Book Image

Transitioning to Java

By : Ken Fogel
Book Image

Transitioning to Java

By: Ken Fogel

Overview of this book

This comprehensive guide will help non-Java developers already using different languages transition from their current language to all things Java. The chapters are designed in a way that re-enforces a developer’s existing knowledge of object-oriented methodologies as they apply to Java. This book has been divided into four sections, with each section touching upon different aspects that’ll enable your effective transition. The first section helps you get to grips with the Java development environment and the Maven build tool for modern Java applications. In the second section, you’ll learn about Java language fundamentals, along with exploring object-oriented programming (OOP) methodologies and functional programming and discovering how to implement software design patterns in Java. The third section shows you how to code in Java on different platforms and helps you get familiar with the challenges faced on these platforms. In the fourth section, you’ll find out how you can manage and package your Java code. By the end of this Java programming book, you’ll have learned the core concepts of Java that’ll help you successfully transition from a different language to Java.
Table of Contents (23 chapters)
1
Part 1:The Java Development Environment
5
Part 2:Language Fundamentals
15
Part 3:GUI and Web Coding in Java
19
Part 4:Packaging Java Code

Launch Single-File Source-Code Programs

Before Java 11, the process of going from source code to execution was a two-step process: you compiled the code and then ran the code. Beginning with Java 11, another way to run a Java program was introduced, called Launch Single-File Source-Code Programs. This allows you to compile, start up the JVM, and execute the program in a single line. We’ll see how this works for Windows, macOS, and Linux before examining a unique way for Linux and macOS.

For Windows, macOS, and Linux

Open a Command Prompt or Terminal in the same folder as the file you wish to run and, if necessary, update the Path and JAVA_HOME properties. Now, simply enter java and the name of the source file:

Figure 2.9 – Running a Java program

Figure 2.9 – Running a Java program

As the name of this technique implies, your program can only consist of a single file. This source file may contain more than one class and the first class in the file must have a main method...