Java SE 21 Programming Complete

This course provides an in-depth coverage for all core Java topics and most frequently used APIs.

It also offers a set of practical exercises teaching how to build a fully functioning Java application from scratch.

This course is intended for students with some programming experience.

1 - Introduction to Java

• Objectives 1-2
• What Is Java? 1-3
• How Java Works 1-4
• Object-Oriented Principles 1-5
• Classes and Objects 1-6
• Classes 1-7
• Objects 1-8
• Inheritance 1-9
• Java APIs 1-10
• Java Keywords, Reserved Words, and Special Identifiers 1-11
• Java Naming Conventions 1-12
• Java Basic Syntax Rules 1-13
• Defining a Java Class 1-14
• Accessing Classes Across Packages 1-15
• Implementing Encapsulation with Access Modifiers 1-17
• Creating a Main Application Class 1-18
• Compiling a Java Program 1-19
• Executing a Java Program 1-20
• Comments and Documentation 1-21
• Code Snippets in Javadoc 1-23
• External Snippets 1-24
• Summary 1-25
• Practices for Lesson 1: Overview 1-26

2 - Primitive Types, Operators, and Flow Control Statements

• Objectives 2-2
• Java Primitives 2-3
• Declaring and Initializing Primitive Variables 2-4
• Primitive Declarations and Initializations: Restrictions 2-5
• Java Operators 2-6
• Assignment and Arithmetic Operators 2-7
• Arithmetic Operations and Type Casting 2-8
• More Mathematical Operations 2-9
• Binary Number Representation 2-10
• Bitwise Logical Operators 2-11
• Equality, Relational, and Conditional Operators 2-12
• Short-Circuit Evaluation 2-13
• Flow Control Using if/else Construct 2-14
• Ternary Operator 2-15
• Flow Control Using switch Construct 2-16
• Switch -> No Fall-Through Syntax 2-17
• Switch Expressions yield a Value 2-18
• Switch Statements and Expressions Summary 2-19
• Using JShell (REPL Tool) 2-20
• JShell Commands 2-21
• Code Snippets 2-22
• Summary 2-23
• Practices for Lesson 2: Overview 2-24

3 - Text, Date, Time, and Numeric Objects

• Objectives 3-2
• String Initialization 3-3
• String Operations 3-4
• String Indexing 3-5
• Mutable Text Objects 3-6
• Text Blocks 3-7
• Spaces, Lines, and Quotes 3-9
• Wrapper Classes for Primitives 3-10
• Representing Numbers Using BigDecimal Class 3-11
• Method Chaining 3-12
• Local Date and Time API 3-13
• More Local Date and Time Operations 3-14
• Instants, Durations, and Periods 3-16
• Zoned Date and Time 3-18
• Representing Languages and Countries 3-19
• Formatting and Parsing Numeric Values 3-21
• Formatting and Parsing Date and Time Values 3-23
• Localizable Resources 3-26
• Formatting Message Patterns 3-27
• Formatting and Localization: Summary 3-29
• Summary 3-31
• Practices for Lesson 3: Overview 3-32 

4 - Classes and Objects

• Objectives 4-2
• UML: Introduction 4-3
• Modeling Classes 4-4
• Modeling Interactions and Activities 4-6
• Designing Classes 4-7
• Creating Objects 4-8
• Defining Instance Variables 4-9
• Defining Instance Methods 4-10
• Object Creation and Access: Example 4-11
• Local Variables and Recursive Object Reference 4-12
• Local Variable Type Inference 4-14
• Defining Constants 4-16
• Static Context 4-17
• Accessing Static Context 4-18
• Combining Static and Final 4-19
• Other Static Context Use Cases 4-20
• IntelliJ IDE: Introduction 4-21
• Summary 4-22
• Practices for Lesson 4: Overview 4-23 

5 - Improved Class Design

• Objectives 5-2
• Overload Methods 5-3
• Variable Number of Arguments 5-4
• Defining Constructors 5-5
• Reusing Constructors 5-6
• Access Modifiers: Summary 5-7
• Defining Encapsulation 5-8
• Defining Immutability 5-9
• Constants and Immutability 5-10
• Enumerations 5-11
• Complex Enumerations 5-13
• Java Memory Allocation 5-14
• Parameter Passing 5-15
• Java Memory Cleanup 5-16
• Summary 5-17
• Practices for Lesson 5: Overview 5-18

