I'm trying to make a compareTo method that I use to sort a list in the order of the following colors: white, yellow, orange, red, blue, purple, black. Where white is the first color.
I have an object Fruit which contains different types of fruit, these fruits are specified in extended classes. All fruits have a color (which also is in the list of colors).
I was trying to write an if-else statement so that if the color of the fruit is yellow return 1 etc. and that for all colors. But that didn't seem to work.
Can anybody help me to write the compareTo method?
Thanks in advance!
My abstract Fruit class where I implement the compareTo method:
public abstract class Fruit implements Comparable<Fruit>, Edible {
String name;
Color color;
boolean fluid;
public Fruit(String name, Color color, boolean fluid) {
this.name = name;
this.color = color;
this.fluid = fluid;
}
public abstract boolean isRotten();
@Override // I don't know how to create this one correctly
public int compareTo(Fruit fruit) {
if (this.getColor().getName().equals("white")){
return 0;
}
if (this.getColor().getName().equals("yellow")){
return 1;
}
if (this.getColor().getName().equals("orange")){
return 2;
}
if (this.getColor().getName().equals("red")){
return 3;
}
if (this.getColor().getName().equals("blue")){
return 4;
}
if (this.getColor().getName().equals("purple")){
return 5;
}
if (this.getColor().getName().equals("black")){
return 6;
}
else return -1;
}
public Color getColor() {
return color;
}
@Override
public boolean isEdible() {
return !isRotten();
}
}
The class for Color:
public class Color {
private String name;
public static final String WHITE = "white";
public static final String YELLOW = "yellow";
public static final String ORANGE = "orange";
public static final String RED = "red";
public static final String BLUE = "blue";
public static final String PURPLE = "purple";
public static final String BLACK = "black";
public String getName() {
return name;
}
public Color(String name) {
this.name = name;
}
}
The class where I add the different fruits to a list and sort the list:
public class FruitSortingMachine {
private List<Fruit> fruits = new ArrayList<>();
/**
* Instantiates a new Fruit sorting machine.
*/
public FruitSortingMachine(){}
/**
* Sort.
*/
public void sort() {
Collections.sort(fruits);
}
/**
* Gets fruits.
*
* @return the fruits
*/
public List<Fruit> getFruits() {
return this.fruits;
}
/**
* Add fruit boolean.
*
* @param fruit the fruit
* @return the boolean
*/
public boolean addFruit(Fruit fruit) {
if (!fruit.isEdible()){
return false;
}
else this.fruits.add(fruit);
return true;
}
}
I'd turn Color into enum:
public enum Color {
WHITE("white", 0),
YELLOW("yellow", 1),
ORANGE = "orange", 2),
RED("red", 3),
BLUE("blue", 4),
PURPLE("purple", 5),
BLACK("black", 6);
private String name;
private int order;
// getters, setters etc.
}
Then you can compare the Colors by the order field:
@Override
public int compareTo(Fruit fruit) {
return Integer.compare(this.getColor().getOrder(), fruit.getColor().getOrder());
}