Groovy Programming Training Course

Introduction to Groovy

• Overview of Apache Groovy
• Historical context and evolution of the language
• Integration with the Java Virtual Machine
• Role as both a scripting and general-purpose programming language
• Typical use cases for Groovy
• Application within Java-based projects
• Benefits of combining Groovy with Java
• Preview of the sample application

Overview of Groovy Features

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

Setting up the Development Environment

• Installation and configuration of Groovy
• Managing different Groovy distributions
• Utilizing Groovy via the command line
• Executing Groovy scripts
• IDE setup and configuration
• Initializing a new Groovy project
• Dependency management strategies
• Integrating Groovy with existing Java projects
• Environment configuration for containerized applications

Writing Your First Groovy Application

• Creating a fundamental Groovy script
• Analyzing Groovy script structure
• Executing Groovy applications
• Utilizing the println statement
• Variable handling and management
• Defining and implementing methods
• Writing comments and documentation
• Developing a basic sample application
• Compiling Groovy code

Getting Familiar with Groovy's Syntax

• Statements and expressions in Groovy
• Use of semicolons and optional syntax elements
• Variables and constant definitions
• Dynamic vs. explicit typing
• String literals and interpolation
• Single-line and multi-line string handling
• Operators and expression evaluation
• Groovy-specific operators and shortcuts
• Null handling mechanisms
• Safe navigation operators
• The Elvis operator
• Multiple assignment techniques

Using Groovy's Data Types and Collections

• Primitive and object-based types
• Numeric operations and number handling
• String and character manipulation
• Boolean logic
• Date and time value handling
• List structures
• Map structures
• Set structures
• Range definitions
• Iterating through collections
• Collection transformation techniques
• Filtering and searching within collections
• Data sorting and grouping
• Groovy-specific collection methods

Using Groovy Closures

• Conceptual understanding of closures
• Closure syntax and structure
• Defining closure parameters
• Implicit closure parameters
• Methods for invoking closures
• Storing closures in variables
• Passing closures as method arguments
• Returning closures from methods
• Interfacing closures with collections
• Applying closures for filtering and transformation
• Scope rules and variable capture
• Leveraging closures for functional programming
• Practical closure patterns

Controlling Program Flow with Groovy Control Structures

• Conditional logic implementation
• if and else statements
• Nested conditional structures
• switch statement usage
• Loops and iteration mechanisms
• for, while, and do-while loops
• Incorporating ranges into loops
• Using closures for iteration
• break and continue control
• Exception handling strategies
• try, catch, and finally blocks
• Throwing and handling custom exceptions
• Groovy-specific control flow features

Implementing Object Oriented Programming (OOP) in Your Application

• Class definition in Groovy
• Properties and field management
• Constructor implementation
• Method definition and usage
• Encapsulation principles
• Inheritance mechanisms
• Interface implementation
• Abstract class usage
• Polymorphism concepts
• Method overriding
• Method overloading
• Groovy getter and setter conventions
• Traits functionality
• Enum usage
• Building domain models for the sample application

Runtime MetaProgramming and Compile Time MetaProgramming

• Introduction to Groovy meta-programming concepts
• Dynamic method invocation
• Expando object usage
• Runtime manipulation of methods and properties
• Categories and extension mechanisms
• MetaClass interaction
• Dynamically adding methods
• Intercepting method calls
• Compile-time transformation techniques
• Common AST transformations
• Best practices for responsible meta-programming
• Practical meta-programming examples

Working with Builders

• Introduction to the builder pattern
• Purpose and utility of Groovy builders
• Constructing hierarchical structures
• XML builder implementation
• JSON builder implementation
• HTML and markup generation
• Configuring builder output formats
• Utilizing closures within builders
• Development of custom builders
• Applying builders in Domain-Specific Languages

Accessing a Database with Groovy

• Core database connectivity concepts
• Establishing connections between Groovy apps and databases
• JDBC and Groovy database API integration
• Database connection configuration
• SQL query execution
• Retrieving and reading query results
• Data insertion, updating, and deletion
• Use of parameterized queries
• Transaction management
• Handling database exceptions
• Utilizing the Groovy SQL module
• Implementing database functionality in the sample app

Calling Java from Groovy

• Groovy-Java interoperability overview
• Accessing Java classes within Groovy
• Invoking Java methods
• Integration with Java libraries
• Utilizing Java collections
• Handling Java exceptions in Groovy
• Comparing Groovy and Java syntax
• Calling Groovy code from Java
• Mixing Groovy and Java source files
• Integrating Groovy into legacy Java applications
• Interoperability best practices

Connecting to REST Services and Applications

• Introduction to REST API interactions
• HTTP concepts relevant to Groovy
• Constructing and sending HTTP requests
• Handling GET, POST, PUT, and DELETE operations
• Managing request parameters and headers
• Parsing JSON responses
• Creating JSON request payloads
• Authentication handling
• Managing HTTP error responses
• Consuming external REST services
• Integrating REST capabilities into the sample application

Working with the GDK

• Introduction to the Groovy Development Kit
• Enhanced Java API features
• String manipulation utilities
• Enhanced collection operations
• File and directory management
• File reading and writing operations
• Stream processing
• XML processing capabilities
• JSON processing capabilities
• Date and time manipulation
• Utility methods and convenience APIs
• Selecting the appropriate GDK tools for tasks

Unit Testing a Groovy Application

• Overview of testing strategies for Groovy
• Test-driven development (TDD) principles
• Writing effective unit tests
• Integration of testing frameworks
• Structuring test classes and methods
• Using assertions
• Testing class and method logic
• Testing closure behavior
• Exception testing scenarios
• Mocking external dependencies
• Data-driven testing approaches
• Testing database interactions
• Testing REST API integrations
• Executing tests and analyzing results

Troubleshooting

• Diagnosing Groovy syntax errors
• Debugging runtime issues
• Resolving compilation problems
• Troubleshooting Java interoperability challenges
• Debugging closure and collection operations
• Investigating database connectivity issues
• Troubleshooting REST API integration problems
• Debugging meta-programming side effects
• Leveraging logging and diagnostic tools
• Practical troubleshooting drills

Summary and Conclusion

• Recap of Groovy language fundamentals
• Review of syntax, data types, and collections
• Summary of closures and functional programming
• Review of object-oriented programming concepts
• Summary of meta-programming and builder patterns
• Review of database and REST integrations
• Review of Groovy and Java interoperability
• Summary of GDK capabilities
• Review of testing best practices
• Best practices for Groovy application development
• Final practical exercise
• Open questions and discussion