Groovy Programming Training Course

Introduction to Groovy

• Overview of Apache Groovy
• The history and evolution of the language
• Relationship between Groovy and the Java Virtual Machine
• Groovy as both a scripting and general-purpose programming language
• Common use cases for Groovy
• Integrating Groovy into Java-based projects
• Benefits of using Groovy alongside Java
• Preview of the sample application to be built

Overview of Groovy Features

• Dynamic typing and optional static typing
• Scripting capabilities in Groovy
• Concise syntax and language enhancements
• Closures and functional programming concepts
• Enhanced collections and APIs
• Operator overloading
• String interpolation techniques
• Safe navigation and the Elvis operator
• Developing Domain-Specific Languages
• Meta-programming capabilities
• Introduction to the Groovy Development Kit (GDK)

Setting up the Development Environment

• Installing and configuring Groovy
• Working with different Groovy distributions
• Executing Groovy from the command line
• Running Groovy scripts effectively
• Setting up a compatible IDE
• Creating a new Groovy project
• Managing project dependencies
• Integrating Groovy with existing 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
• Running initial Groovy applications
• Using the println statement for output
• 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
• Use of semicolons and optional syntax elements
• Variables and constants
• Dynamic versus explicit typing
• String literals and interpolation
• Single-line and multiline string handling
• Operators and expressions
• Groovy-specific operators and shortcuts
• Null handling strategies
• Safe navigation operators
• The Elvis operator
• Multiple assignment operations

Using Groovy's Data Types and Collections

• Primitive and object data types
• Numbers and numeric operations
• Strings and character handling
• Boolean values
• Date and time-related values
• Lists
• Maps
• Sets
• Ranges
• Iterating over collections
• Collection transformations
• Filtering and searching within collections
• Sorting and grouping data
• Key Groovy collection methods

Using Groovy Closures

• Understanding the concept of closures
• Closure syntax and structure
• Defining closure parameters
• Using implicit closure parameters
• Invoking closures
• Storing closures as variables
• Passing closures to methods
• Returning closures from methods
• Interacting with collections using closures
• Applying closures for filtering and transformation
• Scope and variable capture
• Leveraging closures for functional programming
• Practical patterns for using closures

Controlling Program Flow with Groovy Control Structures

• Conditional statements
• if and else logic
• Nested conditions
• switch statements
• Loops and iteration mechanisms
• for, while, and do-while loops
• Using ranges in loops
• Applying closures for iteration
• break and continue statements
• Exception handling
• 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
• Working with MetaClass
• Dynamically adding methods
• 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 use of Groovy builders
• Creating hierarchical structures
• Building XML documents
• Generating JSON content
• HTML and markup generation
• Configuring builder output
• Using closures with builders
• Creating custom builder classes
• 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
• Building database functionality for the sample application

Calling Java from Groovy

• Groovy and Java interoperability
• Utilizing Java classes within Groovy
• Calling 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
• Working with request parameters and headers
• Processing JSON responses
• Constructing JSON request bodies
• Handling authentication mechanisms
• 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
• Advanced string manipulation
• Enhanced collection utilities
• File and directory operations
• Reading and writing files
• Working with input and output streams
• Processing XML data
• Processing JSON data
• Working with date and time objects
• Utility methods and convenience APIs
• Selecting appropriate GDK features for specific tasks

Unit Testing a Groovy Application

• Introduction to testing Groovy applications
• Concepts of test-driven development
• Writing effective unit tests
• Using popular testing frameworks
• Structuring test classes
• Using assertions
• Testing classes and individual methods
• Testing closures
• Testing exception handling
• Mocking dependencies
• Data-driven testing techniques
• Testing database-related functionality
• Testing REST integrations
• Running tests and analyzing results

Troubleshooting

• Diagnosing Groovy syntax errors
• Debugging runtime errors
• Resolving compilation problems
• Troubleshooting Java interoperability issues
• Debugging closures and collection operations
• Investigating database connectivity problems
• Troubleshooting REST API integrations
• Debugging meta-programming behavior
• Utilizing logging and diagnostic tools
• Practical troubleshooting exercises

Summary and Conclusion

• Review of Groovy language fundamentals
• Summary of syntax, data types, and collections
• Review of closures and functional programming
• Recap of object-oriented programming concepts
• Review of meta-programming and builder patterns
• Summary of database and REST integration
• Review of Groovy and Java interoperability
• Overview of GDK capabilities
• Summary of testing practices
• Best practices for developing Groovy applications
• Final hands-on exercise
• Q&A and discussion