Groovy Programming Training Course

Introduction to Groovy

• Overview of Apache Groovy
• Background and evolution of the language
• The relationship between Groovy and the Java Virtual Machine
• Using Groovy for scripting and application development
• Typical use cases for Groovy
• Integrating Groovy into Java-centric projects
• Benefits of using Groovy in conjunction with Java
• Introduction to the sample project

Overview of Groovy Features

• Dynamic typing and optional static typing
• Scripting capabilities
• Concise syntax and language extensions
• Closures and functional programming paradigms
• Enhanced collections and APIs
• Operator overloading
• String interpolation
• Safe navigation and the Elvis operator
• Building Domain-Specific Languages
• Meta-programming features
• The Groovy Development Kit (GDK)

Setting up the Development Environment

• Installation and configuration of Groovy
• Understanding different Groovy distributions
• Using the Groovy command-line interface
• Executing Groovy scripts
• Configuring an Integrated Development Environment (IDE)
• Initialising a new Groovy project
• Managing project dependencies
• Integrating Groovy with existing Java projects
• Configuring the environment for containerised development

Writing Your First Groovy Application

• Creating a basic script
• Understanding script structure
• Running Groovy applications
• Utilising the println statement
• Working with variables
• Defining methods
• Adding comments and documentation
• Developing a simple sample application
• Compiling Groovy code

Getting Familiar with Groovy's Syntax

• Statements and expressions in Groovy
• Semicolons and optional syntax rules
• Variables and constants
• Dynamic versus explicit typing
• String literals and interpolation
• Single-line and multi-line strings
• Operators and expression evaluation
• Groovy-specific operators and shortcuts
• Null value handling
• Safe navigation operators
• The Elvis operator
• Multiple assignment

Using Groovy's Data Types and Collections

• Primitive and object types
• Numeric types and operations
• Strings and character handling
• Boolean values
• Date and time management
• Lists
• Maps
• Sets
• Ranges
• Iterating through collections
• Transforming collections
• Filtering and searching data
• Sorting and grouping information
• Groovy collection methods

Using Groovy Closures

• Concepts behind closures
• Closure syntax
• Defining parameters
• Implicit parameters
• Invoking closures
• Storing closures in variables
• Passing closures as arguments
• Returning closures from methods
• Working with collections and closures
• Filtering and transforming data using closures
• Scope and variable capture
• Functional programming with closures
• Practical closure patterns

Controlling Program Flow with Groovy Control Structures

• Conditional logic
• if and else statements
• Nested conditional statements
• switch statements
• Loops and iteration
• for, while, and do-while loops
• Using ranges in loops
• Iterating with closures
• break and continue statements
• Exception handling
• try, catch, and finally blocks
• Raising custom exceptions
• Groovy-specific control flow features

Implementing Object Oriented Programming (OOP) in Your Application

• Defining classes in Groovy
• Properties and fields
• Constructors
• Methods
• Encapsulation principles
• Inheritance
• Interfaces
• Abstract classes
• Polymorphism
• Method overriding
• Method overloading
• Getters and setters
• Traits
• Enums
• Building domain models for the sample application

Runtime MetaProgramming and Compile Time MetaProgramming

• Introduction to Groovy meta-programming
• Dynamic method invocation
• Expando objects
• Modifying methods and properties at runtime
• Categories and extensions
• The MetaClass
• Adding methods dynamically
• Intercepting method calls
• Compile-time transformations
• Common AST transformations
• Responsible use of meta-programming
• Practical examples of meta-programming

Working with Builders

• The builder pattern
• Purpose of Groovy builders
• Creating hierarchical structures
• XML builders
• JSON builders
• Generating HTML and markup
• Configuring builder output
• Using closures within builders
• Creating custom builders
• Applying builders in Domain-Specific Languages

Accessing a Database with Groovy

• Concepts of database connectivity
• Connecting Groovy applications to databases
• JDBC and Groovy database APIs
• Configuring connections
• Executing SQL queries
• Reading results
• Insert, update, and delete operations
• Parameterized queries
• Transactions
• Handling database exceptions
• Using the Groovy SQL module
• Implementing database features in the sample application

Calling Java from Groovy

• Interoperability between Groovy and Java
• Accessing Java classes
• Invoking Java methods
• Utilising Java libraries
• Handling Java collections
• Catching Java exceptions
• Comparing Groovy and Java syntax
• Calling Groovy from Java
• Combining Groovy and Java source files
• Integrating Groovy into existing Java applications
• Best practices for interoperability

Connecting to REST Services and Applications

• Introduction to REST APIs
• HTTP concepts for Groovy applications
• Sending HTTP requests
• Managing GET, POST, PUT, and DELETE operations
• Handling parameters and headers
• Parsing JSON responses
• Constructing JSON request bodies
• Authentication mechanisms
• Handling HTTP errors
• Consuming external services
• Integrating REST functionality into the sample application

Working with the GDK

• Introduction to the Groovy Development Kit
• Enhanced Java APIs
• String manipulation
• Enhanced collection utilities
• File and directory operations
• Reading and writing files
• Stream processing
• XML processing
• JSON processing
• Date and time utilities
• Convenience methods and APIs
• Selecting appropriate GDK features

Unit Testing a Groovy Application

• Introduction to testing Groovy applications
• Test-driven development concepts
• Writing unit tests
• Using testing frameworks
• Structuring test classes
• Assertions
• Testing classes and methods
• Testing closures
• Testing exception handling
• Mocking dependencies
• Data-driven testing
• Testing database interactions
• Testing REST integrations
• Executing and analysing test results

Troubleshooting

• Diagnosing syntax errors
• Debugging runtime errors
• Resolving compilation issues
• Addressing interoperability problems
• Debugging closures and collections
• Investigating database connectivity issues
• Troubleshooting REST API integrations
• Debugging meta-programming behaviour
• Using logging and diagnostic tools
• Practical troubleshooting exercises

Summary and Conclusion

• Review of language fundamentals
• Recap of syntax, types, and collections
• Recap of closures and functional programming
• Recap of object-oriented programming
• Recap of meta-programming and builders
• Recap of database and REST integration
• Recap of interoperability with Java
• Recap of GDK capabilities
• Recap of testing practices
• Best practices for Groovy development
• Final hands-on exercise
• Questions and discussion