Roman Numeral Kata in Java

Number.java

public class Number implements Comparable<Number> {

	private int arabic;
	private String roman;

	public Number(int arabicIn, String romanIn) {
		arabic = arabicIn;
		roman = romanIn;
	}

	public int getArabic() {
		return this.arabic;
	}

	public String getRoman() {
		return this.roman;
	}


	@Override
	public int compareTo(Number number) {

		if(this.getArabic() > number.getArabic())
			return 1;

		else if(this.getArabic() < number.getArabic())
			return -1;

		else return 0;
	}
}

RomanNumbers.java

import java.util.*;

public class RomanNumbers {

	private static List<Number> dictionary = new ArrayList<>();

	static {
		dictionary.add(new Number(50, "L"));
		dictionary.add(new Number(40, "XL"));
		dictionary.add(new Number(10, "X"));
		dictionary.add(new Number(9, "IX"));
		dictionary.add(new Number(5, "V"));
		dictionary.add(new Number(4, "IV"));
		dictionary.add(new Number(1, "I"));
	}


	public String convertToRoman(int arabicInput) {

		StringBuffer result = new StringBuffer();

		for(Number item : dictionary) {

			while (arabicInput >= item.getArabic()) {
				result.append(item.getRoman());
				arabicInput -= item.getArabic();
			}
		}

		return result.toString();
	}
}

RomanNumberTest.java

public class RomanNumbersTest {

	@Test
	public void convertArabicToRomanNumbers() {
		RomanNumbers converter = new RomanNumbers();
		assertThat(converter.convertToRoman(1), is(equalTo("I")));
		assertThat(converter.convertToRoman(2), is(equalTo("II")));
		assertThat(converter.convertToRoman(3), is(equalTo("III")));
		assertThat(converter.convertToRoman(4), is(equalTo("IV")));
		assertThat(converter.convertToRoman(5), is(equalTo("V")));
		assertThat(converter.convertToRoman(6), is(equalTo("VI")));
		assertThat(converter.convertToRoman(7), is(equalTo("VII")));
		assertThat(converter.convertToRoman(9), is(equalTo("IX")));
		assertThat(converter.convertToRoman(10), is(equalTo("X")));
		assertThat(converter.convertToRoman(11), is(equalTo("XI")));
		assertThat(converter.convertToRoman(40), is(equalTo("XL")));
		assertThat(converter.convertToRoman(50), is(equalTo("L")));
		assertThat(converter.convertToRoman(55), is(equalTo("LV")));
		assertThat(converter.convertToRoman(60), is(equalTo("LX")));
	}


}