// It's always useful to define these methods
// toString should return a String that represents the object
public String toString() {
String out = givenName + " " + familyName + " is " + age + " years old.";
if (parent != null) {
out += "\nParent: " + parent.toString();
}
return out;
}
// equals should return true only when the two objects are considered equal
// Not all variables need to be equal though, you can decide on equality
// however you like
public boolean equals(BadMutablePerson p) {
if (!this.familyName.equals(p.getFamilyName())) {
return false;
}
if (!this.givenName.equals(p.getGivenName())) {
return false;
}
if (this.age != p.getAge()) {
return false;
}
if (this.parent != null && p.getParent() != null && !this.parent.equals(p.getParent())) {
return false;
}
if ((this.parent == null && p.getParent() != null)
|| (this.parent != null && p.getParent() == null)) {
return false;
}
return true;
}
public static void main(String args[]) {
// Let's create a few objects
BadMutablePerson p1 = new BadMutablePerson("", "Mr. Incredible", 37, null);
BadMutablePerson p2 = new BadMutablePerson("", "Elastigirl", 35);
BadMutablePerson p3 = new BadMutablePerson("Parr", "Dash", 13, p1);
BadMutablePerson p4 = new BadMutablePerson("Parr", "Violet", 17, p1);
BadMutablePerson p5 = p1;
// We can use toString to print a representation of the object
System.out.println("\nTESTING TOSTRING METHOD");
System.out.println(p1.toString());
// Java is smart enough that you don't actually need to call the method
System.out.println(p2);
System.out.println(p3);
// Now let's try the equals method; this should print false
System.out.println("\nTESTING EQUALS METHOD");
System.out.println(
"Testing p1 with p4, expecting false as they are "
+ " different objects: "
+ p1.equals(p4));
System.out.println(
"Testing p4 with p1, expecting false as they are "
+ " different objects: "
+ p4.equals(p1));
System.out.println(
"Testing p1 with p2, expecting false as they are "
+ " different objects: "
+ p1.equals(p2));
// This is true
System.out.println(
"Testing p1 with p1, expecting true as they are " + " the same objects: " + p1.equals(p1));
System.out.println(
"Testing p1 with p5, expecting true as they "
+ "point to the same object: "
+ p1.equals(p5));
System.out.println(
"Testing parent of p3 with parent of p4, "
+ "expecting true, same parent: "
+ p3.getParent().equals(p4.getParent()));
// We can now modify our objects because of the set methods
System.out.println("\nTESTING SETTERS");
// Here is the starting object
System.out.println(p1);
// Now we modify it and check again
p1.setAge(20);
System.out.println(p1);
p1.setFamilyName("Parr");
System.out.println(p5);
// Let's make sure we've prevented privacy leaks
System.out.println("\nTESTING PRIVACY LEAKS");
System.out.println(p3);
System.out.println(p4);
p1.setFamilyName("");
System.out.println(p3);
System.out.println(p4);
System.out.println("\nUh oh...");
}
