Functional FooBarQix ...

FooBar.java

package fr.mga.functional;

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

import static java.lang.Character.getNumericValue;
import static java.util.stream.Collectors.joining;

public class FooBar {

    public String imperative(int numberToFoobar) {
        String result = "";
        if(numberToFoobar % 3 == 0) {
            result += "FOO";
        }
        if(numberToFoobar % 5 == 0) {
            result += "BAR";
        }
        if(numberToFoobar % 7 == 0) {
            result += "QIX";
        }
        String toFooBar = String.valueOf(numberToFoobar);
        for (int j = 0; j < toFooBar.length(); j++) {
            char element = toFooBar.charAt(j);
            if(element == '3')
                result += "FOO";
            if(element == '5')
                result += "BAR";
            if(element == '7')
                result += "QIX";

        }
        return result.isEmpty() ? toFooBar : result;
    }

    public String func(int numberToFooBar) {
        Map<Integer, String> foobar = fooBarQix();

        String result = contains(numberToFooBar, foobar);

        String toFooBar = String.valueOf(numberToFooBar);
        result += contains(foobar, toFooBar);
        return result.isEmpty() ? toFooBar : result;
    }

    private String contains(Map<Integer, String> foobar, String toFooBar) {
        return toFooBar.chars()
                    .mapToObj(integerAsChar -> foobar.getOrDefault(getNumericValue(integerAsChar), ""))
                    .collect(joining());
    }

    private String contains(int numberToFooBar, Map<Integer, String> foobar) {
        return foobar.keySet().stream()
                    .filter(toReplace -> numberToFooBar % toReplace == 0)
                    .map(foobar::get)
                    .collect(joining());
    }

    private Map<Integer, String> fooBarQix() {
        Map<Integer, String> foobar = new HashMap<>();
        foobar.put(3, "FOO");
        foobar.put(5, "BAR");
        foobar.put(7, "QIX");
        return foobar;
    }
}

FooBarTest.java

package fr.mga.functional;

import org.fest.assertions.api.Assertions;
import org.junit.Test;

public class FooBarTest {
    @Test
    public void should_make_the_foobar() {
        FooBar fooBar = new FooBar();
        for (int i = 1; i < 101; i++) {
            System.out.println(fooBar.func(i));
            Assertions.assertThat(fooBar.func(i)).isEqualTo(fooBar.imperative(i));
        }
    }
}

Les modifs sont là:
https://gist.github.com/vandekeiser/f52c1325b5cab618de3a

Bien vu, j'ai repris quelques modifs !