Subversion Repositories SmartDukaan

package com.spice.profitmandi.service.order;

import java.util.NavigableMap;

import java.util.Random;

import java.util.TreeMap;

public class RandomCollection<E> {

    private final NavigableMap<Double, E> map = new TreeMap<>();

    private final Random random;

    private double total = 0;

    public RandomCollection() {

        this(new Random());

    }

    public RandomCollection(Random random) {

        this.random = random;

    }

    public RandomCollection<E> add(double weight, E result) {

        if (weight <= 0) return this;

        total += weight;

        map.put(total, result);

        return this;

    }

    public E next() {

        double value = random.nextDouble() * total;

        return map.higherEntry(value).getValue();

    }

    public int size() {

        return map.size();

    }

}