in src/main/java/org/apache/commons/lang3/math/NumberUtils.java [650:818]
public static Number createNumber(final String str) {
if (str == null) {
return null;
}
if (StringUtils.isBlank(str)) {
throw new NumberFormatException("A blank string is not a valid number");
}
// Need to deal with all possible hex prefixes here
final String[] hex_prefixes = {"0x", "0X", "-0x", "-0X", "#", "-#"};
final int length = str.length();
int pfxLen = 0;
for (final String pfx : hex_prefixes) {
if (str.startsWith(pfx)) {
pfxLen += pfx.length();
break;
}
}
if (pfxLen > 0) { // we have a hex number
char firstSigDigit = 0; // strip leading zeroes
for (int i = pfxLen; i < length; i++) {
firstSigDigit = str.charAt(i);
if (firstSigDigit == '0') { // count leading zeroes
pfxLen++;
} else {
break;
}
}
final int hexDigits = length - pfxLen;
if (hexDigits > 16 || hexDigits == 16 && firstSigDigit > '7') { // too many for Long
return createBigInteger(str);
}
if (hexDigits > 8 || hexDigits == 8 && firstSigDigit > '7') { // too many for an int
return createLong(str);
}
return createInteger(str);
}
final char lastChar = str.charAt(length - 1);
String mant;
String dec;
String exp;
final int decPos = str.indexOf('.');
final int expPos = str.indexOf('e') + str.indexOf('E') + 1; // assumes both not present
// if both e and E are present, this is caught by the checks on expPos (which prevent IOOBE)
// and the parsing which will detect if e or E appear in a number due to using the wrong offset
if (decPos > -1) { // there is a decimal point
if (expPos > -1) { // there is an exponent
if (expPos < decPos || expPos > length) { // prevents double exponent causing IOOBE
throw new NumberFormatException(str + " is not a valid number.");
}
dec = str.substring(decPos + 1, expPos);
} else {
dec = str.substring(decPos + 1);
}
mant = getMantissa(str, decPos);
} else {
if (expPos > -1) {
if (expPos > length) { // prevents double exponent causing IOOBE
throw new NumberFormatException(str + " is not a valid number.");
}
mant = getMantissa(str, expPos);
} else {
mant = getMantissa(str);
}
dec = null;
}
if (!Character.isDigit(lastChar) && lastChar != '.') {
if (expPos > -1 && expPos < length - 1) {
exp = str.substring(expPos + 1, length - 1);
} else {
exp = null;
}
//Requesting a specific type..
final String numeric = str.substring(0, length - 1);
final boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
switch (lastChar) {
case 'l' :
case 'L' :
if (dec == null
&& exp == null
&& (!numeric.isEmpty() && numeric.charAt(0) == '-' && isDigits(numeric.substring(1)) || isDigits(numeric))) {
try {
return createLong(numeric);
} catch (final NumberFormatException nfe) { // NOPMD
// Too big for a long
}
return createBigInteger(numeric);
}
throw new NumberFormatException(str + " is not a valid number.");
case 'f' :
case 'F' :
try {
final Float f = createFloat(str);
if (!(f.isInfinite() || f.floatValue() == 0.0F && !allZeros)) {
//If it's too big for a float or the float value = 0 and the string
//has non-zeros in it, then float does not have the precision we want
return f;
}
} catch (final NumberFormatException nfe) { // NOPMD
// ignore the bad number
}
//$FALL-THROUGH$
case 'd' :
case 'D' :
try {
final Double d = createDouble(str);
if (!(d.isInfinite() || d.floatValue() == 0.0D && !allZeros)) {
return d;
}
} catch (final NumberFormatException nfe) { // NOPMD
// ignore the bad number
}
try {
return createBigDecimal(numeric);
} catch (final NumberFormatException e) { // NOPMD
// ignore the bad number
}
//$FALL-THROUGH$
default :
throw new NumberFormatException(str + " is not a valid number.");
}
}
//User doesn't have a preference on the return type, so let's start
//small and go from there...
if (expPos > -1 && expPos < length - 1) {
exp = str.substring(expPos + 1);
} else {
exp = null;
}
if (dec == null && exp == null) { // no decimal point and no exponent
//Must be an Integer, Long, Biginteger
try {
return createInteger(str);
} catch (final NumberFormatException nfe) { // NOPMD
// ignore the bad number
}
try {
return createLong(str);
} catch (final NumberFormatException nfe) { // NOPMD
// ignore the bad number
}
return createBigInteger(str);
}
//Must be a Float, Double, BigDecimal
final boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
try {
final Float f = createFloat(str);
final Double d = createDouble(str);
if (!f.isInfinite()
&& !(f.floatValue() == 0.0F && !allZeros)
&& f.toString().equals(d.toString())) {
return f;
}
if (!d.isInfinite() && !(d.doubleValue() == 0.0D && !allZeros)) {
final BigDecimal b = createBigDecimal(str);
if (b.compareTo(BigDecimal.valueOf(d.doubleValue())) == 0) {
return d;
}
return b;
}
} catch (final NumberFormatException nfe) { // NOPMD
// ignore the bad number
}
return createBigDecimal(str);
}