Java Coding Problems

50. Passing/returning mutable objects to/from an immutable class

Passing mutable objects to an immutable class can break down immutability. Let's consider the following mutable class:

public class Radius {  private int start;  private int end;  public int getStart() {    return start;  }  public void setStart(int start) {    this.start = start;  }  public int getEnd() {    return end;  }  public void setEnd(int end) {    this.end = end;  }}

Then, let's pass an instance of this class to an immutable class named, Point. At first glance, the Point class can be written as follows:

public final class Point {  private final double x;  private final double y;  private final Radius radius;  public Point(double x, double y, Radius radius) {    this.x = x;    this.y = y; this.radius ...