任何人都可以使用泛型和可比较接口为我的任务提供解决方案吗？

Question

I wrote half of it but cannot get it 100% correct. Can anyone help me with it?

Here is my problem:

Write a parameterized class Triple that represents a trio of some type (eg, the Three of String, the Integer , etc.). For Triple class define:

-getElement method that receives an integer number (1,2 or 3) and returns the corresponding member. In the case of an illegal argument, throw an IllegalArgumentExpression exception -setElement that receives two arguments: an integer number (1, 2 or 3) and the value to be placed as a member of the three in the corresponding position (eg, setElement(2,3) sets 3 to y value of trio) -a constructor with 3 arguments that set the initial values of the Triple

Then you should write the ComparableTriple class, which represents the triplet. Members of triplet must be comparable (implement Comparable interface). Then expand the ComparableTriple class to implement the Comparable interface, so that triplets can be comparable by positions. For example ,(2,6,1) is in the rank before (3,4,5) but behind (2,6, -4). Same template can be applied to String etc.

Example of main code:

Triple t1 = new ComparableTriple<>(2, 6, 1); int x = t1.compareTo(t1); // should be 0

//Triple class I wrote 

public class Triple<T> {
    T x, y, z;

    public Triple(T x, T y, T z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }
    public T getElement(int position) {
        if (position == 1) {
            return x;
        } else if (position == 2) {
            return y;
        } else if (position == 3) {
            return z;
        } else throw new IllegalArgumentException();
    }
    public void setElement(int position, T value) {
        if (position == 1) {
            x = value;
        } else if (position == 2) {
            y = value;
        } else if (position == 3) {
            z = value;
        } else throw new IllegalArgumentException(); }
}

I tried writing ComparableTriple overriding CompareTo method but couldn't find the exact solution. It's not so complicated but I'm new to Generics and can't figure some things out. Can anyone help me about the rest of code?

Answer 1

public class Triple<T> implements Comparable<Triple<T>> {
  ... your code here
// functional interface Comparable will force you to override the method
}

But you may want to have some kind of superclass that T extends so you can access fields for the compare.

Example:

public class Triple<T extends Number> implements Comparable<Triple<T>>

There is of course the inline compare with Collections.sort(comparable) if you don't want to commit to what T is.

That should get you started. Post back/edit if you get stuck. Cheers.

(And this is not a solution by intent). Generics are a pain and need to be slogged through to get good at.