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java.lang.Object
com.ibm.icu.text.UTF16
public final class UTF16
extends Object
bounds()
.
Examples:
The following examples illustrate use of some of these methods.
// iteration forwards: Original for (int i = 0; i < s.length(); ++i) { char ch = s.charAt(i); doSomethingWith(ch); } // iteration forwards: Changes for UTF-32 int ch; for (int i = 0; i < s.length(); i+=UTF16.getCharCount(ch)) { ch = UTF16.charAt(s,i); doSomethingWith(ch); } // iteration backwards: Original for (int i = s.length() -1; i >= 0; --i) { char ch = s.charAt(i); doSomethingWith(ch); } // iteration backwards: Changes for UTF-32 int ch; for (int i = s.length() -1; i > 0; i-=UTF16.getCharCount(ch)) { ch = UTF16.charAt(s,i); doSomethingWith(ch); }Notes:
Lead
and Trail
in the API, which gives a better
sense of their ordering in a string. offset16
and
offset32
are used to distinguish offsets to UTF-16
boundaries vs offsets to UTF-32 boundaries. int char32
is
used to contain UTF-32 characters, as opposed to char16
,
which is a UTF-16 code unit.
bounds(string, offset16) != TRAIL
.
UCharacter.isLegal()
can be used to check
for validity if desired.
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public static final int CODEPOINT_MAX_VALUE
The highest Unicode code point value (scalar value) according to the Unicode Standard.
- Field Value:
- 1114111
public static final int CODEPOINT_MIN_VALUE
The lowest Unicode code point value.
- Field Value:
- 0
public static final int LEAD_SURROGATE_BOUNDARY
Value returned inbounds()
. These values are chosen specifically so that it actually represents the position of the character [offset16 - (value >> 2), offset16 + (value & 3)]
- Field Value:
- 2
public static final int LEAD_SURROGATE_MAX_VALUE
Lead surrogate maximum value
- Field Value:
- 56319
public static final int LEAD_SURROGATE_MIN_VALUE
Lead surrogate minimum value
- Field Value:
- 55296
public static final int SINGLE_CHAR_BOUNDARY
Value returned inbounds()
. These values are chosen specifically so that it actually represents the position of the character [offset16 - (value >> 2), offset16 + (value & 3)]
- Field Value:
- 1
public static final int SUPPLEMENTARY_MIN_VALUE
The minimum value for Supplementary code points
- Field Value:
- 65536
public static final int SURROGATE_MAX_VALUE
Maximum surrogate value
- Field Value:
- 57343
public static final int SURROGATE_MIN_VALUE
Surrogate minimum value
- Field Value:
- 55296
public static final int TRAIL_SURROGATE_BOUNDARY
Value returned inbounds()
. These values are chosen specifically so that it actually represents the position of the character [offset16 - (value >> 2), offset16 + (value & 3)]
- Field Value:
- 5
public static final int TRAIL_SURROGATE_MAX_VALUE
Trail surrogate maximum value
- Field Value:
- 57343
public static final int TRAIL_SURROGATE_MIN_VALUE
Trail surrogate minimum value
- Field Value:
- 56320
public static StringBuffer append(StringBuffer target, int char32)
Append a single UTF-32 value to the end of a StringBuffer. If a validity check is required, use isLegal() on char32 before calling.
- Parameters:
target
- the buffer to append tochar32
- value to append.
- Returns:
- the updated StringBuffer
public static int append(char[] target, int limit, int char32)
Adds a codepoint to offset16 position of the argument char array.
- Parameters:
target
- char array to be append with the new code pointlimit
- UTF16 offset which the codepoint will be appended.char32
- code point to be appended
- Returns:
- offset after char32 in the array.
public static StringBuffer appendCodePoint(StringBuffer target, int cp)
Cover JDK 1.5 APIs. Append the code point to the buffer and return the buffer as a convenience.
- Parameters:
target
- the buffer to append tocp
- the code point to append
- Returns:
- the updated StringBuffer
public static int bounds(String source, int offset16)
Returns the type of the boundaries around the char at offset16. Used for random access.
- Parameters:
source
- text to analyseoffset16
- UTF-16 offset
- Returns:
For bit-twiddlers, the return values for these are chosen so that the boundaries can be gotten by: [offset16 - (value >> 2), offset16 + (value & 3)].
- SINGLE_CHAR_BOUNDARY : a single char; the bounds are [offset16, offset16+1]
- LEAD_SURROGATE_BOUNDARY : a surrogate pair starting at offset16; the bounds are [offset16, offset16 + 2]
- TRAIL_SURROGATE_BOUNDARY : a surrogate pair starting at offset16 - 1; the bounds are [offset16 - 1, offset16 + 1]
public static int bounds(StringBuffer source, int offset16)
Returns the type of the boundaries around the char at offset16. Used for random access.
- Parameters:
source
- string buffer to analyseoffset16
- UTF16 offset
- Returns:
For bit-twiddlers, the return values for these are chosen so that the boundaries can be gotten by: [offset16 - (value >> 2), offset16 + (value & 3)].
