Cómo convertir números a palabras en java

Actualmente tenemos un mecanismo burdo para convertir números en palabras (por ejemplo, usando algunas matrices estáticas) y, en función del tamaño del número, traducirlo a un texto en inglés. Pero nos encontramos con problemas relacionados con cifras que son enormes.

10183 = Ten thousand one hundred eighty three
90 = Ninety
5888 = Five thousand eight hundred eighty eight

¿Existe una función fácil de usar en alguna de las bibliotecas matemáticas que pueda usar para este propósito?

Oct 12 '10 12:10 Jason

ICU4J contiene un buen soporte para deletrear números. Los archivos con las "reglas" se pueden editar fácilmente y no hay problema en agregar otros idiomas (lo hicimos, por ejemplo, para polaco y ruso).

Oct 12 '2010 09:10 Landei

Porque no se puede tener un algoritmo general para cada ubicación, no. Debe implementar su propio algoritmo para cada configuración regional que admita.

** EDITAR **

Sólo por el gusto de hacerlo, jugué hasta que obtuve esta clase.No se puede mostrar Long.MIN_VALUEdebido a restricciones de bits... pero supongo que podría modificarse y cambiar longlos tipos de valores a doublenúmeros decimales o incluso mayores.Puede mostrar cualquier número de hasta 66 dígitos y 26 decimales utilizando una representación de cadena del número. Puedes agregar más ScaleUnitpara obtener más decimales...

/**
 * This class will convert numeric values into an english representation
 * 
 * For units, see : http://www.jimloy.com/math/billion.htm
 * 
 * @author [email protected]
 */
public class NumberToWords {

    static public class ScaleUnit {
        private int exponent;
        private String[] names;
        private ScaleUnit(int exponent, String...names) {
            this.exponent = exponent;
            this.names = names;
        }
        public int getExponent() {
            return exponent;
        }
        public String getName(int index) {
            return names[index];
        }
    }

    /**
     * See http://www.wordiq.com/definition/Names_of_large_numbers
     */
    static private ScaleUnit[] SCALE_UNITS = new ScaleUnit[] {
        new ScaleUnit(63, "vigintillion", "decilliard"),
        new ScaleUnit(60, "novemdecillion", "decillion"),
        new ScaleUnit(57, "octodecillion", "nonilliard"),
        new ScaleUnit(54, "septendecillion", "nonillion"),
        new ScaleUnit(51, "sexdecillion", "octilliard"),
        new ScaleUnit(48, "quindecillion", "octillion"),
        new ScaleUnit(45, "quattuordecillion", "septilliard"),
        new ScaleUnit(42, "tredecillion", "septillion"),
        new ScaleUnit(39, "duodecillion", "sextilliard"),
        new ScaleUnit(36, "undecillion", "sextillion"),
        new ScaleUnit(33, "decillion", "quintilliard"),
        new ScaleUnit(30, "nonillion", "quintillion"),
        new ScaleUnit(27, "octillion", "quadrilliard"),
        new ScaleUnit(24, "septillion", "quadrillion"),
        new ScaleUnit(21, "sextillion", "trilliard"),
        new ScaleUnit(18, "quintillion", "trillion"),
        new ScaleUnit(15, "quadrillion", "billiard"),
        new ScaleUnit(12, "trillion", "billion"),
        new ScaleUnit(9, "billion", "milliard"),
        new ScaleUnit(6, "million", "million"),
        new ScaleUnit(3, "thousand", "thousand"),
        new ScaleUnit(2, "hundred", "hundred"),
        //new ScaleUnit(1, "ten", "ten"),
        //new ScaleUnit(0, "one", "one"),
        new ScaleUnit(-1, "tenth", "tenth"),
        new ScaleUnit(-2, "hundredth", "hundredth"),
        new ScaleUnit(-3, "thousandth", "thousandth"),
        new ScaleUnit(-4, "ten-thousandth", "ten-thousandth"),
        new ScaleUnit(-5, "hundred-thousandth", "hundred-thousandth"),
        new ScaleUnit(-6, "millionth", "millionth"),
        new ScaleUnit(-7, "ten-millionth", "ten-millionth"),
        new ScaleUnit(-8, "hundred-millionth", "hundred-millionth"),
        new ScaleUnit(-9, "billionth", "milliardth"),
        new ScaleUnit(-10, "ten-billionth", "ten-milliardth"),
        new ScaleUnit(-11, "hundred-billionth", "hundred-milliardth"),
        new ScaleUnit(-12, "trillionth", "billionth"),
        new ScaleUnit(-13, "ten-trillionth", "ten-billionth"),
        new ScaleUnit(-14, "hundred-trillionth", "hundred-billionth"),
        new ScaleUnit(-15, "quadrillionth", "billiardth"),
        new ScaleUnit(-16, "ten-quadrillionth", "ten-billiardth"),
        new ScaleUnit(-17, "hundred-quadrillionth", "hundred-billiardth"),
        new ScaleUnit(-18, "quintillionth", "trillionth"),
        new ScaleUnit(-19, "ten-quintillionth", "ten-trillionth"),
        new ScaleUnit(-20, "hundred-quintillionth", "hundred-trillionth"),
        new ScaleUnit(-21, "sextillionth", "trilliardth"),
        new ScaleUnit(-22, "ten-sextillionth", "ten-trilliardth"),
        new ScaleUnit(-23, "hundred-sextillionth", "hundred-trilliardth"),
        new ScaleUnit(-24, "septillionth","quadrillionth"),
        new ScaleUnit(-25, "ten-septillionth","ten-quadrillionth"),
        new ScaleUnit(-26, "hundred-septillionth","hundred-quadrillionth"),
    };

