//  [java]
    public static Number createNumber(String str) throws NumberFormatException {
        if (str == null) {
            return null;
        }
        if (StringUtils.isBlank(str)) {
            throw new NumberFormatException("A blank string is not a valid number");
        }  
        if (str.startsWith("--")) {
            return null;
        }
        if (str.startsWith("0x") || str.startsWith("-0x") || str.startsWith("0X") || str.startsWith("-0X")) {
            return createInteger(str);
        }   
        char lastChar = str.charAt(str.length() - 1);
        String mant;
        String dec;
        String exp;
        int decPos = str.indexOf('.');
        int expPos = str.indexOf('e') + str.indexOf('E') + 1;
        if (decPos > -1) {
            if (expPos > -1) {
                if (expPos < decPos || expPos > str.length()) {
                    throw new NumberFormatException(str + " is not a valid number.");
                }
                dec = str.substring(decPos + 1, expPos);
            } else {
                dec = str.substring(decPos + 1);
            }
            mant = str.substring(0, decPos);
        } else {
            if (expPos > -1) {
                if (expPos > str.length()) {
                    throw new NumberFormatException(str + " is not a valid number.");
                }
                mant = str.substring(0, expPos);
            } else {
                mant = str;
            }
            dec = null;
        }
        if (!Character.isDigit(lastChar) && lastChar != '.') {
            if (expPos > -1 && expPos < str.length() - 1) {
                exp = str.substring(expPos + 1, str.length() - 1);
            } else {
                exp = null;
            }
            String numeric = str.substring(0, str.length() - 1);
            boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
            switch (lastChar) {
                case 'l' :
                case 'L' :
                    if (dec == null
                        && exp == null
                        && (numeric.charAt(0) == '-' && isDigits(numeric.substring(1)) || isDigits(numeric))) {
                        try {
                            return createLong(numeric);
                        } catch (NumberFormatException nfe) { 
                        }
                        return createBigInteger(numeric);
                    }
                    throw new NumberFormatException(str + " is not a valid number.");
                case 'f' :
                case 'F' :
                    try {
                        Float f = NumberUtils.createFloat(numeric);
                        if (!(f.isInfinite() || (f.floatValue() == 0.0F && !allZeros))) {
                            return f;
                        }
                    } catch (NumberFormatException nfe) { 
                    }
                case 'd' :
                case 'D' :
                    try {
                        Double d = NumberUtils.createDouble(numeric);
                        if (!(d.isInfinite() || (d.floatValue() == 0.0D && !allZeros))) {
                            return d;
                        }
                    } catch (NumberFormatException nfe) { 
                    }
                    try {
                        return createBigDecimal(numeric);
                    } catch (NumberFormatException e) { 
                    }
                default :
                    throw new NumberFormatException(str + " is not a valid number.");
            }
        } else {
            if (expPos > -1 && expPos < str.length() - 1) {
                exp = str.substring(expPos + 1, str.length());
            } else {
                exp = null;
            }
            if (dec == null && exp == null) {
                try {
                    return createInteger(str);
                } catch (NumberFormatException nfe) { 
                }
                try {
                    return createLong(str);
                } catch (NumberFormatException nfe) { 
                }
                return createBigInteger(str);
            } else {
                boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
                try {
                    Float f = createFloat(str);
                    if (!(f.isInfinite() || (f.floatValue() == 0.0F && !allZeros))) {
                        return f;
                    }
                } catch (NumberFormatException nfe) { 
                }
                try {
                    Double d = createDouble(str);
                    if (!(d.isInfinite() || (d.doubleValue() == 0.0D && !allZeros))) {
                        return d;
                    }
                } catch (NumberFormatException nfe) { 
                }
                return createBigDecimal(str);
            }
        }
    }