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

Using BigDecimal

The BigDecimal class, which is a member of the java.math library, is a fixed-precision representation of floating point numbers. This means that values represented as BigDecimal do not suffer from the problem of approximation that can and does occur when calculations are carried out by the hardware floating point unit (FPU) of most CPUs.

The BigDecimal class shares an important characteristic with a string. They are both immutable. This means that when a value becomes a BigDecimal object, it cannot be changed. Any operation on a BigDecimal object returns a new BigDecimal object.

Let us look at an application that can calculate loan payments for money borrowed. The formula for this calculation is as follows:

Here:

  • rate = the interest rate per period
  • n = the number of periods
  • PV = present value (amount of loan)
  • PMT = payment (the monthly payment)

If we use doubles for all the values, the Java bean data object...