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java.lang.Objectcom.google.common.primitives.Chars
@GwtCompatible(emulated=true) public final class Chars
Static utility methods pertaining to char primitives, that are not
already found in either Character or Arrays.
All the operations in this class treat char values strictly
numerically; they are neither Unicode-aware nor locale-dependent.
| Field Summary | |
|---|---|
static int |
BYTES
The number of bytes required to represent a primitive char
value. |
| Method Summary | |
|---|---|
static List<Character> |
asList(char... backingArray)
Returns a fixed-size list backed by the specified array, similar to Arrays.asList(Object[]). |
static char |
checkedCast(long value)
Returns the char value that is equal to value, if possible. |
static int |
compare(char a,
char b)
Compares the two specified char values. |
static char[] |
concat(char[]... arrays)
Returns the values from each provided array combined into a single array. |
static boolean |
contains(char[] array,
char target)
Returns true if target is present as an element anywhere in
array. |
static char[] |
ensureCapacity(char[] array,
int minLength,
int padding)
Returns an array containing the same values as array, but
guaranteed to be of a specified minimum length. |
static char |
fromByteArray(byte[] bytes)
Returns the char value whose big-endian representation is
stored in the first 2 bytes of bytes; equivalent to ByteBuffer.wrap(bytes).getChar(). |
static char |
fromBytes(byte b1,
byte b2)
Returns the char value whose byte representation is the given 2
bytes, in big-endian order; equivalent to Chars.fromByteArray(new
byte[] {b1, b2}). |
static int |
hashCode(char value)
Returns a hash code for value; equal to the result of invoking
((Character) value).hashCode(). |
static int |
indexOf(char[] array,
char target)
Returns the index of the first appearance of the value target in
array. |
static int |
indexOf(char[] array,
char[] target)
Returns the start position of the first occurrence of the specified target within array, or -1 if there is no such occurrence. |
static String |
join(String separator,
char... array)
Returns a string containing the supplied char values separated
by separator. |
static int |
lastIndexOf(char[] array,
char target)
Returns the index of the last appearance of the value target in
array. |
static Comparator<char[]> |
lexicographicalComparator()
Returns a comparator that compares two char arrays
lexicographically. |
static char |
max(char... array)
Returns the greatest value present in array. |
static char |
min(char... array)
Returns the least value present in array. |
static char |
saturatedCast(long value)
Returns the char nearest in value to value. |
static char[] |
toArray(Collection<Character> collection)
Copies a collection of Character instances into a new array of
primitive char values. |
static byte[] |
toByteArray(char value)
Returns a big-endian representation of value in a 2-element byte
array; equivalent to ByteBuffer.allocate(2).putChar(value).array(). |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Field Detail |
|---|
public static final int BYTES
char
value.
| Method Detail |
|---|
public static int hashCode(char value)
value; equal to the result of invoking
((Character) value).hashCode().
value - a primitive char value
public static char checkedCast(long value)
char value that is equal to value, if possible.
value - any value in the range of the char type
char value that equals value
IllegalArgumentException - if value is greater than Character.MAX_VALUE or less than Character.MIN_VALUEpublic static char saturatedCast(long value)
char nearest in value to value.
value - any long value
char if it is in the range of the
char type, Character.MAX_VALUE if it is too large,
or Character.MIN_VALUE if it is too small
public static int compare(char a,
char b)
char values. The sign of the value
returned is the same as that of ((Character) a).compareTo(b).
a - the first char to compareb - the second char to compare
a is less than b; a positive
value if a is greater than b; or zero if they are equal
public static boolean contains(char[] array,
char target)
true if target is present as an element anywhere in
array.
array - an array of char values, possibly emptytarget - a primitive char value
true if array[i] == target for some value of i
public static int indexOf(char[] array,
char target)
target in
array.
array - an array of char values, possibly emptytarget - a primitive char value
i for which array[i] == target, or
-1 if no such index exists.
public static int indexOf(char[] array,
char[] target)
target within array, or -1 if there is no such occurrence.
