Introduction to Java

Objectives

What Is Java?

How Java Works

Object-Oriented Principles

Classes and Objects

Classes

Objects

Inheritance

Java APIs

Java Keywords, Reserved Words, and Special Identifiers

Java Naming Conventions

Java Basic Syntax Rules

Defining a Java Class

Accessing Classes Across Packages

Implementing Encapsulation with Access Modifiers

Creating a Main Application Class

Compiling a Java Program

Executing a Java Program

Comments and Documentation

Code Snippets in Javadoc

External Snippets

Summary

Practices for Lesson 1: Overview

Primitive Types, Operators, and Flow Control Statements

Objectives

Java Primitives

Declaring and Initializing Primitive Variables

Primitive Declarations and Initializations: Restrictions

Java Operators

Assignment and Arithmetic Operators

Arithmetic Operations and Type Casting

More Mathematical Operations

Binary Number Representation

Bitwise Logical Operators

Equality, Relational, and Conditional Operators

Short-Circuit Evaluation

Flow Control Using if/else Construct

Ternary Operator

Flow Control Using switch Construct

Switch -> No Fall-Through Syntax

Switch Expressions yield a Value

Switch Statements and Expressions Summary

Using JShell (REPL Tool)

JShell Commands

Code Snippets

Summary

Practices for Lesson 2: Overview

Text, Date, Time, and Numeric Objects

Objectives

String Initialization

String Operations

String Indexing

Mutable Text Objects

Text Blocks

Spaces, Lines, and Quotes

Wrapper Classes for Primitives

Representing Numbers Using BigDecimal Class

Method Chaining

Local Date and Time API

More Local Date and Time Operations

Instants, Durations, and Periods

Zoned Date and Time

Representing Languages and Countries

Formatting and Parsing Numeric Values

Formatting and Parsing Date and Time Values

Localizable Resources

Formatting Message Patterns

Formatting and Localization: Summary

Summary

Practices for Lesson 3: Overview

Classes and Objects

Objectives

UML: Introduction

Modeling Classes

Modeling Interactions and Activities

Designing Classes

Creating Objects

Defining Instance Variables

Defining Instance Methods

Object Creation and Access: Example

Local Variables and Recursive Object Reference

Local Variable Type Inference

Defining Constants

Static Context

Accessing Static Context

Combining Static and Final

Other Static Context Use Cases

IntelliJ IDE: Introduction

Summary

Practices for Lesson 4: Overview

Improved Class Design

Objectives

Overload Methods

Variable Number of Arguments

Defining Constructors

Reusing Constructors

Access Modifiers: Summary

Defining Encapsulation

Defining Immutability

Constants and Immutability

Enumerations

Complex Enumerations

Java Memory Allocation

Parameter Passing

Java Memory Cleanup

Summary

Practices for Lesson 5: Overview

Implement Inheritance and Use Records

Objectives

Extending Classes

Object Class

Reusing Parent Class Code Through Inheritance

Instantiating Classes and Accessing Objects

Rules of Reference Type Casting

Verifying Object Type Before Casting the Reference

Pattern Matching for instanceof

Reference Code Within the Current or Parent Object

Defining Subclass Constructors

Class and Object Initialization: Summary

Overriding Methods and Using Polymorphism

Reusing Parent Class Logic in Overwritten Method

Defining Abstract Classes and Methods

Defining Final Classes and Methods

Sealed Classes and Interfaces

Overriding Object Class Operations: toString

Overriding Object Class Operations: equals

Override Object Class Operations: hashCode

Comparing String Objects

Java Records

Custom Record Constructors

Record Patterns

Pattern Matching for switch

Factory Methods

Summary

Practices for Lesson 6: Overview

Interfaces and Generics

Objectives

Java Interfaces

Multiple Inheritance Problem

Implement Interfaces

Default, Private, and Static Methods in Interfaces

