Groovy Programming Training Course

Introduction to Groovy

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

Overview of Groovy Features

• Dynamic typing and optional static typing
• Scripting capabilities of Groovy
• Concise syntax and language enhancements
• Closures and functional programming paradigms
• Groovy collections and improved APIs
• Operator overloading
• String interpolation
• Safe navigation and Elvis operators
• Developing Domain-Specific Languages
• Meta-programming capabilities
• Groovy Development Kit (GDK)

Setting up the Development Environment

• Installation and configuration of Groovy
• Managing Groovy distributions
• Executing Groovy from 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 development environment for containerized applications

Writing Your First Groovy Application

• Creating a basic Groovy script
• Understanding the structure of Groovy scripts
• Executing Groovy applications
• Using the println statement
• Managing 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 versus explicit typing
• String literals and interpolation
• Single-line and multiline string handling
• Operators and complex expressions
• Groovy-specific operators and shortcuts
• Null value handling
• Safe navigation operators
• The Elvis operator
• Multiple assignment techniques

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 collection data
• 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
• Using closures as variables
• Passing closures to methods
• Returning closures from methods
• Interaction between closures and collections
• Utilizing closures for filtering and transformation
• Scope rules and variable capture
• Functional programming with closures
• Common closure patterns

Controlling Program Flow with Groovy Control Structures

• Conditional statements
• if and else structures
• Nested conditional logic
• switch statements
• Loops and iteration mechanisms
• for, while, and do-while loops
• Using ranges in loops
• Iterating with 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 mechanism
• Dynamically adding methods
• Intercepting method calls
• Compile-time transformations
• Common AST transformations
• Responsible use of meta-programming
• Practical examples of meta-programming

Working with Builders

• Introduction to the builder pattern
• Purpose and use of Groovy builders
• Constructing hierarchical structures
• Building XML
• Building JSON
• Generating HTML and markup
• Configuring builder output
• Utilizing closures within builders
• Creating custom builder implementations
• 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 and processing query results
• Performing Insert, Update, and Delete operations
• Using parameterized queries
• Managing transactions
• Handling database exceptions
• Working with Groovy SQL
• Implementing database functionality in the sample application

Calling Java from Groovy

• Groovy and Java interoperability
• Utilizing Java classes within Groovy
• Invoking Java methods
• Working with Java libraries
• Using Java collections in Groovy
• 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 relevant to Groovy applications
• Sending HTTP requests
• Handling GET, POST, PUT, and DELETE operations
• Managing request parameters and headers
• Processing 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
• Enhanced Java APIs
• String manipulation
• Enhanced collection features
• File and directory operations
• Reading and writing files
• Working with streams
• Processing XML
• Processing JSON
• Handling dates and times
• Utility methods and convenience APIs
• Selecting appropriate GDK features

Unit Testing a Groovy Application

• Introduction to testing Groovy applications
• Test-driven development principles
• 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 approaches
• 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
• Review of syntax, 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 and Java interoperability
• Review of GDK capabilities
• Review of testing practices
• Best practices for developing Groovy applications
• Final hands-on exercise
• Questions and discussion