src/share/classes/java/lang/Long.java
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rev 10062 : 8041972: Add improved parse/format methods for Long/Integer
Contributed-by: redestad
@@ -24,10 +24,11 @@
*/
package java.lang;
import java.lang.annotation.Native;
+import static java.lang.Integer.requireNonEmpty;
import java.math.*;
/**
* The {@code Long} class wraps a value of the primitive type {@code
@@ -544,16 +545,80 @@
* the specified radix.
* @throws NumberFormatException if the string does not contain a
* parsable {@code long}.
*/
public static long parseLong(String s, int radix)
- throws NumberFormatException
- {
- if (s == null) {
- throw new NumberFormatException("null");
+ throws NumberFormatException {
+ requireNonEmpty(s);
+ return parseLong(s, radix, 0, s.length());
+ }
+
+ /**
+ * Parses the {@link CharSequence} argument as a signed {@code long} in
+ * the specified {@code radix}, beginning at the specified {@code beginIndex}
+ * and extending to the end of the sequence.
+ *
+ * <p>The method does not take steps to guard against the
+ * {@code CharSequence} being mutated while parsing.
+ *
+ * @param s the {@code CharSequence} containing the {@code long}
+ * representation to be parsed
+ * @param radix the radix to be used while parsing {@code s}.
+ * @param beginIndex the beginning index, inclusive.
+ * @return the signed {@code long} represented by the subsequence in
+ * the specified radix.
+ * @throws NullPointerException if {@code s} is null.
+ * @throws IllegalArgumentException if {@code beginIndex} is greater
+ * than or equal to {@code s.length()}.
+ * @throws IndexOutOfBoundsException if {@code beginIndex} is negative.
+ * @throws NumberFormatException if the {@code CharSequence} does not
+ * contain a parsable {@code long} in the specified
+ * {@code radix}, or if {@code radix} is either smaller than
+ * {@link java.lang.Character#MIN_RADIX} or larger than
+ * {@link java.lang.Character#MAX_RADIX}.
+ * @since 1.9
+ */
+ public static long parseLong(CharSequence s, int radix, int beginIndex)
+ throws NumberFormatException {
+ // forces a null check of s
+ return parseLong(s, radix, beginIndex, s.length());
}
+ /**
+ * Parses the {@link CharSequence} argument as a signed {@code long} in
+ * the specified {@code radix}, beginning at the specified
+ * {@code beginIndex} and extending to {@code endIndex - 1}.
+ *
+ * <p>The method does not take steps to guard against the
+ * {@code CharSequence} being mutated while parsing.
+ *
+ * @param s the {@code CharSequence} containing the {@code long}
+ * representation to be parsed
+ * @param radix the radix to be used while parsing {@code s}.
+ * @param beginIndex the beginning index, inclusive.
+ * @param endIndex the ending index, exclusive.
+ * @return the signed {@code long} represented by the subsequence in
+ * the specified radix.
+ * @throws NullPointerException if {@code s} is null.
+ * @throws IllegalArgumentException if {@code beginIndex} is greater
+ * than or equal to {@code endIndex}.
+ * @throws IndexOutOfBoundsException if {@code beginIndex} is
+ * negative, {@code endIndex} is negative or {@code endIndex}
+ * is greater than {@code s.length()}
+ * @throws NumberFormatException if the {@code CharSequence} does not
+ * contain a parsable {@code long} in the specified
+ * {@code radix}, or if {@code radix} is either smaller than
+ * {@link java.lang.Character#MIN_RADIX} or larger than
+ * {@link java.lang.Character#MAX_RADIX}.