Interface Hierarchy

Default Methods Inheritance

Interface Is a Type

Functional Interfaces

Generics

Use Generics

Examples of Java Interfaces: java.lang.Comparable

Examples of Java Interfaces: java.util.Comparator

Examples of Java Interfaces: java.lang.Cloneable

Composition Pattern

Summary

Practices for Lesson 7: Overview

Arrays and Loops

Objectives

Arrays

Combined Declaration, Creation, and Initialization of Arrays

Multidimensional Arrays

Copying Array Content

Arrays Class

Loops

Processing Arrays by Using Loops

Complex for Loops

Embedded Loops

Break and Continue

Summary

Practices for Lesson 8: Overview

Collections

Objectives

Introduction to Java Collection API

Java Collection API Interfaces

Java Collection API Implementation Classes

Java Collection API Interfaces and Implementation Classes

Create List Object

Manage List Contents

Create Set Object

Manage Set Contents

Create Deque Object

Manage Deque Contents

Create HashMap Object

Manage HashMap Contents

Iterate Through Collections

Sequenced Collections

Other Collection Behaviors

Use java.util.Collections Class

Access Collections Concurrently

Prevent Collections Corruption

Legacy Collection Classes

Summary

Practices for Lesson 9: Overview

Nested Classes and Lambda Expressions

Objectives

Types of Nested Classes

Static Nested Classes

Member Inner Classes

Local Inner Classes

Anonymous Inner Classes

Anonymous Inner Classes and Functional Interfaces

Understand Lambda Expressions

Define Lambda Expression Parameters and Body

Use Method References

Default and Static Methods in Functional Interfaces

Use Default and Static Methods of the Comparator Interface

Use Default and Static Methods of the Predicate Interface

Summary

Practices for Lesson 10: Overview

Java Streams API

Objectives

Characteristics of Streams

Create Streams Using Stream API

Stream Pipeline Processing Operations

Using Functional Interfaces

Primitive Variants of Functional Interfaces

Bi-argument Variants of Functional Interfaces

Perform Actions with Stream Pipeline Elements

Perform Filtering of Stream Pipeline Elements

Perform Mapping of Stream Pipeline Elements

Join Streams Using flatMap Operation

Other Intermediate Stream Operations

Short-Circuit Terminal Operations

Process Stream Using count, min, max, sum, average Operations

Aggregate Stream Data using reduce Operation

General Logic of the collect Operation

Using Basic Collectors

Perform a Conversion of a Collector Result

Perform Grouping or Partitioning of the Stream Content

Mapping and Filtering with Respect to Groups or Partitions

Parallel Stream Processing

Parallel Stream Processing Guidelines

Restrictions on Parallel Stream Processing

Spliterator

Spliterator Characteristics

Summary

Practices for Lesson 11: Overview

Exception Handling, Logging, and Debugging

Objectives

Using Java Logging API

Logging Method Categories

Guarded Logging

Log Writing Handling

Logging Configuration

Describe Java Exceptions

Create Custom Exceptions

Throwing Exceptions

Catching Exceptions

Exceptions and the Execution Flow

Helpful NullPointerExceptions

Example Throwing an Unchecked Exception

Example Throwing a Checked Exception

Handling Exceptions

Resource Auto-Closure

Suppressed Exceptions

Handle Exception Cause

Java Debugger

Debugger Actions

Manipulate Program Data in Debug Mode

Validate Program Logic Using Assertions

Normal Program Flow with No Exceptions

Program Flow Producing a Runtime Exception

Program Flow Catching Specific Checked Exception

Program Flow Catching Any Exceptions

Summary

Practices for Lesson 12: Overview

Java IO API

Objectives

Java Input-Output Principals

Java Input-Output API

Reading and Writing Binary Data

Basic Binary Data Reading and Writing

Reading and Writing Character Data

Basic Character Data Reading and Writing

Connecting Streams

Standard Input and Output