    static public enum Scale {
        SHORT,
        LONG;

        public String getName(int exponent) {
            for (ScaleUnit unit : SCALE_UNITS) {
                if (unit.getExponent() == exponent) {
                    return unit.getName(this.ordinal());
                }
            }
            return ""; 
        }
    }

    /**
     * Change this scale to support American and modern British value (short scale)
     * or Traditional British value (long scale)
     */
    static public Scale SCALE = Scale.SHORT; 


    static abstract public class AbstractProcessor {

        static protected final String SEPARATOR = " ";
        static protected final int NO_VALUE = -1;

        protected List<Integer> getDigits(long value) {
            ArrayList<Integer> digits = new ArrayList<Integer>();
            if (value == 0) {
                digits.add(0);
            } else {
                while (value > 0) {
                    digits.add(0, (int) value % 10);
                    value /= 10;
                }
            }
            return digits;
        }

        public String getName(long value) {
            return getName(Long.toString(value));
        }

        public String getName(double value) {
            return getName(Double.toString(value));
        }

        abstract public String getName(String value);
    }

    static public class UnitProcessor extends AbstractProcessor {

        static private final String[] TOKENS = new String[] {
            "one", "two", "three", "four", "five", "six", "seven", "eight", "nine",
            "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"
        };

        @Override
        public String getName(String value) {
            StringBuilder buffer = new StringBuilder();

            int offset = NO_VALUE;
            int number;
            if (value.length() > 3) {
                number = Integer.valueOf(value.substring(value.length() - 3), 10);
            } else {
                number = Integer.valueOf(value, 10);
            }
            number %= 100;
            if (number < 10) {
                offset = (number % 10) - 1;
                //number /= 10;
            } else if (number < 20) {
                offset = (number % 20) - 1;
                //number /= 100;
            }

            if (offset != NO_VALUE && offset < TOKENS.length) {
                buffer.append(TOKENS[offset]);
            }

            return buffer.toString();
        }

    }

    static public class TensProcessor extends AbstractProcessor {

        static private final String[] TOKENS = new String[] {
            "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"
        };

        static private final String UNION_SEPARATOR = "-";

        private UnitProcessor unitProcessor = new UnitProcessor();

