Introduction to Java 21 Using Eclipse

Materials

All Java training students receive comprehensive courseware.

Software Needed on Each Student PC

• A recent version of Windows, macOS, or Linux with at least 8 GB RAM
• JDK 21 or later
• Eclipse or IntelliJ IDEA
• Other free software - please contact us if you have purchased this class

Overview of Java

• History Of Java
• Java Release Cycle
• Benefits Of Java
• What Is Java?
• What's This "Virtual Machine"?
• Comparison to Other Languages
• Java Programs
• Basic Java Development Tools
• Java Editions
• Example – HelloWorld
• Java Classes
• Main Methods
• Statements

Java Tools in Eclipse

• Eclipse Platform
• Eclipse Workspace
• Perspectives, Views & Editors
• Basic Operations with Eclipse Views and Perspectives
• The Java Perspective
• The Debug Perspective
• Navigator View
• Package Explorer
• Outline View
• Problems View
• Eclipse Preferences
• Build and Validation
• Code Completion, Templates and Snippets
• Searching
• Configure Compiler Class Path
• JRE Switching

Basic Object Concepts

• What Is An Object?
• State
• Behavior
• Encapsulation
• Encapsulation Examples
• Classes vs. Objects
• Inheritance
• Interfaces
• Polymorphism
• Benefits Of Objects

Basic Java Syntax

• Declaring And Initializing Variables
• Keywords
• Coding Tips – Variables
• Primitive Data Types
• Logical - boolean
• Textual - char and String
• Integral - byte, short, int, long
• Floating Point - float and double
• Numeric Literals
• Strings
• Creating Strings
• White Space
• Comments
• Coding Tips - Comments
• Java Statements
• Coding Tips - Statements
• Scope of a Variable
• Local Variable Type Inference
• System.out/System.in
• Scanner Class

Operations and Making Decisions

• Operator Categories
• Special Situations
• Binary Operators
• Integer Division
• Numeric Promotion
• Type Conversion Of Primitive Types
• Unary Operators
• Relational Operators
• Logical Operators
• "Short Circuited" Operators
• Bitwise Operators
• Shift Operators
• Overflow And Underflow
• Assignment Operators
• Ternary Operator
• Calculation Errors
• Operator Precedence
• Precedence Examples
• Combining Strings
• Coding Tips - Operators
• Control Flow Statements
• 'if' Statement
• 'if…else' Statement
• Nested Statements
• Coding Tips - if & if-else

Using Classes and Objects

• Objects, Instances, And Classes
• What Are Classes?
• Working With Classes And Objects
• Instantiation
• Instance Methods
• Object References
• Null Values
• String Operations
• "Wrapper" Classes
• Autoboxing

Writing Classes

• Why Define Your Own Classes?
• Encapsulation
• Elements Of A Class
• Defining Classes
• Coding Tips - Class Definitions
• Fields
• Defining Fields
• Coding Tips - Fields
• Methods
• Defining Methods
• Passing Parameters
• Overloading Methods
• Coding Tips - Methods
• Local Variables vs. Instance Variables
• Example - Defining a Class
• Example - Fields
• Example - Defining a Method
• Example - Calling a Method

Controlling Code Access and Code Organization

• Controlling Access
• Data Hiding
• Encapsulation
• JavaBeans
• Packages
• Naming Packages
• Declaring Packages In Classes
• Problems Solved With Packages
• Package Access
• Example - Access Modifiers
• Import Statement
• Using Classes From Packages
• Coding Tips - Import Statements
• Correlation To File Structure
• Class Path
• Java Core Packages
• Java Module System
• Java API Documentation

Constructors and Class Members

Constructors

• Default Constructor
• Multiple Constructors
• Defining Constructors
• Example - Calling Constructors
• "Good" Constructors
• 'this' Keyword
• Using 'this' to Call a Constructor
• Using 'this' to Set a Field

Class Members

• Examples Of Class Members
• Comparison With Instance Members
• Use Of Class Variables
• Static Class Methods
• Use Of Class Methods
• The Math Class
• Main Method And Command Line Arguments
• Declaring Constants
• Coding Tips - Class Members
• Useful Standard Class Members

Java Records

• Java Records
• Records vs. Classes
• Records - Example Definitions
• Records - Example Usage
• Auto-generated Elements in Records
• Overriding Auto-Generated Methods
• Overriding the Implicit Constructor
• When to use Java Records
• When NOT to use Java Records
• Additional Facts about Records

Advanced Control Structures

• 'switch' Statement
• Switch Features
• Example: Switch on int expression
• Example: Switch on String expression
• Example: Switch on Object type
• Example: Switch on Object Attributes
• Example: Switch on RegEx Match
• Switch "Fall Through"
• 'for' Loop
• 'while' Loop
• 'do…while' Loop
• Break Statement
• Labeled Statements
• Continue Statement
• Example - continue
• Example - Labeled continue
• Coding Tips - Control Structures

Inheritance

• Inheritance Is…
• Inheritance Examples
• Declaring Inheritance
• Inheritance Hierarchy
• Access Modifiers Revisited
• Inherited Members
• Instances Of A Subclass
• Example Of Inheritance
• Role In Reuse
• Overriding Methods
• @Override Annotation
• The super Keyword
• Problems with Constructors
• Limiting Subclasses
• Calling Methods in Constructors
• The Object Class

Sealed Classes

• What are Sealed Classes?
• The Benefits of Sealed Classes
• Features of Sealed Classes
• Sealed Class Rules
• Sealed Class Syntax
• Sealed Interfaces
• Use Cases for Sealed Classes