 6 - Implement Inheritance and Use Records

• Objectives 6-2
• Extending Classes 6-3
• Object Class 6-4
• Reusing Parent Class Code Through Inheritance 6-5
• Instantiating Classes and Accessing Objects 6-6
• Rules of Reference Type Casting 6-7
• Verifying Object Type Before Casting the Reference 6-8
• Pattern Matching for instanceof 6-9
• Reference Code Within the Current or Parent Object 6-10
• Defining Subclass Constructors 6-11
• Class and Object Initialization: Summary 6-12
• Overriding Methods and Using Polymorphism 6-13
• Reusing Parent Class Logic in Overwritten Method 6-15
• Defining Abstract Classes and Methods 6-16
• Defining Final Classes and Methods 6-17
• Sealed Classes and Interfaces 6-18
• Overriding Object Class Operations: toString 6-20
• Overriding Object Class Operations: equals 6-21
• Override Object Class Operations: hashCode 6-22
• Comparing String Objects 6-23
• Java Records 6-24
• Custom Record Constructors 6-25
• Record Patterns 6-26
• Pattern Matching for switch 6-27
• Factory Methods 6-28
• Summary 6-29
• Practices for Lesson 6: Overview 6-30

 7 - Interfaces and Generics

• Objectives 7-2
• Java Interfaces 7-3
• Multiple Inheritance Problem 7-5
• Implement Interfaces 7-6
• Default, Private, and Static Methods in Interfaces 7-7
• Interface Hierarchy 7-8
• Default Methods Inheritance 7-9
• Interface Is a Type 7-10
• Functional Interfaces 7-11
• Generics 7-12
• Use Generics 7-13
• Examples of Java Interfaces: java.lang.Comparable 7-15
• Examples of Java Interfaces: java.util.Comparator 7-16
• Examples of Java Interfaces: java.lang.Cloneable 7-17
• Composition Pattern 7-18
• Summary 7-19
• Practices for Lesson 7: Overview 7-20

 8 - Arrays and Loops

• Objectives 8-2
• Arrays 8-3
• Combined Declaration, Creation, and Initialization of Arrays 8-4
• Multidimensional Arrays 8-5
• Copying Array Content 8-6
• Arrays Class 8-7
• Loops 8-8
• Processing Arrays by Using Loops 8-9
• Complex for Loops 8-10
• Embedded Loops 8-11
• Break and Continue 8-12
• Summary 8-13
• Practices for Lesson 8: Overview 8-14

 9 - Collections

• Objectives 9-2
• Introduction to Java Collection API 9-3
• Java Collection API Interfaces 9-4
• Java Collection API Implementation Classes 9-5
• Java Collection API Interfaces and Implementation Classes 9-6
• Create List Object 9-7
• Manage List Contents 9-8
• Create Set Object 9-9
• Manage Set Contents 9-11
• Create Deque Object 9-12
• Manage Deque Contents 9-13
• Create HashMap Object 9-15
• Manage HashMap Contents 9-16
• Iterate Through Collections 9-17
• Sequenced Collections 9-18
• Other Collection Behaviors 9-20
• Use java.util.Collections Class 9-21
• Access Collections Concurrently 9-22
• Prevent Collections Corruption 9-23
• Legacy Collection Classes 9-25
• Summary 9-26
• Practices for Lesson 9: Overview 9-27

 10 - Nested Classes and Lambda Expressions

• Objectives 10-2
• Types of Nested Classes 10-3
• Static Nested Classes 10-6
• Member Inner Classes 10-7
• Local Inner Classes 10-9
• Anonymous Inner Classes 10-10
• Anonymous Inner Classes and Functional Interfaces 10-12
• Understand Lambda Expressions 10-13
• Define Lambda Expression Parameters and Body 10-14
• Use Method References 10-15
• Default and Static Methods in Functional Interfaces 10-16
• Use Default and Static Methods of the Comparator Interface 10-17
• Use Default and Static Methods of the Predicate Interface 10-18
• Summary 10-19
• Practices for Lesson 10: Overview 10-20 