        @Override
        public String getName(String value) {
            StringBuilder buffer = new StringBuilder();
            boolean tensFound = false;

            int number;
            if (value.length() > 3) {
                number = Integer.valueOf(value.substring(value.length() - 3), 10);
            } else {
                number = Integer.valueOf(value, 10);
            }
            number %= 100;   // keep only two digits
            if (number >= 20) {
                buffer.append(TOKENS[(number / 10) - 2]);
                number %= 10;
                tensFound = true;
            } else {
                number %= 20;
            }

            if (number != 0) {
                if (tensFound) {
                    buffer.append(UNION_SEPARATOR);
                }
                buffer.append(unitProcessor.getName(number));
            }

            return buffer.toString();
        }
    }

    static public class HundredProcessor extends AbstractProcessor {

        private int EXPONENT = 2;

        private UnitProcessor unitProcessor = new UnitProcessor();
        private TensProcessor tensProcessor = new TensProcessor();

        @Override
        public String getName(String value) {
            StringBuilder buffer = new StringBuilder();

            int number;
            if (value.isEmpty()) {
                number = 0;
            } else if (value.length() > 4) {
                number = Integer.valueOf(value.substring(value.length() - 4), 10);
            } else {
                number = Integer.valueOf(value, 10);
            }
            number %= 1000;  // keep at least three digits

            if (number >= 100) {
                buffer.append(unitProcessor.getName(number / 100));
                buffer.append(SEPARATOR);
                buffer.append(SCALE.getName(EXPONENT));
            }

            String tensName = tensProcessor.getName(number % 100);

            if (!tensName.isEmpty() && (number >= 100)) {
                buffer.append(SEPARATOR);
            }
            buffer.append(tensName);

            return buffer.toString();
        }
    }

    static public class CompositeBigProcessor extends AbstractProcessor {

        private HundredProcessor hundredProcessor = new HundredProcessor();
        private AbstractProcessor lowProcessor;
        private int exponent;

        public CompositeBigProcessor(int exponent) {
            if (exponent <= 3) {
                lowProcessor = hundredProcessor;
            } else {
                lowProcessor = new CompositeBigProcessor(exponent - 3);
            }
            this.exponent = exponent;
        }

        public String getToken() {
            return SCALE.getName(getPartDivider());
        }

        protected AbstractProcessor getHighProcessor() {
            return hundredProcessor;
        }

        protected AbstractProcessor getLowProcessor() {
            return lowProcessor;
        }

        public int getPartDivider() {
            return exponent;
        }

        @Override
        public String getName(String value) {
            StringBuilder buffer = new StringBuilder();

            String high, low;
            if (value.length() < getPartDivider()) {
                high = "";
                low = value;
            } else {
                int index = value.length() - getPartDivider();
                high = value.substring(0, index);
                low = value.substring(index);
            }

            String highName = getHighProcessor().getName(high);
            String lowName = getLowProcessor().getName(low);

            if (!highName.isEmpty()) {
                buffer.append(highName);
                buffer.append(SEPARATOR);
                buffer.append(getToken());

                if (!lowName.isEmpty()) {
                    buffer.append(SEPARATOR);
                }
            }

            if (!lowName.isEmpty()) {
                buffer.append(lowName);
            }

            return buffer.toString();
        }
    }

    static public class DefaultProcessor extends AbstractProcessor {

        static private String MINUS = "minus";
        static private String UNION_AND = "and";

        static private String ZERO_TOKEN = "zero";

        private AbstractProcessor processor = new CompositeBigProcessor(63);

        @Override
        public String getName(String value) {
            boolean negative = false;
            if (value.startsWith("-")) {
                negative = true;
                value = value.substring(1);
            }

            int decimals = value.indexOf(".");
            String decimalValue = null;
            if (0 <= decimals) {
                decimalValue = value.substring(decimals + 1);
                value = value.substring(0, decimals);
            }

            String name = processor.getName(value);

            if (name.isEmpty()) {
                name = ZERO_TOKEN;
            } else if (negative) {
                name = MINUS.concat(SEPARATOR).concat(name); 
            }

            if (!(null == decimalValue || decimalValue.isEmpty())) {
                name = name.concat(SEPARATOR).concat(UNION_AND).concat(SEPARATOR)
                    .concat(processor.getName(decimalValue))
                    .concat(SEPARATOR).concat(SCALE.getName(-decimalValue.length()));
            }

            return name;
        }

    }

    static public AbstractProcessor processor;


    public static void main(String...args) {

        processor = new DefaultProcessor();

        long[] values = new long[] {
            0,
            4,
            10,
            12,
            100,
            108,
            299,
            1000,
            1003,
            2040,
            45213,
            100000,
            100005,
            100010,
            202020,
            202022,
            999999,
            1000000,
            1000001,
            10000000,
            10000007,
            99999999,
            Long.MAX_VALUE,
            Long.MIN_VALUE
        };

