- Mastering Gradle
- Mainak Mitra
- 687字
- 2021-07-16 20:49:35
Overview
Groovy is a dynamic programming language for the Java Platform. You might be wondering why we specifically mention the Java platform. By the Java platform, it means Groovy code compiles into the bytecode, and bytecodes are executed on JVM similar to any other Java class. Along with the OOP features, it also provides the capability of scripting languages such as Python and Smalltalk, making them available to use in Groovy using a Java-like syntax.
As Groovy runs on JVM, it can be easily integrated with Java and nicely fits into the existing infrastructure. For example, the build and deployment of Groovy code is the same as the build and deployment of Java code, and you can easily mix Groovy and Java together by just adding another JAR file to the library. Groovy is not the only language that runs on JVM. Some of the other languages are Scala, Clojure, JRuby, Jython, and so on. In my opinion, if you have some Java background, Groovy is much easier to learn when compared with other languages. It has a very Java-like syntax to it, and most of the Java syntaxes are valid Groovy syntaxes. It just simplifies coding. Groovy is never intended to replace Java. It is intended to supplement Java to extend it to make it easier, and also it uses modern language features such as closures, builders, and metaprogramming.
The following are some of the key features of Groovy.
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/.