+ * @since 1.9
+ */
+ public static long parseLong(CharSequence s, int radix, int beginIndex, int endIndex)
+ throws NumberFormatException {
+ s.getClass(); // null check
+ if (beginIndex >= endIndex) {
+ throw new IllegalArgumentException("beginIndex must be less than endIndex");
+ }
if (radix < Character.MIN_RADIX) {
throw new NumberFormatException("radix " + radix +
" less than Character.MIN_RADIX");
}
if (radix > Character.MAX_RADIX) {
@@ -561,47 +626,41 @@
" greater than Character.MAX_RADIX");
}
long result = 0;
boolean negative = false;
- int i = 0, len = s.length();
+ int i = beginIndex, end = endIndex;
long limit = -Long.MAX_VALUE;
long multmin;
int digit;
- if (len > 0) {
- char firstChar = s.charAt(0);
+ char firstChar = s.charAt(i);
if (firstChar < '0') { // Possible leading "+" or "-"
if (firstChar == '-') {
negative = true;
limit = Long.MIN_VALUE;
- } else if (firstChar != '+')
- throw NumberFormatException.forInputString(s);
-
- if (len == 1) // Cannot have lone "+" or "-"
- throw NumberFormatException.forInputString(s);
+ } else if (firstChar != '+') {
+ throw NumberFormatException.forInputString(s.toString());
+ }
i++;
+ if (end == i) { // Cannot have lone "+" or "-"
+ throw NumberFormatException.forInputString(s.toString());
+ }
}
multmin = limit / radix;
- while (i < len) {
+ while (i < end) {
// Accumulating negatively avoids surprises near MAX_VALUE
- digit = Character.digit(s.charAt(i++),radix);
- if (digit < 0) {
- throw NumberFormatException.forInputString(s);
- }
- if (result < multmin) {
- throw NumberFormatException.forInputString(s);
+ digit = Character.digit(s.charAt(i++), radix);
+ if (digit < 0 || result < multmin) {
+ throw NumberFormatException.forInputString(s.toString());
}
result *= radix;
if (result < limit + digit) {
- throw NumberFormatException.forInputString(s);
+ throw NumberFormatException.forInputString(s.toString());
}
result -= digit;
}
- } else {
- throw NumberFormatException.forInputString(s);
- }
return negative ? result : -result;
}
/**
* Parses the string argument as a signed decimal {@code long}.
@@ -626,11 +685,12 @@
* decimal.
* @throws NumberFormatException if the string does not contain a
* parsable {@code long}.
*/
public static long parseLong(String s) throws NumberFormatException {
- return parseLong(s, 10);
+ requireNonEmpty(s);
+ return parseLong(s, 10, 0, s.length());
}
/**
* Parses the string argument as an unsigned {@code long} in the
* radix specified by the second argument. An unsigned integer
@@ -674,32 +734,97 @@
* does not contain a parsable {@code long}.
* @since 1.8
*/
public static long parseUnsignedLong(String s, int radix)
throws NumberFormatException {
- if (s == null) {
- throw new NumberFormatException("null");
+ requireNonEmpty(s);
+ return parseUnsignedLong(s, radix, 0);
+ }
+
+ /**
+ * Parses the {@link CharSequence} argument as an unsigned {@code long} in
+ * the specified {@code radix}, beginning at the specified
+ * {@code beginIndex} and extending to the end of the sequence.
+ *
+ * <p>The method does not take steps to guard against the
+ * {@code CharSequence} being mutated while parsing.
+ *
+ * @param s the {@code CharSequence} containing the unsigned
+ * {@code long} representation to be parsed
+ * @param radix the radix to be used while parsing {@code s}.
+ * @param beginIndex the beginning index, inclusive.
+ * @return the unsigned {@code long} represented by the subsequence in
+ * the specified radix.
+ * @throws NullPointerException if {@code s} is null.
+ * @throws IllegalArgumentException if {@code beginIndex} is greater
+ * than or equal to {@code s.length()}.
+ * @throws IndexOutOfBoundsException if {@code beginIndex} is negative.
+ * @throws NumberFormatException if the {@code CharSequence} does not
+ * contain a parsable unsigned {@code long} in the specified
+ * {@code radix}, or if {@code radix} is either smaller than
+ * {@link java.lang.Character#MIN_RADIX} or larger than
+ * {@link java.lang.Character#MAX_RADIX}.
+ * @since 1.9
+ */
+ public static long parseUnsignedLong(CharSequence s, int radix, int beginIndex)
+ throws NumberFormatException {
+ // forces a null check of s
+ return parseUnsignedLong(s, radix, beginIndex, s.length());
}
- int len = s.length();
+ /**
+ * Parses the {@link CharSequence} argument as an unsigned {@code long} in
+ * the specified {@code radix}, beginning at the specified
+ * {@code beginIndex} and extending to {@code endIndex - 1}.
+ *
+ * <p>The method does not take steps to guard against the
+ * {@code CharSequence} being mutated while parsing.
+ *
+ * @param s the {@code CharSequence} containing the unsigned
+ * {@code long} representation to be parsed
+ * @param radix the radix to be used while parsing {@code s}.
+ * @param beginIndex the beginning index, inclusive.
+ * @param endIndex the ending index, exclusive.
+ * @return the unsigned {@code long} represented by the subsequence in
+ * the specified radix.
+ * @throws NullPointerException if {@code s} is null.
+ * @throws IllegalArgumentException if {@code beginIndex} is greater
+ * than or equal to {@code endIndex}.
