Java Training Course (Introduction to Java 21+)

Who should attend

This course is ideal for software developers who want to be able to begin to develop modern Java applications or services. Java is one of the most popular languages for both recruiters and developers and is the backbone of many applications and services whether they use the web, traditional relational or NoSQL databases or provide stand-alone functionality.

Prerequisites

Delegates will ideally have some previous programming experience in another language such as Python, JavaScript, Perl, PHP, C# or C++. No previous Object-Oriented Programming is assumed but would certainly be helpful. Please let us know if you have any questions about getting started with Java.

On-site

If you are interested in a custom on-site / in-house introduction to Java training course for any size of team, please get in touch – we would be glad to help build a course that meets your learning requirements.

We can take into account your existing technical skills, project requirements and time-frames, and specific topics of interest to tailor a workshop or wider training programme based on your learning goals.

Java Overview

• Current Release Plan and Recent History (LTS)
• How the Java Environment Works
• HelloWorld Program
• Launch Single-File Source Code
• jShell REPL
• Comments and Terminators
• Identifiers

Syntax and Types

• Java Variables
• var declarations
• Java Types
• Basic Java Types
• Reference types
• Conditional Expressions
• Logical operators
• If statement
• While Statement
• Do Statement
• For statement
• Special flow of control operators
• Switch statement
• Updated switch statement
• Numerical Operators
• Casting
• Strings and String Templates
• Printf style output

Classes and Objects

• What is an Object?
• Objects and Encapsulation
• What is a Class?
• Class Object Relationship
• The Person class
• Variable types
• Constructors
• Working with the class Person

Working with Methods

• Method Definitions
• Method Arguments & Return Types
• Overloading Methods
• Method Invocations
• Defining methods
• Constructors Versus Methods
• toString() method
• Adding behaviour to the class Person
• The PersonApp program

Class Inheritance

• Inheritance in Java
• Implementing Inheritance
• Rule for overriding methods
• Rules for Polymorphic variables
• Casting and Inheritance
• The super variable
• Constructors and Inheritance

Abstract Classes, Class Side Behaviour and Final

• Abstract Classes
• Abstract Classes in Java
• Defining an Abstract Class
• Extending an Abstract Class
• Using Concrete Subclasses
• Class Side Information
• Class Side Data
• Class Side Behaviour
• Final Keyword

Java Interfaces and Enumerations

• What is an Interface in Java?
• Basic Interface Definitions
• Implementing an Interface
• Interface
• Using an Interface in a Contract
• Inheritance by Interfaces and Types
• Classes and multiple Interfaces
• Default Interface Methods
• Static Interface Methods
• Enumeration Support
• Implementing Enumerated Types

Records

• Traditional Class Definition
• Record Version
• Record Classes
• Instantiating Record Classes
• Overriding autogenerated methods
• Static Data and Behaviour
• Other Features

Sealed Types

• Purpose of sealed classes
• Defining sealed classes
• Subclasses of sealed classes
• Constraints on sealed subclasses
• Subclasses in the same file
• Sealed interfaces
• Record classes as Subclasses

Packages

• Packages
• Class-Package Relationship
• Declaring Packages
• Packaging the Person class
• Role of the Classpath
• JAR Files
• Encapsulation and Packages
• Class modifier
• Constructor Modifier
• Variable Modifier
• Method Modifiers
• Package Summary

Java 9+ Modules

• Introduction the JPMS
• Java Platform Module System
• Why we need modules
• Look at what modules are
• How to define a module
• How to create a single module application
• How to create a multiple module application
• How to link modules

Arrays

• What is a Java Array?
• Creating arrays of Objects
• Accessing Array Elements
• Main method args array
• Short hand from
• Ragged Arrays in Java
• Working with Ragged Arrays
• Implications of Inheritance for Arrays
• Integer Array Example

Java Generics

• Generics and Basic Types
• Generics and Their Types
• Adding Generics to your classes
• A simple user defined Generic class (the Bag class)
• Type Equality
• Generic Collection Assignment
• Generics and Inheritance

Collections Classes

• Collections API
• ArrayList
• Interfaces v Concrete Classes
• HashMap
• Iteration and Enumeration
• Queues
• Generics and Collections
• For Loops
• Boxing and Unboxing
• Raw Collections

Java 9+ Immutable Collections

• Why Immutability?
• Immutability
• List.of Factory method
• Set.of Factory method
• Map.of Factory method
• Immutable Collection Nodes
• Java 10 Enhancement

Error and Exception Handling

• Errors & Exceptions
• Exception types in Java
• Part of the Exception Hierarchy
• Exception Handling
• Local Handling
• Exception Handling Example
• Passing the Buck
• Try with Resources
• Defining new Exceptions
• Chained Exceptions

Nested / Inner Classes

• Four types of Nested / Inner Class
• Properties of Member level inner classes
• Properties of Method Inner classes
• Anonymous Method Inner classes
• Java 11 Nest-based Access

Java Functions

• Functional Programming
• Functional Programming in Java
• Functional Interfaces
• Using Functional Interfaces
• Lambdas in Java
• Closing / Capturing Variables
• Returning Functions
• Combining Functions
• Higher Order Functions
• Defining Lambdas
• Method References

Java Optional Type

• Null considered Harmful
• Java Optional Type
• Optional Variables
• Creating Optional values
• Method Summary

Java 9 Streams

• Streams
• Streams from Collections
• Terminal / Non Terminal Operators
• Creating a Stream
• Map Operation
• Collectors
• Filter operation
• Sorted operation
• ForEach
• Pipelining Operations
• Parallel Streams
• Not just collections

Files, Paths and IO Streams

• Introducing NIO.2
• Paths class and Path Interface
• The Files class
• File Attributes
• The File Watcher Service
• IO Streams
• Scanners