Arrays

• Declaring Arrays
• Populating Arrays
• Accessing Arrays
• Arrays of Objects
• Array Length
• Coding Tips - Arrays
• Array References
• Multidimensional Arrays
• Arrays Of Arrays
• Copying Arrays
• For-Each loop
• Command Line Arguments
• Variable Arguments

Commonly Overridden Methods

• Overriding Methods
• Using Eclipse to Override Methods
• toString()
• toString() in Object
• Overriding toString()
• Comparing Objects
• Using == vs. equals(..)
• Overriding equals(..)
• Complex Comparisons
• equals(..) Example
• hashCode()
• Overriding hashCode()
• hashCode() Example
• Generating equals and hashCode

Exceptions

• What is an Exception?
• Benefits
• The java.lang.Exception Class
• How to Work With Exceptions
• Example Exception Handling
• The try-catch-finally Statement
• Flow of Program Control
• Exception Hierarchy
• Checked Exceptions
• Unchecked Exceptions
• Coding Tips - Exception Types
• Catching Subclass Exceptions
• Catching Multiple Exceptions
• Specifying Thrown Exceptions
• Rethrowing Exceptions
• Chaining Exceptions
• Creating your own Exception
• try-with-resources Statement
• Suppressed Exceptions in try-with-resources

Interfaces and Polymorphism

• Casting Objects
• The instanceof Operator
• Abstract Classes
• Abstract Class – An Example
• Interface
• Comparable Interface
• Default Methods
• Static Methods
• Private Interface Methods
• Coding Tips - Superclass or Abstract Class/Interface?
• Coding Tips – Abstract Class or Interface
• Polymorphism
• Conditions for Polymorphism
• Coding Tips - Leveraging Polymorphism
• Covariant Return Types
• Covariant Return Types – An Example
• Summary

Useful Java Classes

• Java Logging API
• Control Flow of Logging
• Logging Levels
• Loggers
• Logging Example
• Logging Handlers
• Logging Formatters & Log Manager
• Logging Configuration File
• Example Logging Configuration File
• Logging Filters
• java.lang.StringBuilder
• java.util.StringTokenizer
• java.util.Arrays & java.util.Collections
• java.util.Random
• Java Date and Time
• Local Date and Time
• java.util.Date and java.time.Instant
• Formatting
• Formatting Example

Collections and Generics

• What are Collections?
• Arrays vs. Collections
• Main Collections Interfaces
• java.util.Collection
• Main Collection Methods
• Sets
• java.util.List
• java.util.Queue
• Iteration on a Collection
• Iterator vs. For-Each Loop
• Maps
• java.util.Map
• Other Maps
• Collections Implementations
• Abstract Implementations
• Choosing a Collection Type
• Generics
• Generics and Collections
• Generic Collection Example
• Generic Collection Example
• Collections and Primitive Types
• Generic Diamond Operator
• Collection Factory Methods

Introduction to Lambda Expressions

• Functional Interface
• Anonymous Inner Class (AIC)
• Downside of AIC
• Lambda Expressions
• Lambda Expression Syntax
• Method Reference
• Benefits of Lambda Expressions – An Example
• Initial Version
• Refactor Criteria Into Method
• Predicate Interface
• Using a Predicate
• Implement as Separate Class
• Implement as AIC
• Use Lambda Expressions
• Reuse Lambda Expressions

Input and Output

• Overview of Java Input/Output
• The File Class
• File Example
• The java.nio.file.Path Interface
• Serialization
• Serializing Object State
• Avoiding Serialization Problems
• serialVersionUID
• Options for File Input/Output
• Streams
• Input Stream
• Output Stream
• "Chained" Streams
• RandomAccessFile
• try-with-resources Statement
• Using Streams - Write Example
• Using Streams - Read Example
• Reader and Writer
• Using Readers and Writers - Write Example
• Using Readers and Writers - Read Example
• Using Readers and Writers - Scanner Read Example
• NIO Channels and Buffers

Other Java Concepts

• Annotations
• Enumerated Types
• Assertions
• When to use Assertions
• Assertions Examples
• Enabling Assertions
• JVM Storage Areas
• Java Heap Space
• Heap Size Limits
• Garbage Collection Basics
• Allocation Failure (AF)
• OutOfMemoryError
• Memory Leak
• JShell
• Distributing Java Code with JARs

Appendix A - Overview of Java SE APIs

• Java GUI Programming
• Networking
• Security
• Date and Time API
• Databases - JDBC
• Concurrent Programming
• Collections “Stream API”
• Functional Interfaces for Lambda Expressions
• Naming - JNDI
• Management - JMX
• XML
• Remote Method Invocation
• Image I/O
• Printing

Appendix B - Overview of Java EE

• Goals of Enterprise Applications
• What is Java EE?
• The Java EE Specifications
• Versions
• Role of Application Server
• Java EE Components
• What is a Servlet?
• Servlet Execution
• What is a JSP?
• JSP Code Sample
• Introduction to JSF
• Example JSF Page
• What is an EJB?
• EJB Types
• Java Persistence API
• EJB Examples
• Java Web Services
• Contexts and Dependency Injection for Java EE (CDI)
• Web Browser
• Java EE Application Structure
• EAR File
• What are Modules?

Appendix C - Advanced Java Tools

• Refactoring
• Renaming Elements
• Moving a Class to a Different Package
• Extracting Code to a Method
• Other Source Code Refactoring
• Refactoring to Improve Type Hierarchy
• Generalizing a Variable
• Pull-up and Push-down

Conclusion