97 Things Every Java Programmer Should Know

Chapter 53. Learn to Use New Java Features

Gail C. Anderson

Java 8 introduced lambdas and streams, two game-changing features that give Java programmers significant language constructs. From Java 9 onward, release cycles occur every six months with more features popping up in each release. You should care about these new features because they help you write better code. And, your skills will improve as you incorporate new language paradigms into your programming arsenal.

Much has been written about streams and how they support a functional programming style, reduce bulky code, and make code more readable. So, let’s look at an example with streams, not so much to convince you to use streams everywhere but to entice you to learn about this and other Java features introduced since Java 8.

Our example computes the maximum, average, and minimum for systolic, diastolic, and pulse values from collected blood-pressure monitoring data. We want to visualize these computed summary statistics with a JavaFX bar chart.

Here’s a portion of our BPData model class, showing just the getter methods we need:

public class BPData {
  ...
  public final Integer getSystolic() {
    return systolic.get();
  }
  public final Integer getDiastolic() {
    return diastolic.get();
  }
  public final Integer getPulse() {
    return pulse.get();
  }
  ...
}

The JavaFX bar chart creates the magic for this visualization. First, we need ...