Using Console

Understand Serialization

Serializable Object Graph

Object Serialization

Serialization of Sensitive Information

Customize Serialization Process

Serialization and Versioning

Working with Filesystems

Constructing Filesystem Paths

Navigating the Filesystem

Analyze Path Properties

Set Path Properties

Create Paths

Create Temporary Files and Folders

Copy and Move Paths

Delete Paths

Handle Zip Archives

Represent Zip Archive as a FileSystem

Access HTTP Resources

Summary

Practices for Lesson 13: Overview

Java Concurrency and Multithreading

Objectives

Java Concurrency Concepts

Implement Threads

Thread Life Cycle

Interrupt Thread

Block Thread

Make Thread Wait Until Notified

Common Thread Properties

Create Executor Service Objects

Manage Executor Service Life Cycle

Implementing Executor Service Tasks

Locking Problems

Writing Thread-Safe Code

Ensure Consistent Access to Shared Data

Nonblocking Atomic Actions

Ensure Exclusive Object Access Using Intrinsic Locks

Intrinsic Lock Automation

Nonblocking Concurrency Automation

Alternative Locking Mechanisms

CPU Versus IO Bound Concurrent Tasks

Virtual Threads API

Virtual Thread Operations

Summary

Practices for Lesson 14: Overview

Modules and Deployment

Objectives

Compile, Package, and Execute Nonmodular Java Applications

Nonmodular Java Characteristics

What Is a Module?

Java Modules

Java Module Categories

Define Module Dependencies

Export Module Content

Module Example

Open Module Content

Open an Entire Module

Produce and Consume Services

Services Example

Multi-Release Module Archives

Compile and Package a Module

Execute a Modularized Application

Migrating Legacy Java Applications Using Automatic module

Create Custom Runtime Image

Execute Runtime Image

Optimize a Custom Runtime Image

Check Dependencies

Summary

Practices for Lesson 15: Overview

Annotations

Objectives

Annotations: Introduction

Design Annotations

Apply Annotations

Dynamically Discover Annotations

Document the Use of Annotations

Annotations that Validate Design

Deprecated Annotation

Suppress Compiler Warnings

Varargs and Heap Pollution

Summary

Java Database Connectivity

Objectives

Java Database Connectivity (JDBC)

JDBC API Structure

Manage Database Connections

Create and Execute Basic SQL Statements

Create and Execute Prepared SQL Statements

Create and Execute Callable SQL Statements

Process Query Results

Control Transactions

Discover Metadata

Customize ResultSet

Set Up ResultSet Type

Set Up ResultSet Concurrency and Holdability

Summary

Java Security

Objectives

Security as Nonfunctional Requirement

Security Threats

Denial of Service (DoS) Attack

Define Security Policies

Changes in the Security API

Secure File System and I/O Operations

Best Practices for Protecting Your Code

Erroneous Value Guards

Protect Sensitive Data (Part 1)

Protect Sensitive Data (Part 2)

Prevent SQL Injections

Prevent JavaScript Injections

Prevent XML Injections

Discover and Document Security Issues

Summary

Advanced Generics

Objectives

Compiler Erases Information About Generics

Generic and Raw Type Compatibility

Generics and Type Hierarchy

Wildcard Generics

Upper Bound Wildcard

Lower Bound Wildcard

Collections and Generics Best Practices

Summary

Java Applications on Oracle Cloud

Objectives

Cloud Application Requirements

Cloud Application Runtime Infrastructure

Cloud Java Application Servers

Package and Deploy Cloud Application

Optimise deployment with GraalVM

HTTP Protocol Basics

REST Service Conventions and Resources

Configure and Launch REST Service Application Using Helidon SE

Summary

Miscellaneous Java Topics

Objectives

Builder Design Pattern

Singleton Design Pattern

Java Regular Expression API

Regular Expressions: Character Classes

Regular Expressions: Quantifiers

Regular Expressions: Boundaries

File IO Watch Service

Summary