對兩個不同 class 對象的列表進行排序

Question

我有兩個不同的 class 對象Tracker和Pet的列表，並將這兩個列表組合成一個 class object PetManagement的列表。 現在我想對我的 PetManagement 列表進行排序，例如，與 Pets 鏈接的 Tracker 位於列表的開頭，所有未鏈接的都在后面。 所以最后我的列表應該是這樣的：

position。 追蹤器 - 寵物

0. tracker_one - pet_one
1. tracker_two -...
2. ... - 寵物二

所以我的列表中有 null 對象。 我現在編碼了一段時間並最終進入了很多 for 循環，所以我認為有更好的解決方案來獲得相同的結果。 我擔心我的代碼知道不是真正可讀並且容易產生問題。

注意：在我的Tracker和Pet class 中，我使用唯一的 id 來讓兩者知道哪些是鏈接的，我在兩者中也有一個 boolean（hasTracker/hasPet）。

public class PetManagement {

    private Pet pet;
    private Tracker tracker;

    public PetManagement(Pet pet) {
        this.pet = pet;
    }

    public PetManagement(Tracker tracker) {
        this.tracker = tracker;
    }

    public PetManagement(Pet pet, Tracker tracker) {
        this.pet = pet;
        this.tracker = tracker;
    }

    public Pet getPet() {
        return pet;
    }

    public Tracker getTracker() {
        return tracker;
    }
}

public class Pet {

    private Double id;
    private String name;
    private ImageView picture;
    private String race;
    private float weight;
    private float height;
    private Sex gender;
    private boolean isCastrated;
    private boolean isSterilized;
    private int chipId;
    private boolean hasTracker;
    private Double trackerId;

    public Pet(Double id, String name, ImageView picture, String race, float weight, float height, Sex gender, boolean isCastrated, boolean isSterilized, int chipId, boolean hasTracker, Double trackerId) {
        this.id = id;
        this.name = name;
        this.picture = picture;
        this.race = race;
        this.weight = weight;
        this.height = height;
        this.gender = gender;
        this.isCastrated = isCastrated;
        this.isSterilized = isSterilized;
        this.chipId = chipId;
        this.hasTracker = hasTracker;
        this.trackerId = trackerId;
    }

   getter and setter...
}

public class Tracker {

    private Double id;

    private String serialNum;

    private boolean hasPet;

    private Double petId;

    public Tracker(double id, String serialNum) {
        this.id = id;
        this.serialNum = serialNum;
    }

    public Tracker(Double id, String serialNum, boolean hasPet, Double petId) {
        this.id = id;
        this.serialNum = serialNum;
        this.hasPet = hasPet;
        this.petId = petId;
    }
   
  getter and setter...
}

Answer 1

我只會讓您的 class 具有可比性：

public class PetManagement implements Comparable<PetManagement> {

    ...

    @Override
    public int compareTo(PetManagement other) {
        boolean thisLinked = this.hasTracker() && this.hasPet();
        boolean otherLinked = other.hasTracker() && other.hasPet();

        if (thisLinked && !otherLinked)
            return -1;
        else if (!thisLinked && otherLinked)
            return 1;

        return 0;
    }
}