Integration with Java

Many people think Groovy is a scripting language. Yes, it provides scripting support, but it's not right to say Groovy is only a scripting language. Along with scripting, it perfectly fits into the OOP world. As mentioned earlier, Groovy also provides seamless integration with Java. Calling Java from Groovy is as simple as writing Groovy code. Every Groovy type is a subtype of java.lang.Object.

Minimum code

One good thing about Groovy is that it reduces the amount of code required to do some complex tasks, such as parsing XML files and accessing databases. With Groovy, you can always mix in Java code. If you've been using Java for a while, I think you'll appreciate the simplicity of using Groovy since you can program more functionality by writing less code.

Simpler I/O operations

I/O operations, one of the main pain points for the developer while working with Java, is made much simpler in Groovy. It's more fun to perform I/O operations in Groovy. Groovy provides simple properties to read/write from the file. It has added so many utility methods to the java.io.File class.

Integration with Ant

Like Java, Groovy provides seamless integration with Ant. Groovy has a helper class, AntBuilder, which gives Groovy the power of using Ant features to make the developer's life much simpler. Be it calculating the checksum of any file or copying the content of a directory from one location to another with any filter criteria. With Ant capabilities, Groovy makes developers more productive. In Chapter 8, Migration, we will discuss more on this topic.

Builder classes

Apart from AntBuilder, Groovy provides the capability of NodeBuilder, MarkupBuilder, and SwingBuilder. With the help of these Builders, the developer is able to achieve things in a much simpler way, as compared to life without the Builders. MarkupBuilder is useful while dealing with XML operations. SwingBuilder provides simplified API to the Swing framework that helps in building user-friendly GUI applications. NodeBuilder helps while working with object tree structure.

Closure

The inclusion of closures was a big selling point for Groovy. A closure in Groovy is an anonymous chunk of code that may take arguments, return a value, and reference and use variables declared in its surrounding scope. Closure has usually been associated with functional languages.

A Groovy closure is like a code block that is defined and then executed at a later point. It has some special properties such as implicit variables and free variables. We will discuss Closure in detail in later section of this chapter.

Of course, there are many more features to learn. We will discuss a few in this chapter. For more details refer to the Groovy documentation at http://www.groovy-lang.org/.