Groovy Programming Training Course

Introduction to Groovy

• Getting started with Apache Groovy
• The history and evolution of the Groovy language
• Groovy’s relationship with the Java Virtual Machine
• Groovy as both a scripting and programming language
• Common scenarios for using Groovy
• Integrating Groovy into Java-based projects
• The benefits of using Groovy alongside Java
• An overview of the course sample application

Overview of Groovy Features

• Dynamic typing and the option for static typing
• Groovy’s scripting capabilities
• Concise syntax and language improvements
• Closures and functional programming concepts
• Groovy collections and extended APIs
• Operator overloading techniques
• String interpolation features
• Safe navigation and the Elvis operator
• Developing Domain-Specific Languages (DSLs)
• Meta-programming capabilities
• The Groovy Development Kit (GDK)

Setting up the Development Environment

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

Writing Your First Groovy Application

• Creating a basic Groovy script
• Understanding the structure of Groovy scripts
• Executing 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 and explicit typing
• String literals and interpolation
• Single-line and multi-line strings
• Operators and expressions
• Groovy operators and shortcuts
• Handling null values
• Safe navigation operator
• The Elvis operator
• Multiple assignment operations

Using Groovy's Data Types and Collections

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

Using Groovy Closures

• Understanding the concept of closures
• Closure syntax
• Closure parameters
• Implicit closure parameters
• Invoking closures
• Using closures as variables
• Passing closures as method arguments
• Returning closures from methods
• Closures and their relationship with collections
• Using closures for filtering and data transformation
• Scope rules and variable capture
• Closures for functional programming
• Practical patterns using closures

Controlling Program Flow with Groovy Control Structures

• Conditional statements
• if and else constructs
• Nested conditional logic
• switch statements
• Loops and iteration mechanisms
• for, while, and do-while loops
• Using ranges within loops
• Utilizing closures for iteration
• break and continue statements
• Exception handling strategies
• 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 and Compile-Time Meta-Programming

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

Working with Builders

• Introduction to the builder pattern
• Groovy builders and their purpose
• Creating hierarchical structures
• Building XML structures
• Generating JSON structures
• 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 database connections
• Executing SQL queries
• Reading query results
• Performing inserts, updates, and deletions
• Using parameterized queries
• Managing transactions
• Handling database exceptions
• Working with Groovy SQL
• Building database functionality for the sample application

Calling Java from Groovy

• Interoperability between Groovy and Java
• Utilizing Java classes in Groovy
• Calling Java methods
• Working with Java libraries
• Using Java collections
• Handling 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
• Enhanced Java APIs
• String manipulation
• Enhanced collection operations
• File and directory management
• 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 tools

Unit Testing a Groovy Application

• Introduction to testing Groovy applications
• Concepts of test-driven development
• Writing unit tests
• Using testing frameworks
• Structuring test classes
• Writing assertions
• Testing classes and methods
• Testing closures
• Testing exception handling
• Mocking dependencies
• Data-driven testing
• 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
• Utilizing logging and diagnostic tools
• Practical troubleshooting exercises

Summary and Conclusion

• Review of Groovy language fundamentals
• Recap of syntax, data 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 and Java interoperability
• Review of GDK capabilities
• Review of testing practices
• Best practices for Groovy application development
• Final hands-on exercise
• Q&A and discussion