Groovy Programming Training Course

Introduction to Groovy

• Overview of Apache Groovy
• Historical background and evolution of Groovy
• The relationship between Groovy and the Java Virtual Machine
• Groovy as a scripting and full-fledged programming language
• Common use cases for Groovy
• Incorporating Groovy into Java-based projects
• Benefits of using Groovy in conjunction with Java
• Overview of the sample application to be built

Overview of Groovy Features

• Dynamic typing and optional static typing
• Groovy's scripting capabilities
• Concise syntax and language enhancements
• Closures and functional programming paradigms
• Groovy collections and enhanced APIs
• Operator overloading techniques
• String interpolation
• Safe navigation and the Elvis operator
• Developing Domain-Specific Languages
• Meta-programming capabilities
• The Groovy Development Kit (GDK)

Setting up the Development Environment

• Installation and configuration of Groovy
• Managing Groovy distributions
• Executing Groovy commands from the command line
• Running Groovy scripts
• Setting up an Integrated Development Environment (IDE)
• Initializing a new Groovy project
• Managing project dependencies
• Integrating Groovy with existing Java projects
• Configuring the development environment for containerized setups

Writing Your First Groovy Application

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

Getting Familiar with Groovy's Syntax

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

Using Groovy's Data Types and Collections

• Primitive and object types
• Numbers and numeric operations
• Strings and characters
• Booleans
• Dates and time-related values
• Lists
• Maps
• Sets
• Ranges
• Iterating over collections
• Transforming collections
• Filtering and searching within collections
• Sorting and grouping data
• Groovy-specific collection methods

Using Groovy Closures

• Concepts behind closures
• Closure syntax
• Defining closure parameters
• Implicit closure parameters
• Invoking closures
• Storing closures in variables
• Passing closures as method arguments
• Returning closures from methods
• Using closures with collections
• Applying closures for filtering and transformation
• Scope and variable capture
• Functional programming with closures
• Practical closure patterns

Controlling Program Flow with Groovy Control Structures

• Conditional statements
• if and else logic
• Nested conditions
• switch statements
• Loops and iteration techniques
• for, while, and do-while loops
• Using ranges in loops
• Iterating using closures
• break and continue statements
• Exception handling mechanisms
• 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 principles
• Inheritance
• Interfaces
• Abstract classes
• Polymorphism
• Method overriding
• Method overloading
• Groovy getters and setters
• Traits
• Enums
• Creating domain models for the sample application

Runtime MetaProgramming and Compile Time MetaProgramming

• Introduction to Groovy meta-programming
• Dynamic method invocation
• Expando objects
• Runtime manipulation of methods and properties
• Categories and extensions
• The MetaClass concept
• Adding methods dynamically
• Intercepting method calls
• Compile-time transformations
• Common Abstract Syntax Tree (AST) transformations
• Responsible use of meta-programming
• Practical examples of meta-programming

Working with Builders

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

Accessing a Database with Groovy

• Database connectivity concepts
• Connecting Groovy applications to databases
• JDBC and Groovy database APIs
• Configuring database connections
• Executing SQL queries
• Reading and processing query results
• Inserting, updating, and deleting data
• Using parameterized queries
• Managing transactions
• Handling database exceptions
• Working with Groovy SQL
• Implementing database functionality for the sample application

Calling Java from Groovy

• Interoperability between Groovy and Java
• Utilizing Java classes within Groovy
• Invoking Java methods
• Working with Java libraries
• Handling Java collections
• Managing Java exceptions
• Comparing 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
• Working with request parameters and headers
• Processing JSON responses
• Constructing JSON request bodies
• Managing authentication
• Handling HTTP errors
• Consuming external REST services
• Integrating REST functionality into the sample application

Working with the GDK

• Introduction to the Groovy Development Kit (GDK)
• Enhanced Java APIs
• Advanced string operations
• Enhanced collection handling
• File and directory operations
• Reading and writing files
• Working with streams
• Processing XML data
• Processing JSON data
• Handling dates and times
• Utility methods and convenience APIs
• Selecting the appropriate GDK functionality

Unit Testing a Groovy Application

• Introduction to testing Groovy applications
• Test-driven development (TDD) concepts
• Writing unit tests
• Utilizing testing frameworks
• Structuring test classes
• Using assertions
• Testing classes and methods
• Testing closures
• Testing exception handling
• Mocking dependencies
• Data-driven testing techniques
• Testing database-related functionality
• 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
• Recap of syntax, data types, and collections
• Recap of closures and functional programming
• Recap of object-oriented programming concepts
• Recap of meta-programming and builders
• Recap of database and REST integration
• Recap of Groovy and Java interoperability
• Recap of GDK capabilities
• Recap of testing practices
• Best practices for developing Groovy applications
• Final hands-on exercise
• Questions and discussion