+ * @throws IndexOutOfBoundsException if {@code beginIndex} is
+ * negative, {@code endIndex} is negative or {@code endIndex}
+ * is greater than {@code s.length()}
+ * @throws NumberFormatException if the {@code CharSequence} does not
+ * contain a parsable unsigned {@code long} in the specified
+ * {@code radix}, or if {@code radix} is either smaller than
+ * {@link java.lang.Character#MIN_RADIX} or larger than
+ * {@link java.lang.Character#MAX_RADIX}.
+ * @since 1.9
+ */
+ public static long parseUnsignedLong(CharSequence s, int radix, int beginIndex, int endIndex)
+ throws NumberFormatException {
+ s.getClass(); // null check
+ if (beginIndex >= endIndex) {
+ throw new IllegalArgumentException("beginIndex must be less than endIndex");
+ }
+ int start = beginIndex, len = endIndex - beginIndex;
if (len > 0) {
- char firstChar = s.charAt(0);
+ char firstChar = s.charAt(start);
if (firstChar == '-') {
- throw new
- NumberFormatException(String.format("Illegal leading minus sign " +
- "on unsigned string %s.", s));
+ throw new NumberFormatException(String.format("Illegal leading minus sign " +
+ "on unsigned string %s.", s.subSequence(start, start + len)));
} else {
if (len <= 12 || // Long.MAX_VALUE in Character.MAX_RADIX is 13 digits
(radix == 10 && len <= 18) ) { // Long.MAX_VALUE in base 10 is 19 digits
- return parseLong(s, radix);
+ return parseLong(s, radix, start, start + len);
}
- // No need for range checks on len due to testing above.
- long first = parseLong(s.substring(0, len - 1), radix);
- int second = Character.digit(s.charAt(len - 1), radix);
+ // No need for range checks on end due to testing above.
+ long first = parseLong(s, radix, start, start + len - 1);
+ int second = Character.digit(s.charAt(start + len - 1), radix);
if (second < 0) {
- throw new NumberFormatException("Bad digit at end of " + s);
+ throw new NumberFormatException("Bad digit at end of " +
+ s.subSequence(start, start + len));
}
long result = first * radix + second;
/*
* Test leftmost bits of multiprecision extension of first*radix
@@ -752,16 +877,16 @@
* upper bound is too small to overflow again after the
* signed long overflows to positive above 2^64 - 1. Hence
* result >= 0 implies overflow given C and D.
*/
throw new NumberFormatException(String.format("String value %s exceeds " +
- "range of unsigned long.", s));
+ "range of unsigned long.", s.subSequence(start, start + len)));
}
return result;
}
} else {
- throw NumberFormatException.forInputString(s);
+ throw NumberFormatException.forInputString("");
}
}
/**
* Parses the string argument as an unsigned decimal {@code long}. The
@@ -778,11 +903,12 @@
* @throws NumberFormatException if the string does not contain a
* parsable unsigned integer.
* @since 1.8
*/
public static long parseUnsignedLong(String s) throws NumberFormatException {
- return parseUnsignedLong(s, 10);
+ requireNonEmpty(s);
+ return parseUnsignedLong(s, 10, 0, s.length());
}
/**
* Returns a {@code Long} object holding the value
* extracted from the specified {@code String} when parsed
@@ -808,11 +934,12 @@
* radix.
* @throws NumberFormatException If the {@code String} does not
* contain a parsable {@code long}.
*/
public static Long valueOf(String s, int radix) throws NumberFormatException {
- return Long.valueOf(parseLong(s, radix));
+ requireNonEmpty(s);
+ return Long.valueOf(parseLong(s, radix, 0, s.length()));
}
/**
* Returns a {@code Long} object holding the value
* of the specified {@code String}. The argument is
@@ -833,13 +960,13 @@
* @return a {@code Long} object holding the value
* represented by the string argument.
* @throws NumberFormatException If the string cannot be parsed
* as a {@code long}.
*/
- public static Long valueOf(String s) throws NumberFormatException
- {
- return Long.valueOf(parseLong(s, 10));
+ public static Long valueOf(String s) throws NumberFormatException {
+ requireNonEmpty(s);
+ return Long.valueOf(parseLong(s, 10, 0, s.length()));
}
private static class LongCache {
private LongCache(){}
@@ -997,11 +1124,12 @@
* @throws NumberFormatException if the {@code String} does not
* contain a parsable {@code long}.
* @see java.lang.Long#parseLong(java.lang.String, int)
*/
public Long(String s) throws NumberFormatException {
- this.value = parseLong(s, 10);
+ requireNonEmpty(s);
+ this.value = parseLong(s, 10, 0, s.length());
}
/**
* Returns the value of this {@code Long} as a {@code byte} after
* a narrowing primitive conversion.