Java Coding Problems

166. Writing functional interfaces

In this solution, we will highlight the purpose and usability of a functional interface in comparison with several alternatives. We will look at how to evolve the code from its basic and rigid implementation to a flexible implementation based on a functional interface. For this, let's consider the following Melon class:

public class Melon {  private final String type;  private final int weight;  private final String origin;  public Melon(String type, int weight, String origin) {    this.type = type;    this.weight = weight;    this.origin = origin;  }  // getters, toString(), and so on omitted for brevity}

Let's assume that we have a client – let's call him Mark – who wants to start up a melon-selling business. We shaped ...