Groovy Programming Training Course

Introduction to Groovy

• Getting started with Apache Groovy
• The history and evolution of the Groovy language
• The relationship between Groovy and the Java Virtual Machine
• Groovy as both a scripting and general-purpose programming language
• Typical use cases for Groovy
• Integrating Groovy into Java-based projects
• The benefits of using Groovy in conjunction with Java
• An overview of the project we will build

Overview of Groovy Features

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

Setting up the Development Environment

• Installing and configuring Groovy
• Understanding Groovy distributions
• Using Groovy via the command line
• Executing Groovy scripts
• Setting up an Integrated Development Environment (IDE)
• Creating a new Groovy project
• Managing project dependencies
• Integrating Groovy with existing Java projects
• Configuring the development environment for containerized deployments

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 and explicit typing
• String literals and interpolation
• Single-line and multiline strings
• Operators and expressions
• Groovy operators and shortcuts
• Null handling strategies
• Safe navigation
• 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
• Collection transformations
• Filtering and searching collections
• Sorting and grouping data
• Groovy collection methods

Using Groovy Closures

• Understanding closures
• Closure syntax
• Closure parameters
• Implicit closure parameters
• Calling closures
• Closures as variables
• Passing closures to methods
• Returning closures from methods
• Closures and collections
• Using closures for filtering and transformation
• Scope and variable capture
• Closures for functional programming
• Practical closure patterns

Controlling Program Flow with Groovy Control Structures

• Conditional statements
• if and else constructs
• Nested conditions
• switch statements
• Loops and iteration
• for, while, and do-while loops
• Ranges in loops
• Using closures for iteration
• break and continue
• Exception handling
• try, catch, and finally
• 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
• Creating domain models for the sample application

Runtime MetaProgramming and Compile Time MetaProgramming

• Introduction to Groovy meta-programming
• Dynamic method invocation
• Expando objects
• Runtime method and property manipulation
• Categories and extensions
• MetaClass
• Adding methods dynamically
• Intercepting method calls
• Compile-time transformations
• Common AST transformations
• Using meta-programming responsibly
• Practical meta-programming examples

Working with Builders

• Introduction to the builder pattern
• Groovy builders and their purpose
• 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

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 query results
• Inserting, updating, and deleting data
• Parameterized queries
• Transactions
• Handling database exceptions
• Working with Groovy SQL
• Building database functionality for the sample application

Calling Java from Groovy

• Groovy and Java interoperability
• Using Java classes from Groovy
• Calling Java methods
• Working with Java libraries
• Using Java collections
• Handling Java exceptions
• Groovy syntax compared with Java syntax
• Calling Groovy code from Java
• Mixing Groovy and Java source files
• Integrating Groovy into existing Java applications
• Interoperability best practices

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
• Building JSON request bodies
• Handling authentication
• Managing 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
• Working with strings
• Enhanced collections
• File and directory operations
• Reading and writing files
• Working with streams
• Processing XML
• Processing JSON
• Working with dates and times
• Utility methods and convenience APIs
• Selecting appropriate GDK functionality

Unit Testing a Groovy Application

• Introduction to testing Groovy applications
• Test-driven development concepts
• Writing unit tests
• Using testing frameworks
• Structuring test classes
• Assertions
• Testing classes and methods
• Testing closures
• Testing exceptions
• 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
• Handling compilation problems
• Troubleshooting Java interoperability issues
• Debugging closures and collection operations
• Investigating database connectivity problems
• 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