basic Types
  • 1.2. Arrays
  • 1.3. Type inference with var
  • 1.4. String
• 2. Operators
  • 2.1. Basic arithmetic operators
  • 2.2. Unary operators
  • 2.3. Compound assignment operators
  • 2.4. Bitwise operators
  • 2.5. Relational operators
  • 2.6. Boolean logical operators
  • 2.7. Parentheses
• 3. Control Statements
  • 3.1. if-else
  • 3.2. if-elseif-else
  • 3.3. Nested if-else
  • 3.4. switch
  • 3.5. Nested switch
  • 3.6. Arrow syntax for switch
  • 3.7. Switch expressions
• 4. Loops
  • 4.1. while
  • 4.2. do-while
  • 4.3. for
  • 4.4. for-each
  • 4.5. Jump statements

Object-Oriented Java

• 1. Classes
  • 1.1. Basic
  • 1.2. Getters and setters
  • 1.3. Method overriding
  • 1.4. Method with logic
  • 1.5. Static Method
  • 1.6. Methods with variable-length arguments
  • 1.7. Inheritance
  • 1.8. Interface
• 2. Generics
  • 2.1. Basic generic
  • 2.2. Generic with two types
  • 2.3. Generic with bounded type
  • 2.4. Generic with wild card
  • 2.5. Generic interface
• 3. Enumerations
  • 3.1. Basic
  • 3.2. Using valueOf
  • 3.3. Enumeration class
• 4. Annotations
  • 4.1. Marker
  • 4.2. With fields
  • 4.3. Target
  • 4.4. Repeatable

Project Workflow

• 1. Packages, Maven, and Project Layout
  • 1.1. Source directories
  • 1.2. Packages
  • 1.3. Imports
  • 1.4. Module imports
  • 1.5. Maven project files
  • 1.6. Common Maven commands
• 2. Testing
  • 2.1. Running tests
  • 2.2. The existing test harness
  • 2.3. A small unit test
  • 2.4. Testing exceptions

Libraries and Runtime

• 1. Libraries
  • 1.1. Math
  • 1.2. StringBuilder
  • 1.3. HTTP
  • 1.4. CSV
  • 1.5. Static imports
  • 1.6. String tokenization
  • 1.7. Optional
  • 1.8. Date
  • 1.9. Random number generation
• 2. Modern Date and Time
  • 2.1. Dates and times
  • 2.2. Instants and time zones
  • 2.3. Durations and periods
  • 2.4. Formatting and parsing
• 3. Collections
  • 3.1. List
  • 3.2. Set
  • 3.3. Map
• 4. Lambdas
  • 4.1. Functional interface
  • 4.2. Generic functional interface
  • 4.3. Block lambda
  • 4.4. Lambda as argument
  • 4.5. Lambda parameters with var
  • 4.6. Variable capture
  • 4.7. Predefined functional interfaces
• 5. Streams
  • 5.1. Integer streams
  • 5.2. Map, filter, reduce
  • 5.3. Flat map
  • 5.4. Collecting streams
  • 5.5. Stream to list
• 6. Exceptions
  • 6.1. Divide by zero example
  • 6.2. try-catch
  • 6.3. throw
  • 6.4. try-catch-finally
  • 6.5. try-catch with resources
  • 6.6. try-with-resources with an existing variable
• 7. Threading
  • 7.1. Virtual threads
  • 7.2. Scoped values
  • 7.3. Different ways to create threads
  • 7.4. Multiple threads
  • 7.5. Timer and TimerTask
  • 7.6. Executor
  • 7.7. Callable
  • 7.8. Sharing a variable across threads
  • 7.9. Fork/Join and Recursive Task
• 8. Input/Output (IO)
  • 8.1. Path and Files
  • 8.2. Writing to a file
  • 8.3. Reading from a file

Modern Java

• 1. Modern Java Idioms
  • 1.1. Records for data
  • 1.2. Sealed hierarchies
  • 1.3. Pattern matching
  • 1.4. Module imports
  • 1.5. Flexible constructor bodies
  • 1.6. Unnamed variables and patterns
  • 1.7. Compact source files
• 2. JDK 26 Preview Notes
  • 2.1. Primitive patterns
  • 2.2. HTTP/3
  • 2.3. Structured concurrency
  • 2.4. Migration notes

Optional Tools

• 1. Optional Tools
  • 1.1. Lombok
  • 1.2. Tuples

Practice

• 1. Debugging and Logging
  • 1.1. Compiler errors
  • 1.2. Runtime exceptions
  • 1.3. Printing values
  • 1.4. Assertions
  • 1.5. Basic logging
• 2. Exercises and Mini-Projects
  • 2.1. Syntax practice
  • 2.2. Object practice
  • 2.3. Collection practice
  • 2.4. Streams practice
  • 2.5. Modern Java practice
  • 2.6. Mini-project: gradebook
  • 2.7. Mini-project: contact manager

About

One-Off Coder is an educational, service and product company. Please visit us online to discover how we may help you achieve life-long success in your personal coding career or with your company’s business goals and objectives.

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Copyright

This work is licensed under a Creative Commons Attribution 4.0 International License by One-Off Coder.



The full source code is available on GitHub.

Cite this book as follows.:

@misc{oneoffcoder_java_intro_2019,
title={Java, No Tears},
url={https://learn-java.oneoffcoder.com},
author={One-Off Coder},
year={2019},
month={Oct}}

Author

Jee Vang, Ph.D.

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