11 - Java Streams API

• Objectives 11-2
• Characteristics of Streams 11-3
• Create Streams Using Stream API 11-4
• Stream Pipeline Processing Operations 11-5
• Using Functional Interfaces 11-6
• Primitive Variants of Functional Interfaces 11-7
• Bi-argument Variants of Functional Interfaces 11-9
• Perform Actions with Stream Pipeline Elements 11-10
• Perform Filtering of Stream Pipeline Elements 11-11
• Perform Mapping of Stream Pipeline Elements 11-12
• Join Streams Using flatMap Operation 11-13
• Other Intermediate Stream Operations 11-14
• Short-Circuit Terminal Operations 11-15
• Process Stream Using count, min, max, sum, average Operations 11-16
• Aggregate Stream Data using reduce Operation 11-17
• General Logic of the collect Operation 11-19
• Using Basic Collectors 11-20
• Perform a Conversion of a Collector Result 11-21
• Perform Grouping or Partitioning of the Stream Content 11-22
• Mapping and Filtering with Respect to Groups or Partitions 11-23
• Parallel Stream Processing 11-25
• Parallel Stream Processing Guidelines 11-26
• Restrictions on Parallel Stream Processing 11-27
• Spliterator 11-28
• Spliterator Characteristics 11-29
• Summary 11-30
• Practices for Lesson 11: Overview 11-31

 12 - Exception Handling, Logging, and Debugging

• Objectives 12-2
• Using Java Logging API 12-3
• Logging Method Categories 12-4
• Guarded Logging 12-5
• Log Writing Handling 12-6
• Logging Configuration 12-7
• Describe Java Exceptions 12-8
• Create Custom Exceptions 12-9
• Throwing Exceptions 12-10
• Catching Exceptions 12-11
• Exceptions and the Execution Flow 12-12
• Helpful NullPointerExceptions 12-13
• Example Throwing an Unchecked Exception 12-14
• Example Throwing a Checked Exception 12-15
• Handling Exceptions 12-16
• Resource Auto-Closure 12-17
• Suppressed Exceptions 12-18
• Handle Exception Cause 12-19
• Java Debugger 12-20
• Debugger Actions 12-21
• Manipulate Program Data in Debug Mode 12-22
• Validate Program Logic Using Assertions 12-23
• Normal Program Flow with No Exceptions 12-24
• Program Flow Producing a Runtime Exception 12-26
• Program Flow Catching Specific Checked Exception 12-28
• Program Flow Catching Any Exceptions 12-30
• Summary 12-32
• Practices for Lesson 12: Overview 12-33

 13 - Java IO API

• Objectives 13-2
• Java Input-Output Principals 13-3
• Java Input-Output API 13-4
• Reading and Writing Binary Data 13-5
• Basic Binary Data Reading and Writing 13-6
• Reading and Writing Character Data 13-7
• Basic Character Data Reading and Writing 13-8
• Connecting Streams 13-9
• Standard Input and Output 13-10
• Using Console 13-11
• Understand Serialization 13-13
• Serializable Object Graph 13-14
• Object Serialization 13-15
• Serialization of Sensitive Information 13-16
• Customize Serialization Process 13-17
• Serialization and Versioning 13-18
• Working with Filesystems 13-19
• Constructing Filesystem Paths 13-20
• Navigating the Filesystem 13-21
• Analyze Path Properties 13-22
• Set Path Properties 13-23
• Create Paths 13-24
• Create Temporary Files and Folders 13-25
• Copy and Move Paths 13-26
• Delete Paths 13-27
• Handle Zip Archives 13-28
• Represent Zip Archive as a FileSystem 13-29
• Access HTTP Resources 13-31
• Summary 13-32
• Practices for Lesson 13: Overview 13-33

