Groovy Programming Training Course

Introduction to Groovy

• Overview of Apache Groovy
• Historical background and evolution of the language
• The relationship between Groovy and the Java Virtual Machine
• Groovy’s role as both a scripting and general-purpose programming language
• Common scenarios and use cases for Groovy
• Integrating Groovy into Java-based projects
• Benefits of utilizing Groovy alongside Java
• Presentation of the sample application project

Overview of Groovy Features

• Dynamic typing and optional static typing mechanisms
• Enhanced scripting capabilities
• Concise syntax and modern language enhancements
• Closures and functional programming paradigms
• Groovy collections and enriched API support
• Operator overloading techniques
• String interpolation features
• Safe navigation and the Elvis operator
• Creating Domain-Specific Languages
• Advanced meta-programming capabilities
• The Groovy Development Kit (GDK)

Setting up the Development Environment

• Installation and configuration of Groovy
• Managing different Groovy distributions
• Executing Groovy via the command line
• Running standalone Groovy scripts
• Configuration of an Integrated Development Environment (IDE)
• Initializing a new Groovy project
• Managing project dependencies
• Integrating Groovy into existing Java projects
• Environment setup for containerized applications

Writing Your First Groovy Application

• Creating a fundamental Groovy script
• Analyzing the structure of Groovy scripts
• Executing Groovy applications
• Utilizing the println statement for output
• Managing variables
• Defining custom methods
• Incorporating comments and documentation
• Assembling a basic sample application
• Compiling Groovy source code

Getting Familiar with Groovy's Syntax

• Statements and expressions in Groovy
• Use of semicolons and optional syntax elements
• Handling variables and constants
• Dynamic versus explicit typing
• String literals and interpolation techniques
• Single-line and multiline string handling
• Operators and complex expressions
• Groovy-specific operators and shortcuts
• Null value handling strategies
• Safe navigation operator
• Elvis operator usage
• Multiple assignment patterns

Using Groovy's Data Types and Collections

• Primitive types and object types
• Numeric types and arithmetic operations
• String and character handling
• Boolean logic
• Date and time value management
• Working with Lists
• Working with Maps
• Working with Sets
• Understanding Ranges
• Iterating through collections
• Transforming collection data
• Filtering and searching within collections
• Sorting and grouping data elements
• Groovy-specific collection methods

Using Groovy Closures

• Fundamental concepts of closures
• Closure syntax and structure
• Defining closure parameters
• Implicit closure parameters
• Invoking closures
• Assigning closures to variables
• Passing closures as method arguments
• Returning closures from methods
• Integrating closures with collections
• Applying closures for data filtering and transformation
• Scope management and variable capture
• Functional programming with closures
• Common closure patterns

Controlling Program Flow with Groovy Control Structures

• Conditional logic statements
• Using if and else blocks
• Nested conditional structures
• switch statement implementation
• Loops and iteration mechanisms
• for, while, and do-while loops
• Utilizing ranges within loops
• Closures for iterative tasks
• Control flow with break and continue
• Exception management
• try, catch, and finally blocks
• Raising custom exceptions
• Groovy-specific control-flow enhancements

Implementing Object Oriented Programming (OOP) in Your Application

• Defining classes in Groovy
• Properties and fields
• Constructor definitions
• Method implementation
• Encapsulation principles
• Inheritance mechanisms
• Interface usage
• Abstract classes
• Polymorphism
• Method overriding
• Method overloading
• Groovy getters and setters
• Traits functionality
• Enum types
• Designing 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 extension modules
• MetaClass concepts
• Dynamically adding methods
• Intercepting method calls
• Compile-time transformations
• Standard AST transformations
• Best practices for responsible meta-programming
• Practical meta-programming examples

Working with Builders

• The builder pattern in Groovy
• Purpose and application of Groovy builders
• Constructing hierarchical data structures
• XML generation builders
• JSON generation builders
• HTML and markup generation
• Configuring builder output formats
• Combining closures with builders
• Developing custom builders
• Implementing builders in Domain-Specific Languages

Accessing a Database with Groovy

• Core database connectivity concepts
• Connecting Groovy applications to databases
• JDBC and Groovy-specific database APIs
• Database connection configuration
• Executing SQL queries
• Retrieving and processing query results
• Performing INSERT, UPDATE, and DELETE operations
• Using parameterized queries for security
• Transaction management
• Handling database exceptions
• Utilizing Groovy SQL utilities
• Implementing database features in the sample application

Calling Java from Groovy

• Groovy and Java interoperability
• Utilizing Java classes within Groovy
• Invoking Java methods
• Integrating Java libraries
• Working with Java collections in Groovy
• Handling Java exceptions
• Comparing Groovy and Java syntax
• Calling Groovy code from Java
• Mixing Groovy and Java source files
• Embedding Groovy in existing Java applications
• Interoperability best practices

Connecting to REST Services and Applications

• Introduction to REST APIs
• HTTP concepts relevant to Groovy
• Sending HTTP requests
• Managing GET, POST, PUT, and DELETE methods
• Handling request parameters and headers
• Processing JSON responses
• Constructing JSON request bodies
• Implementing authentication
• 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 standard library APIs
• Advanced string manipulation
• Enhanced collection utilities
• File and directory management
• File reading and writing operations
• Stream handling
• XML processing
• JSON processing
• Date and time utilities
• Utility methods and convenience APIs
• Selecting optimal GDK features

Unit Testing a Groovy Application

• Approaches to testing Groovy applications
• Test-driven development (TDD) principles
• Writing unit tests
• Utilizing testing frameworks
• Structuring test classes
• Using assertions
• Testing individual classes and methods
• Testing closure behavior
• Testing exception handling
• Mocking external dependencies
• Data-driven testing strategies
• Testing database-related logic
• Testing REST integrations
• Executing and interpreting test results

Troubleshooting

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

Summary and Conclusion

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