Book Image

Introduction to JVM Languages

Book Image

Introduction to JVM Languages

Overview of this book

Anyone who knows software development knows about the Java Virtual Machine. The Java Virtual Machine is responsible for interpreting Java byte code and translating it into actions. In the beginning, Java was the only programming language used for the JVM. But increasing complexity of the language and the remarkable performance of the JVM created an opening for a new generation of programming languages. If you want to build a strong foundation with the Java Virtual Machine and get started with popular modern programming languages, then this book is for you. The book will begin with a general introduction of the JVM and its features, which are common to the JVM languages, helping you get abreast with its concepts. It will then dive into explaining languages such as Java, Scala, Clojure, Kotlin, and Groovy and will show how to work with each language, their features, use cases, and pros and cons. By writing example projects in those languages and focusing on each language’s strong points, it will help you find the programming language that is most appropriate for your particular needs. By the end of the book, you will have written multiple programs that run on the Java Virtual Machine and know about the differences between the various languages.
Table of Contents (15 chapters)

Generating XML using MarkupBuilder


Groovy's XML MarkupBuilder class is an example of a class that has been created using Groovy's dynamic programming features. We looked at dynamically intercepting method calls in the previous chapter, something that would be impossible to implement in such a seamless way in a static language, such as Java or Kotlin.

For illustration, here's an example code using the Groovy's XML MarkupBuilder class. There's no need to enter this code in the Eclipse IDE yet, but you could enter this code in GroovyConsole and run it there:

    def xmlContent = new StringWriter()
    def xmlWriter = new groovy.xml.MarkupBuilder(xmlContent)
    xmlWriter.items {    
      item(id: 1) {
        name("Item one")
      }
      item(id: 2) {
        name("Item two")
      }
    }
    println(xmlContent)

A lot is happening in the preceding code. However, before we take a detailed look at it, let's look at the result. The preceding code will print the following output to the console...