- SINGLE_CHAR_BOUNDARY : a single char; the bounds are [offset16, offset16 + 1]
- LEAD_SURROGATE_BOUNDARY : a surrogate pair starting at offset16; the bounds are [offset16, offset16 + 2]
- TRAIL_SURROGATE_BOUNDARY : a surrogate pair starting at offset16 - 1; the bounds are [offset16 - 1, offset16 + 1]
public static int bounds(source[] , int start, int limit, int offset16)
Returns the type of the boundaries around the char at offset16. Used for random access. Note that the boundaries are determined with respect to the subarray, hence the char array {0xD800, 0xDC00} has the result SINGLE_CHAR_BOUNDARY for start = offset16 = 0 and limit = 1.
- Parameters:
start
- offset to substring in the source array for analyzinglimit
- offset to substring in the source array for analyzingoffset16
- UTF16 offset relative to start
- Returns:
For bit-twiddlers, the boundary values for these are chosen so that the boundaries can be gotten by: [offset16 - (boundvalue >> 2), offset16 + (boundvalue & 3)].
- SINGLE_CHAR_BOUNDARY : a single char; the bounds are
- LEAD_SURROGATE_BOUNDARY : a surrogate pair starting at offset16; the bounds are [offset16, offset16 + 2]
- TRAIL_SURROGATE_BOUNDARY : a surrogate pair starting at offset16 - 1; the bounds are [offset16 - 1, offset16 + 1]
public static int charAt(String source, int offset16)
Extract a single UTF-32 value from a string. Used when iterating forwards or backwards (withUTF16.getCharCount()
, as well as random access. If a validity check is required, useUCharacter.isLegal()
on the return value. If the char retrieved is part of a surrogate pair, its supplementary character will be returned. If a complete supplementary character is not found the incomplete character will be returned
- Parameters:
source
- array of UTF-16 charsoffset16
- UTF-16 offset to the start of the character.
- Returns:
- UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries of that codepoint are the same as in
bounds32()
.
public static int charAt(StringBuffer source, int offset16)
Extract a single UTF-32 value from a string. Used when iterating forwards or backwards (withUTF16.getCharCount()
, as well as random access. If a validity check is required, useUCharacter.isLegal()
on the return value. If the char retrieved is part of a surrogate pair, its supplementary character will be returned. If a complete supplementary character is not found the incomplete character will be returned
- Parameters:
source
- UTF-16 chars string bufferoffset16
- UTF-16 offset to the start of the character.
- Returns:
- UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries of that codepoint are the same as in
bounds32()
.
public static int charAt(Replaceable source, int offset16)
Extract a single UTF-32 value from a string. Used when iterating forwards or backwards (withUTF16.getCharCount()
, as well as random access. If a validity check is required, useUCharacter.isLegal()
on the return value. If the char retrieved is part of a surrogate pair, its supplementary character will be returned. If a complete supplementary character is not found the incomplete character will be returned
- Parameters:
source
- UTF-16 chars string bufferoffset16
- UTF-16 offset to the start of the character.
- Returns:
- UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries of that codepoint are the same as in
bounds32()
.
public static int charAt(source[] , int start, int limit, int offset16)
Extract a single UTF-32 value from a substring. Used when iterating forwards or backwards (withUTF16.getCharCount()
, as well as random access. If a validity check is required, useUCharacter.isLegal()
on the return value. If the char retrieved is part of a surrogate pair, its supplementary character will be returned. If a complete supplementary character is not found the incomplete character will be returned
- Parameters:
start
- offset to substring in the source array for analyzinglimit
- offset to substring in the source array for analyzingoffset16
- UTF-16 offset relative to start
- Returns:
- UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries of that codepoint are the same as in
bounds32()
.
public static int countCodePoint(String source)
Number of codepoints in a UTF16 String
- Parameters:
source
- UTF16 string
- Returns:
- number of codepoint in string
public static int countCodePoint(StringBuffer source)
Number of codepoints in a UTF16 String buffer
- Parameters:
source
- UTF16 string buffer
- Returns:
- number of codepoint in string
public static int countCodePoint(source[] , int start, int limit)
Number of codepoints in a UTF16 char array substring
- Parameters:
start
- offset of the substringlimit
- offset of the substring
- Returns:
- number of codepoint in the substring
public static StringBuffer delete(StringBuffer target, int offset16)
Removes the codepoint at the specified position in this target (shortening target by 1 character if the codepoint is a non-supplementary, 2 otherwise).
- Parameters:
target
- string buffer to remove codepoint fromoffset16
- offset which the codepoint will be removed
- Returns:
- a reference to target
public static int delete(target[] , int limit, int offset16)
Removes the codepoint at the specified position in this target (shortening target by 1 character if the codepoint is a non-supplementary, 2 otherwise).