        String[] strValues = new String[] {
            "0001.2",
            "3.141592"
        };

        for (long val : values) {
            System.out.println(val + " = " + processor.getName(val) );
        }

        for (String strVal : strValues) {
            System.out.println(strVal + " = " + processor.getName(strVal) );
        }

        // generate a very big number...
        StringBuilder bigNumber = new StringBuilder();
        for (int d=0; d<66; d++) {
            bigNumber.append( (char) ((Math.random() * 10) + '0'));
        }
        bigNumber.append(".");
        for (int d=0; d<26; d++) {
            bigNumber.append( (char) ((Math.random() * 10) + '0'));
        }

        System.out.println(bigNumber.toString() + " = " + processor.getName(bigNumber.toString()));

    }

}

y un resultado de muestra (para el generador aleatorio de números grandes)

0 = zero
4 = four
10 = ten
12 = twelve
100 = one hundred
108 = one hundred eight
299 = two hundred ninety-nine
1000 = one thousand
1003 = one thousand three
2040 = two thousand fourty
45213 = fourty-five thousand two hundred thirteen
100000 = one hundred thousand
100005 = one hundred thousand five
100010 = one hundred thousand ten
202020 = two hundred two thousand twenty
202022 = two hundred two thousand twenty-two
999999 = nine hundred ninety-nine thousand nine hundred ninety-nine
1000000 = one million
1000001 = one million one
10000000 = ten million
10000007 = ten million seven
99999999 = ninety-nine million nine hundred ninety-nine thousand nine hundred ninety-nine
9223372036854775807 = nine quintillion two hundred twenty-three quadrillion three hundred seventy-two trillion thirty-six billion eight hundred fifty-four million seven hundred seventy-five thousand eight hundred seven
-9223372036854775808 = minus nine quintillion two hundred twenty-three quadrillion three hundred seventy-two trillion thirty-six billion eight hundred fifty-four million seven hundred seventy-five thousand eight hundred eight
0001.2 = one and two tenth
3.141592 = three and one hundred fourty-one thousand five hundred ninety-two millionth
694780458103427072928672912656674465845126458162617425283733729646.85695031739734695391404376 = six hundred ninety-four vigintillion seven hundred eighty novemdecillion four hundred fifty-eight octodecillion one hundred three septendecillion four hundred twenty-seven sexdecillion seventy-two quindecillion nine hundred twenty-eight quattuordecillion six hundred seventy-two tredecillion nine hundred twelve duodecillion six hundred fifty-six undecillion six hundred seventy-four decillion four hundred sixty-five nonillion eight hundred fourty-five octillion one hundred twenty-six septillion four hundred fifty-eight sextillion one hundred sixty-two quintillion six hundred seventeen quadrillion four hundred twenty-five trillion two hundred eighty-three billion seven hundred thirty-three million seven hundred twenty-nine thousand six hundred fourty-six and eighty-five septillion six hundred ninety-five sextillion thirty-one quintillion seven hundred thirty-nine quadrillion seven hundred thirty-four trillion six hundred ninety-five billion three hundred ninety-one million four hundred four thousand three hundred seventy-six hundred-septillionth

Oct 12 '2010 05:10 Yanick Rochon

Creo que esta solución no es la mejor, ya que sólo funciona para int, pero creo que es genial para un principiante.

