Groovy Programming Training Course

Introduction to Groovy

• Overview of Apache Groovy
• Historical context and evolution of the language
• The relationship between Groovy and the Java Virtual Machine
• Groovy as both a scripting and a general-purpose programming language
• Typical use cases for Groovy
• Integrating Groovy into Java-based projects
• Benefits of using Groovy alongside Java
• Introduction to the sample application

Groovy Features at a Glance

• Dynamic typing with optional static typing
• Enhanced scripting capabilities
• Concise syntax and modern language enhancements
• Closures and functional programming styles
• Groovy collections and extended APIs
• Operator overloading features
• String interpolation techniques
• Safe navigation and the Elvis operator
• Developing Domain-Specific Languages (DSLs)
• Meta-programming possibilities
• The Groovy Development Kit (GDK)

Preparing the Development Environment

• Installation and configuration of Groovy
• Utilizing various Groovy distributions
• Interacting with Groovy via the command line
• Executing Groovy scripts
• Setting up an Integrated Development Environment (IDE)
• Initializing a new Groovy project
• Managing project dependencies
• Integrating Groovy components into Java projects
• Configuring the environment for containerized deployments

Developing Your First Groovy Application

• Creating a foundational Groovy script
• Analyzing the structure of Groovy scripts
• Executing Groovy applications
• Utilizing the println statement
• Manipulating variables
• Defining methods
• Incorporating comments and documentation
• Assembling a simple sample application
• Compiling Groovy source code

Navigating Groovy Syntax

• Statements and expressions in Groovy
• Semicolons and optional syntactic elements
• Handling variables and constants
• Dynamic versus explicit typing
• String literals and interpolation
• Working with single-line and multi-line strings
• Operators and complex expressions
• Groovy-specific operators and shortcuts
• Null handling strategies
• Implementing safe navigation
• Using the Elvis operator
• Multiple assignment operations

Groovy Data Types and Collections

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

Mastering Groovy Closures

• Conceptual understanding of closures
• Closure syntax and structure
• Defining closure parameters
• Handling implicit parameters
• Invoking closures
• Assigning closures to variables
• Passing closures as method arguments
• Returning closures from methods
• Utilizing closures with collections
• Applying closures for filtering and transformation
• Scope rules and variable capture
• Functional programming with closures
• Common practical closure patterns

Program Flow Control in Groovy

• Conditional logic
• Using if and else blocks
• Nested conditional statements
• switch statement implementation
• Loops and iteration mechanisms
• for, while, and do-while loops
• Using ranges within loops
• Closures as iteration tools
• Control flow with break and continue
• Exception handling strategies
• try, catch, and finally blocks
• Raising custom exceptions
• Unique Groovy control-flow features

Object-Oriented Programming (OOP) in Groovy

• Declaring Groovy classes
• Properties and fields
• Constructors
• Methods
• Encapsulation principles
• Inheritance mechanisms
• Interfaces
• Abstract classes
• Polymorphism
• Method overriding
• Method overloading
• Automated getters and setters
• Traits
• Enums
• Designing domain models for the sample application

Runtime and Compile-Time Meta-Programming

• Foundations of Groovy meta-programming
• Dynamic method dispatch
• Expando objects
• Manipulating methods and properties at runtime
• Categories and class extensions
• The MetaClass mechanism
• Dynamically injecting methods
• Intercepting method invocations
• Compile-time transformations
• Standard Abstract Syntax Tree (AST) transformations
• Responsible meta-programming practices
• Practical meta-programming scenarios

Utilizing Builders

• The builder pattern concept
• Purpose and usage of Groovy builders
• Constructing hierarchical structures
• XML builders
• JSON builders
• Generating HTML and markup
• Configuring builder outputs
• Combining closures with builders
• Developing custom builders
• Leveraging builders in Domain-Specific Languages

Database Interaction with Groovy

• Core database connectivity concepts
• Establishing connections between Groovy apps and databases
• JDBC and Groovy database APIs
• Setting up database connections
• Executing SQL queries
• Retrieving and reading query results
• Performing insert, update, and delete operations
• Using parameterized queries
• Managing transactions
• Handling database-related exceptions
• Working with Groovy SQL modules
• Implementing database features in the sample application

Calling Java from Groovy

• Groovy-Java interoperability
• Utilizing Java classes within Groovy
• Invoking Java methods
• Integrating with Java libraries
• Using Java collections in Groovy
• Catching and handling Java exceptions
• Comparing Groovy and Java syntax
• Calling Groovy code from Java
• Combining Groovy and Java source files
• Integrating Groovy into existing Java applications
• Best practices for interoperability

Connecting to REST Services

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

Working with the GDK

• Introduction to the Groovy Development Kit (GDK)
• Enhanced Java API access
• Advanced string manipulation
• Extended collection features
• File and directory management
• File reading and writing
• Stream processing
• XML processing
• JSON processing
• Date and time utilities
• Utility methods and convenience APIs
• Selecting appropriate GDK tools

Unit Testing Groovy Applications

• Foundations of testing Groovy applications
• Test-driven development (TDD) concepts
• Writing unit tests
• Utilizing testing frameworks
• Structuring test classes
• Writing assertions
• Testing classes and methods
• Testing closures
• Verifying exception handling
• Mocking dependencies
• Data-driven testing approaches
• Testing database interactions
• Testing REST integrations
• Executing and interpreting test results

Troubleshooting

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

Summary and Conclusion

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