 14 - Java Concurrency and Multithreading

• Objectives 14-2
• Java Concurrency Concepts 14-3
• Implement Threads 14-4
• Thread Life Cycle 14-5
• Interrupt Thread 14-6
• Block Thread 14-7
• Make Thread Wait Until Notified 14-8
• Common Thread Properties 14-10
• Create Executor Service Objects 14-11
• Manage Executor Service Life Cycle 14-14
• Implementing Executor Service Tasks 14-16
• Locking Problems 14-18
• Writing Thread-Safe Code 14-19
• Ensure Consistent Access to Shared Data 14-21
• Nonblocking Atomic Actions 14-22
• Ensure Exclusive Object Access Using Intrinsic Locks 14-23
• Intrinsic Lock Automation 14-24
• Nonblocking Concurrency Automation 14-25
• Alternative Locking Mechanisms 14-26
• CPU Versus IO Bound Concurrent Tasks 14-27
• Virtual Threads API 14-28
• Virtual Thread Operations 14-29
• Summary 14-30
• Practices for Lesson 14: Overview 14-31

 15 - Modules and Deployment

• Objectives 15-2
• Compile, Package, and Execute Nonmodular Java Applications 15-3
• Nonmodular Java Characteristics 15-4
• What Is a Module? 15-5
• Java Modules 15-7
• Java Module Categories 15-8
• Define Module Dependencies 15-9
• Export Module Content 15-10
• Module Example 15-11
• Open Module Content 15-12
• Open an Entire Module 15-13
• Produce and Consume Services 15-14
• Services Example 15-15
• Multi-Release Module Archives 15-16
• Compile and Package a Module 15-17
• Execute a Modularized Application 15-18
• Migrating Legacy Java Applications Using Automatic module 15-19
• Create Custom Runtime Image 15-20
• Execute Runtime Image 15-22
• Optimize a Custom Runtime Image 15-23
• Check Dependencies 15-24
• Summary 15-25
• Practices for Lesson 15: Overview 15-26

 A - Annotations

• Objectives A-2
• Annotations: Introduction A-3
• Design Annotations A-4
• Apply Annotations A-5
• Dynamically Discover Annotations A-6
• Document the Use of Annotations A-7
• Annotations that Validate Design A-8
• Deprecated Annotation A-9
• Suppress Compiler Warnings A-10
• Varargs and Heap Pollution A-11
• Summary A-12

 B - Java Database Connectivity

• Objectives B-2
• Java Database Connectivity (JDBC) B-3
• JDBC API Structure B-4
• Manage Database Connections B-5
• Create and Execute Basic SQL Statements B-6
• Create and Execute Prepared SQL Statements B-7
• Create and Execute Callable SQL Statements B-8
• Process Query Results B-9
• Control Transactions B-11
• Discover Metadata B-12
• Customize ResultSet B-13
• Set Up ResultSet Type B-14
• Set Up ResultSet Concurrency and Holdability B-16
• Summary B-17

 C - Java Security

• Objectives C-2
• Security as Nonfunctional Requirement C-3
• Security Threats C-4
• Denial of Service (DoS) Attack C-5
• Define Security Policies C-6
• Changes in the Security API C-8
• Secure File System and I/O Operations C-9
• Best Practices for Protecting Your Code C-10
• Erroneous Value Guards C-11
• Protect Sensitive Data (Part 1) C-12
• Protect Sensitive Data (Part 2) C-13
• Prevent SQL Injections C-14
• Prevent JavaScript Injections C-15
• Prevent XML Injections C-16
• Discover and Document Security Issues C-17
• Summary C-18 

D - Advanced Generics

• Objectives D-2
• Compiler Erases Information About Generics D-3
• Generic and Raw Type Compatibility D-4
• Generics and Type Hierarchy D-5
• Wildcard Generics D-6
• Upper Bound Wildcard D-7
• Lower Bound Wildcard D-8
• Collections and Generics Best Practices D-9
• Summary D-10

 E - Java Applications on Oracle Cloud

• Objectives E-2
• Cloud Application Requirements E-3
• Cloud Application Runtime Infrastructure E-4
• Cloud Java Application Servers E-5
• Package and Deploy Cloud Application E-6
• Optimise deployment with GraalVM E-7
• HTTP Protocol Basics E-9
• REST Service Conventions and Resources E-11
• Configure and Launch REST Service Application Using Helidon SE E-12
• Summary E-13 

F - Miscellaneous Java Topics

• Objectives F-2
• Builder Design Pattern F-3
• Singleton Design Pattern F-4
• Java Regular Expression API F-5
• Regular Expressions: Character Classes F-6
• Regular Expressions: Quantifiers F-7
• Regular Expressions: Boundaries F-8
• File IO Watch Service F-9
• Summary F-11