public class NumberWordConverter {
    public static final String[] units = {
            "", "one", "two", "three", "four", "five", "six", "seven",
            "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen",
            "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"
    };

    public static final String[] tens = {
            "",        // 0
            "",        // 1
            "twenty",  // 2
            "thirty",  // 3
            "forty",   // 4
            "fifty",   // 5
            "sixty",   // 6
            "seventy", // 7
            "eighty",  // 8
            "ninety"   // 9
    };

    public static String convert(final int n) {
        if (n < 0) {
            return "minus " + convert(-n);
        }

        if (n < 20) {
            return units[n];
        }

        if (n < 100) {
            return tens[n / 10] + ((n % 10 != 0) ? " " : "") + units[n % 10];
        }

        if (n < 1000) {
            return units[n / 100] + " hundred" + ((n % 100 != 0) ? " " : "") + convert(n % 100);
        }

        if (n < 1000000) {
            return convert(n / 1000) + " thousand" + ((n % 1000 != 0) ? " " : "") + convert(n % 1000);
        }

        if (n < 1000000000) {
            return convert(n / 1000000) + " million" + ((n % 1000000 != 0) ? " " : "") + convert(n % 1000000);
        }

        return convert(n / 1000000000) + " billion"  + ((n % 1000000000 != 0) ? " " : "") + convert(n % 1000000000);
    }

    public static void main(final String[] args) {
        final Random generator = new Random();

        int n;
        for (int i = 0; i < 20; i++) {
            n = generator.nextInt(Integer.MAX_VALUE);

            System.out.printf("%10d = '%s'%n", n, convert(n));
        }

        n = 1000;
        System.out.printf("%10d = '%s'%n", n, convert(n));

        n = 2000;
        System.out.printf("%10d = '%s'%n", n, convert(n));

        n = 10000;
        System.out.printf("%10d = '%s'%n", n, convert(n));

        n = 11000;
        System.out.printf("%10d = '%s'%n", n, convert(n));

        n = 999999999;
        System.out.printf("%10d = '%s'%n", n, convert(n));

        n = Integer.MAX_VALUE;
        System.out.printf("%10d = '%s'%n", n, convert(n));
    }
}

La prueba crea 20 números aleatorios hasta Integer.MAX_VALUEalgunos que se sabe que son problemáticos, debido a 0, 10, etc. Salida:

   5599908 = 'five million five hundred ninety nine thousand nine hundred eight'
 192603486 = 'one hundred ninety two million six hundred three thousand four hundred eighty six'
1392431868 = 'one billion three hundred ninety two million four hundred thirty one thousand eight hundred sixty eight'
1023787010 = 'one billion twenty three million seven hundred eighty seven thousand ten'
1364396236 = 'one billion three hundred sixty four million three hundred ninety six thousand two hundred thirty six'
1511255671 = 'one billion five hundred eleven million two hundred fifty five thousand six hundred seventy one'
 225955221 = 'two hundred twenty five million nine hundred fifty five thousand two hundred twenty one'
1890141052 = 'one billion eight hundred ninety million one hundred forty one thousand fifty two'
 261839422 = 'two hundred sixty one million eight hundred thirty nine thousand four hundred twenty two'
 728428650 = 'seven hundred twenty eight million four hundred twenty eight thousand six hundred fifty'
 860607319 = 'eight hundred sixty million six hundred seven thousand three hundred nineteen'
 719753587 = 'seven hundred nineteen million seven hundred fifty three thousand five hundred eighty seven'
2063829124 = 'two billion sixty three million eight hundred twenty nine thousand one hundred twenty four'
1081010996 = 'one billion eighty one million ten thousand nine hundred ninety six'
 999215799 = 'nine hundred ninety nine million two hundred fifteen thousand seven hundred ninety nine'
2105226236 = 'two billion one hundred five million two hundred twenty six thousand two hundred thirty six'
1431882940 = 'one billion four hundred thirty one million eight hundred eighty two thousand nine hundred forty'
1991707241 = 'one billion nine hundred ninety one million seven hundred seven thousand two hundred forty one'
1088301563 = 'one billion eighty eight million three hundred one thousand five hundred sixty three'
 964601609 = 'nine hundred sixty four million six hundred one thousand six hundred nine'
      1000 = 'one thousand'
      2000 = 'two thousand'
     10000 = 'ten thousand'
     11000 = 'eleven thousand'
 999999999 = 'nine hundred ninety nine million nine hundred ninety nine thousand nine hundred ninety nine'
2147483647 = 'two billion one hundred forty seven million four hundred eighty three thousand six hundred forty seven'

Espero eso ayude :)

Sep 11 '2013 13:09 robosoul