More formally, returns the lowest index i such that java.util.Arrays.copyOfRange(array, i, i + target.length) contains exactly
the same elements as target.
array - the array to search for the sequence targettarget - the array to search for as a sub-sequence of array
public static int lastIndexOf(char[] array,
char target)
target in
array.
array - an array of char values, possibly emptytarget - a primitive char value
i for which array[i] == target,
or -1 if no such index exists.public static char min(char... array)
array.
array - a nonempty array of char values
array that is less than or equal to
every other value in the array
IllegalArgumentException - if array is emptypublic static char max(char... array)
array.
array - a nonempty array of char values
array that is greater than or equal to
every other value in the array
IllegalArgumentException - if array is emptypublic static char[] concat(char[]... arrays)
concat(new char[] {a, b}, new char[] {}, new
char[] {c} returns the array {a, b, c}.
arrays - zero or more char arrays
@GwtIncompatible(value="doesn\'t work") public static byte[] toByteArray(char value)
value in a 2-element byte
array; equivalent to ByteBuffer.allocate(2).putChar(value).array(). For example, the input
value '\\u5432' would yield the byte array {0x54, 0x32}.
If you need to convert and concatenate several values (possibly even of
different types), use a shared ByteBuffer instance, or use
ByteStreams.newDataOutput() to get a growable
buffer.
@GwtIncompatible(value="doesn\'t work") public static char fromByteArray(byte[] bytes)
char value whose big-endian representation is
stored in the first 2 bytes of bytes; equivalent to ByteBuffer.wrap(bytes).getChar(). For example, the input byte array
{0x54, 0x32} would yield the char value '\\u5432'.
Arguably, it's preferable to use ByteBuffer; that
library exposes much more flexibility at little cost in readability.
IllegalArgumentException - if bytes has fewer than 2
elements
@GwtIncompatible(value="doesn\'t work")
public static char fromBytes(byte b1,
byte b2)
char value whose byte representation is the given 2
bytes, in big-endian order; equivalent to Chars.fromByteArray(new
byte[] {b1, b2}).
public static char[] ensureCapacity(char[] array,
int minLength,
int padding)
array, but
guaranteed to be of a specified minimum length. If array already
has a length of at least minLength, it is returned directly.
Otherwise, a new array of size minLength + padding is returned,
containing the values of array, and zeroes in the remaining places.
array - the source arrayminLength - the minimum length the returned array must guaranteepadding - an extra amount to "grow" the array by if growth is
necessary
array, with guaranteed
minimum length minLength
IllegalArgumentException - if minLength or padding is
negative
public static String join(String separator,
char... array)
char values separated
by separator. For example, join("-", '1', '2', '3') returns
the string "1-2-3".
separator - the text that should appear between consecutive values in
the resulting string (but not at the start or end)array - an array of char values, possibly emptypublic static Comparator<char[]> lexicographicalComparator()
char arrays
lexicographically. That is, it compares, using compare(char, char)), the first pair of values that follow any
common prefix, or when one array is a prefix of the other, treats the
shorter array as the lesser. For example,
[] < ['a'] < ['a', 'b'] < ['b'].
The returned comparator is inconsistent with Object.equals(Object) (since arrays support only identity equality), but
it is consistent with Arrays.equals(char[], char[]).
public static char[] toArray(Collection<Character> collection)
Character instances into a new array of
primitive char values.
Elements are copied from the argument collection as if by collection.toArray(). Calling this method is as thread-safe as calling
that method.
collection - a collection of Character objects
collection, in the
same order, converted to primitives
NullPointerException - if collection or any of its elements
is nullpublic static List<Character> asList(char... backingArray)
Arrays.asList(Object[]). The list supports List.set(int, Object),
but any attempt to set a value to null will result in a NullPointerException.
The returned list maintains the values, but not the identities, of
Character objects written to or read from it. For example, whether
list.get(0) == list.get(0) is true for the returned list is
unspecified.
backingArray - the array to back the list
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