Groovy Programming Training Course

Introduction to Groovy

• Overview of Apache Groovy
• The historical background and development of Groovy
• Relationship between Groovy and the Java Virtual Machine
• Groovy as both a scripting and general-purpose language
• Typical scenarios for using Groovy
• Utilizing Groovy within Java-centric projects
• Benefits of leveraging Groovy in conjunction with Java
• Introduction to the course sample application

Groovy Features Overview

• Dynamic typing and the option for static typing
• Scripting features in Groovy
• Simplified syntax and language enhancements
• Use of closures and functional programming paradigms
• Groovy collections and improved API interfaces
• Operator overloading capabilities
• String interpolation techniques
• Safe navigation and the Elvis operator
• Creation of Domain-Specific Languages (DSL)
• Meta-programming features
• The Groovy Development Kit (GDK)

Configuring the Development Environment

• Installation and configuration of Groovy
• Utilizing various Groovy distributions
• Executing Groovy via the command line
• Running Groovy scripts
• Setup of an Integrated Development Environment (IDE)
• Initialization of a Groovy project
• Dependency management
• Integrating Groovy into existing Java projects
• Container-specific development environment setup

Developing Your First Groovy Application

• Creating a fundamental Groovy script
• Understanding the structure of Groovy scripts
• Execution of Groovy applications
• Use of the println statement
• Managing variables
• Defining methods
• Incorporating comments and documentation
• Construction of a basic sample application
• Compilation of Groovy code

Familiarizing Yourself with Groovy Syntax

• Groovy statements and expressions
• Semicolons and optional syntactic elements
• Variables and constants
• Dynamic versus explicit typing
• String literals and interpolation
• Single-line and multi-line strings
• Operators and expressions
• Groovy-specific operators and shortcuts
• Null value handling
• Safe navigation techniques
• The Elvis operator
• Multiple assignment

Utilizing Groovy Data Types and Collections

• Primitive and object-oriented types
• Number types and arithmetic operations
• Strings and character handling
• Boolean values
• Date and time-related data types
• Lists
• Maps
• Sets
• Ranges
• Iterating through collections
• Transforming collections
• Filtering and searching within collections
• Sorting and grouping data
• Groovy collection methods

Working with Groovy Closures

• Concepts behind closures
• Closure syntax
• Defining closure parameters
• Implicit closure parameters
• Invoking closures
• Assigning closures to variables
• Passing closures as method arguments
• Returning closures from methods
• Integration of closures with collections
• Using closures for filtering and transformation tasks
• Scope and variable capture
• Functional programming with closures
• Common practical patterns for closures

Managing Program Flow with Groovy Control Structures

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

Implementing Object-Oriented Programming (OOP) in Your Application

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

Runtime and Compile-Time Meta-Programming

• Introduction to Groovy meta-programming
• Dynamic method invocation
• Expando objects
• Manipulating methods and properties at runtime
• Categories and extensions
• MetaClass
• Dynamically adding methods
• Intercepting method calls
• Compile-time transformations
• Common AST transformations
• Best practices for responsible meta-programming
• Practical examples of meta-programming

Working with Builders

• Introduction to the builder pattern
• Purpose and use of Groovy builders
• Creating hierarchical structures
• XML builders
• JSON builders
• HTML and markup generation
• Configuring builder output
• Using closures with builders
• Creating custom builders
• Applying builders in Domain-Specific Languages

Database Access with Groovy

• Concepts of database connectivity
• Connecting Groovy applications to databases
• JDBC and Groovy database APIs
• Configuring database connections
• Executing SQL queries
• Retrieving query results
• Inserting, updating, and deleting data
• Parameterized queries
• Transactions
• Handling database exceptions
• Working with Groovy SQL
• Implementing database features for the sample application

Calling Java from Groovy

• Groovy-Java interoperability
• Using Java classes within Groovy
• Invoking Java methods
• Utilizing Java libraries
• Working with Java collections
• Handling Java exceptions
• Comparison of Groovy and Java syntax
• Calling Groovy code from Java
• Mixing 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
• Handling GET, POST, PUT, and DELETE operations
• Managing request parameters and headers
• Processing JSON responses
• Constructing JSON request bodies
• Authentication handling
• Managing HTTP errors
• Consuming external REST services
• Integrating REST features into the sample application

Working with the GDK

• Introduction to the Groovy Development Kit
• Enhanced Java APIs
• String manipulation
• Enhanced collections
• File and directory operations
• Reading and writing files
• Working with streams
• XML processing
• JSON processing
• Date and time utilities
• Utility methods and convenience APIs
• Selecting appropriate GDK functionalities

Unit Testing a Groovy Application

• Introduction to testing Groovy applications
• Test-driven development (TDD) concepts
• Writing unit tests
• Utilizing testing frameworks
• Structuring test classes
• Assertions
• Testing classes and methods
• Testing closures
• Testing exception handling
• Mocking dependencies
• Data-driven testing
• Testing database-related features
• Testing REST integrations
• Running and analyzing test results

Troubleshooting

• Diagnosing Groovy syntax errors
• Debugging runtime errors
• Resolving compilation issues
• Troubleshooting Java interoperability problems
• Debugging closures and collection operations
• Investigating database connectivity issues
• Troubleshooting REST API integrations
• Debugging meta-programming behavior
• Using logging and diagnostic tools
• Practical troubleshooting exercises

Summary and Conclusion

• Review of Groovy language fundamentals
• Review of syntax, data types, and collections
• Review of closures and functional programming
• Review of object-oriented programming
• Review of meta-programming and builders
• Review of database and REST integration
• Review of Groovy-Java interoperability
• Review of GDK capabilities
• Review of testing practices
• Best practices for developing Groovy applications
• Final hands-on exercise
• Q&A and discussion