Groovy Programming Training Course

Introduction to Groovy

• Overview of Apache Groovy
• Historical background and evolution
• Relationship with the Java Virtual Machine
• Groovy as a language for both scripting and application development
• Typical use cases for Groovy
• Integration within Java-based projects
• Benefits of pairing Groovy with Java
• Introduction to the sample project

Overview of Groovy Features

• Dynamic typing and the option for static typing
• Scripting capabilities
• Concise syntax and language enhancements
• Closures and functional programming concepts
• Enhanced collection APIs
• Operator overloading
• String interpolation
• Safe navigation and the Elvis operator
• Creating Domain-Specific Languages
• Meta-programming capabilities
• The Groovy Development Kit (GDK)

Setting up the Development Environment

• Installation and configuration steps
• Working with different Groovy distributions
• Executing Groovy from the command line
• Running scripts
• Configuring an IDE
• Creating a new Groovy project
• Managing dependencies
• Integrating Groovy with existing Java projects
• Configuring the environment for containerized deployments

Writing Your First Groovy Application

• Creating a basic script
• Understanding script structure
• Running applications
• Using the println statement
• Working with variables
• Defining methods
• Adding comments and documentation
• Building a simple sample application
• Compiling code

Getting Familiar with Groovy's Syntax

• Statements and expressions
• Optional semicolons and syntax elements
• Variables and constants
• Dynamic versus explicit typing
• String literals and interpolation
• Single-line and multi-line strings
• Operators and expressions
• Unique Groovy operators and shortcuts
• Null handling
• Safe navigation
• The Elvis operator
• Multiple assignment

Using Groovy's Data Types and Collections

• Primitive and object types
• Numeric operations
• Strings and characters
• Booleans
• Date and time values
• Lists
• Maps
• Sets
• Ranges
• Iterating over collections
• Transforming collections
• Filtering and searching
• Sorting and grouping data
• Collection methods

Using Groovy Closures

• Concept of closures
• Syntax
• Parameters
• Implicit parameters
• Invoking closures
• Using closures as variables
• Passing closures to methods
• Returning closures
• Closures and collections
• Filtering and transformation
• Scope and variable capture
• Functional programming patterns
• Practical usage patterns

Controlling Program Flow with Groovy Control Structures

• Conditional statements
• if and else blocks
• Nested conditions
• switch statements
• Loops and iteration
• for, while, and do-while loops
• Using ranges in loops
• Iterating with closures
• break and continue
• Exception handling
• try, catch, and finally blocks
• Throwing custom exceptions
• Groovy-specific flow control

Implementing Object Oriented Programming (OOP) in Your Application

• Defining classes
• Properties and fields
• Constructors
• Methods
• Encapsulation
• Inheritance
• Interfaces
• Abstract classes
• Polymorphism
• Method overriding
• Method overloading
• Getters and setters
• Traits
• Enums
• Creating domain models for the sample app

Runtime MetaProgramming and Compile Time MetaProgramming

• Introduction to meta-programming
• Dynamic method invocation
• Expando objects
• Manipulating methods and properties at runtime
• Categories and extensions
• The MetaClass
• Dynamic method addition
• Intercepting calls
• Compile-time transformations
• Common AST transformations
• Responsible usage of meta-programming
• Practical examples

Working with Builders

• The builder pattern
• Purpose of Groovy builders
• Creating hierarchical structures
• XML builders
• JSON builders
• HTML and markup generation
• Configuring output
• Using closures with builders
• Creating custom builders
• Applications in Domain-Specific Languages

Accessing a Database with Groovy

• Connectivity concepts
• Connecting applications to databases
• JDBC and Groovy database APIs
• Configuration of connections
• Executing SQL queries
• Reading results
• Insert, update, and delete operations
• Parameterized queries
• Transactions
• Handling exceptions
• Groovy SQL
• Building database features for the sample app

Calling Java from Groovy

• Interoperability concepts
• Using Java classes
• Invoking Java methods
• Working with Java libraries
• Using Java collections
• Handling Java exceptions
• Syntax comparison
• Calling Groovy from Java
• Mixing source files
• Integrating into Java applications
• Best practices

Connecting to REST Services and Applications

• REST API overview
• HTTP concepts
• Sending requests
• GET, POST, PUT, and DELETE operations
• Parameters and headers
• Processing JSON responses
• Building JSON bodies
• Authentication
• Error management
• Consuming external services
• Integrating REST into the sample app

Working with the GDK

• Introduction to the Groovy Development Kit
• Enhanced Java APIs
• String manipulation
• Enhanced collections
• File and directory operations
• File I/O
• Stream processing
• XML processing
• JSON processing
• Date and time handling
• Utility methods
• Selecting appropriate tools

Unit Testing a Groovy Application

• Testing overview
• Test-driven development
• Writing unit tests
• Using frameworks
• Structuring test classes
• Assertions
• Testing classes and methods
• Testing closures
• Testing exceptions
• Mocking
• Data-driven tests
• Testing database functionality
• Testing REST integrations
• Running and analyzing results

Troubleshooting

• Diagnosing syntax errors
• Debugging runtime issues
• Compilation problems
• Java interoperability issues
• Debugging closures and collections
• Database connectivity problems
• REST API issues
• Meta-programming behavior
• Logging and diagnostics
• Practical exercises

Summary and Conclusion

• Review of fundamentals
• Review of syntax and types
• Review of closures
• Review of OOP
• Review of meta-programming and builders
• Review of database and REST integration
• Review of Java interoperability
• Review of GDK
• Review of testing
• Best practices
• Final hands-on exercise
• Questions and discussion