Groovy 2 Cookbook

What is this book about?

Groovy is an extremely powerful language yet simple and fun to use. It can be used for simple scripting (like Python or bash) or for building complex application. Run-time speed was used to be an issue, but with each release Groovy gets faster and close to native Java performances. The language is not difficult to learn for someone with a Java background and after a bit it becomes clear that Groovy is more fun and productive than Java, mostly because of the excessive verbosity of the Java language. Furthermore, Groovy has features - such as closures - that allow Java developers to try out functional programming and get closer to languages like Scala or Clojure as well as Java 8.

The book contains a number of recipes that put the language to work in different areas of software development and interesting new technologies, such as JSON/REST, DSL, NoSQL. Also, there are non-trivial recipes that can actually be used in real life development.

Why would I read this book?

Groovy cookbook is definitively an interesting read for developers who are attracted by the “getting things done” approach and are ready to get their hands dirty without much ceremony. The recipes in the book can help new developers to get acquainted with the language and experienced ones to access advanced features.

Known side effects

• Religious worship of Groovy
• Might break the time and space barrier by programming so fast
• Envy from other programmers

Chapters

1. Getting Started with Groovy
   Installing Groovy on Windows
   Installing Groovy on Linux
   Executing Groovy code from the command-line
   Using Groovy as a command-line text file editor
   Using Groovy to start server on the command-line
   Running Groovy with invokedynamic support
   Building Groovy from source
   Installing Groovy on Linux
   Using groovysh to try out Groovy commands
   Starting groovyConsole to execute Groovy snippets
   Configuring Groovy in Eclipse
   Configuring Groovy in IntelliJ IDEA
2. Using Groovy Ecosystem
   Using Java classes from Groovy
   Embedding Groovy into Java
   Compiling Groovy code
   Simplifying dependencies management with Grape
   Integrating Groovy into build process using Ant
   Integrating Groovy into build process using Maven
   Integrating Groovy into build process using Gradle
   Generating documentation for Groovy code
   Checking Groovy code quality with CodeNarc
3. Using Groovy Language Features
   Searching strings with regular expressions
   Writing less verbose Java Beans with Groovy Beansa
   Inheriting constructors in Groovy classes
   Adding cloning functionality to Groovy Beans
   Defining code as data in Groovy
   Defining data structures as code in Groovy
   Implementing multiple inheritance in Groovy
   Adding functionality to existing Java/Groovy classes
   Defining type checking rules for dynamic code
   Adding automatic logging to Groovy classes
4. Working with Files in Groovy
   Reading from a file
   Reading a text file line by line
   Processing every word in a text file
   Writing to a file
   Replacing tabs with spaces in a text file
   Filtering a text file content
   Deleting a file or directory
   Walking through a directory recursively
   Searching for files
   Changing file attributes on Windows
   Reading data from a ZIP file
   Reading an Excel file
   Extracting data from a PDF
5. Working with XML in Groovy
   Reading XML using XmlSlurper
   Reading XML using XmlParser
   Reading XML content with namespaces
   Searching in XML with GPath
   Searching in XML with XPath
   Constructing XML content
   Modifying XML content
   Sorting XML nodes
   Serializing Groovy Beans to XML
6. Working with JSON in Groovy
   Parsing JSON messages with JsonSlurper
   Constructing JSON messages with JsonBuilder
   Modifying JSON messages
   Validating JSON messages
   Converting JSON message to XML
   Converting JSON message to Groovy Bean
   Using JSON to configure your scripts
7. Working with Databases in Groovy
   Creating a database table
   Connecting to an SQL database
   Querying an SQL database
   Modifying data in an SQL database
   Calling a stored procedure
   Reading BLOB/CLOB from a database
   Building a simple ORM framework
   Using Groovy to access Redis
   Using Groovy to access MongoDB
   Using Groovy to access Apache Cassandra
8. Working with Web Services in Groovy
   Downloading content from the Internet
   Executing an HTTP GET request
   Executing an HTTP POST request
   Constructing and modifying complex URLs
   Issuing a REST request and parsing a response
   Issuing a SOAP request and parsing a response
   Consuming RSS and ATOM feeds
   Using basic authentication for web service security
   Using OAuth for web service security
9. Metaprogramming and DSLs in Groovy
   Querying methods and properties
   Dynamically extending classes with new methods
   Overriding methods dynamically
   Adding performance logging to methods
   Adding caching functionality around methods
   Adding transparent imports to a script
   DSL for executing commands over SSH
   DSL for generating reports from log files
10. Concurrent Programming with Groovy
    Processing collections concurrently
    Downloading files concurrently
    Splitting a large task into smaller parallel jobs
    Running tasks in parallel and asynchronously
    Using actors to build message-based concurrency
    Using STM to atomically update fields
    Using dataflow variables for lazy evaluation
11. Testing with Groovy
    Unit testing Java code with Groovy
    Testing SOAP web services
    Testing RESTful services
    Writing functional tests for web applications
    Writing behavior-driven tests with Groovy
    Testing the database with Groovy
    Using Groovy in soapUI
    Using JMeter and Groovy for load testing

Cross-References