Class for getting random items with given probabilities

Probabilities.java

import java.util.HashMap;
import java.util.Map;
import java.util.Random;

public class Probabilities<T> {

    private static Random random = new Random();

    private Map<T, Float> items;

    public Probabilities() {
        items = new HashMap<>();
    }

    public void add(T item, float prob) { items.put(item, prob); }
    public void remove(T item) { items.remove(item); }

    public Map<T, Float> getItems() { return new HashMap<>(items); }

    public T randomItem() {
        float total = 0;

        for (float proba : items.values()) {
            total += proba;
        }

        float randomNum = random.nextFloat();
        randomNum *= total;

        float cur = 0;
        for(T item : items.keySet()) {
            float proba = items.get(item);

            if(randomNum >= cur && randomNum < cur + proba) {
                return item;
            }

            cur += proba;
        }

        return items.keySet().stream().findFirst().orElse(null);
    }

}

Usage example:

Probabilities<String> probs = new Probabilities<>();
probs.add("Hello", 50);
probs.add("Bonjour", 25);
probs.add("Ciao", 25);

String helloMessage = probs.randomItem();
System.out.println(helloMessage);

/*
    Here, helloMessage has a 50% chance to be "Hello", 25% chance to be "Bonjour" and 25% chance to be "Ciao".
    The total of this example is 100 for better understanding, but it can be any number you want.
*/