- Parameters:
limit
- end index of the char array, limit <= target.lengthoffset16
- offset which the codepoint will be removed
- Returns:
- a new limit size
public static int findCodePointOffset(String source, int offset16)
Returns the UTF-32 offset corresponding to the first UTF-32 boundary at or after the given UTF-16 offset. Used for random access. See the class description for notes on roundtripping.
Note: If the UTF-16 offset is into the middle of a surrogate pair, then the UTF-32 offset of the lead of the pair is returned. To find the UTF-32 length of a string, use:len32 = countCodePoint(source, source.length());
- Parameters:
source
- text to analyseoffset16
- UTF-16 offset <32source text length.
- Returns:
- UTF-32 offset
public static int findCodePointOffset(StringBuffer source, int offset16)
Returns the UTF-32 offset corresponding to the first UTF-32 boundary at the given UTF-16 offset. Used for random access. See the class description for notes on roundtripping.
Note: If the UTF-16 offset is into the middle of a surrogate pair, then the UTF-32 offset of the lead of the pair is returned. To find the UTF-32 length of a string, use:len32 = countCodePoint(source);
- Parameters:
source
- text to analyseoffset16
- UTF-16 offset <32source text length.
- Returns:
- UTF-32 offset
public static int findCodePointOffset(source[] , int start, int limit, int offset16)
Returns the UTF-32 offset corresponding to the first UTF-32 boundary at the given UTF-16 offset. Used for random access. See the class description for notes on roundtripping.
Note: If the UTF-16 offset is into the middle of a surrogate pair, then the UTF-32 offset of the lead of the pair is returned. To find the UTF-32 length of a substring, use:len32 = countCodePoint(source, start, limit);
- Parameters:
start
- offset of the substringlimit
- offset of the substringoffset16
- UTF-16 relative to start
- Returns:
- UTF-32 offset relative to start
public static int findOffsetFromCodePoint(String source, int offset32)
Returns the UTF-16 offset that corresponds to a UTF-32 offset. Used for random access. See the class description for notes on roundtripping.
- Parameters:
source
- the UTF-16 stringoffset32
- UTF-32 offset
- Returns:
- UTF-16 offset
public static int findOffsetFromCodePoint(StringBuffer source, int offset32)
Returns the UTF-16 offset that corresponds to a UTF-32 offset. Used for random access. See the class description for notes on roundtripping.
- Parameters:
source
- the UTF-16 string bufferoffset32
- UTF-32 offset
- Returns:
- UTF-16 offset
public static int findOffsetFromCodePoint(source[] , int start, int limit, int offset32)
Returns the UTF-16 offset that corresponds to a UTF-32 offset. Used for random access. See the class description for notes on roundtripping.
- Parameters:
start
- offset of the substring to be analysedlimit
- offset of the substring to be analysedoffset32
- UTF-32 offset relative to start
- Returns:
- UTF-16 offset relative to start
public static int getCharCount(int char32)
Determines how many chars this char32 requires. If a validity check is required, useisLegal()
on char32 before calling.
- Parameters:
char32
- the input codepoint.
- Returns:
- 2 if is in supplementary space, otherwise 1.
public static char getLeadSurrogate(int char32)
Returns the lead surrogate. If a validity check is required, useisLegal()
on char32 before calling.
- Parameters:
char32
- the input character.
- Returns:
- lead surrogate if the getCharCount(ch) is 2;
and 0 otherwise (note: 0 is not a valid lead surrogate).
public static char getTrailSurrogate(int char32)
Returns the trail surrogate. If a validity check is required, useisLegal()
on char32 before calling.
- Parameters:
char32
- the input character.
- Returns:
- the trail surrogate if the getCharCount(ch) is 2;
otherwise the character itself
public static boolean hasMoreCodePointsThan(String source, int number)
Check if the string contains more Unicode code points than a certain number. This is more efficient than counting all code points in the entire string and comparing that number with a threshold. This function may not need to scan the string at all if the length is within a certain range, and never needs to count more than 'number + 1' code points. Logically equivalent to (countCodePoint(s) > number). A Unicode code point may occupy either one or two code units.
- Parameters:
source
- The input string.number
- The number of code points in the string is compared against the 'number' parameter.
- Returns:
- boolean value for whether the string contains more Unicode code points than 'number'.
public static boolean hasMoreCodePointsThan(StringBuffer source, int number)
Check if the string buffer contains more Unicode code points than a certain number. This is more efficient than counting all code points in the entire string buffer and comparing that number with a threshold. This function may not need to scan the string buffer at all if the length is within a certain range, and never needs to count more than 'number + 1' code points. Logically equivalent to (countCodePoint(s) > number). A Unicode code point may occupy either one or two code units.
- Parameters:
source
- The input string buffer.number
- The number of code points in the string buffer is compared against the 'number' parameter.
- Returns:
- boolean value for whether the string buffer contains more Unicode code points than 'number'.
public static boolean hasMoreCodePointsThan(source[] , int start, int limit, int number)
Check if the sub-range of char array, from argument start to limit, contains more Unicode code points than a certain number. This is more efficient than counting all code points in the entire char array range and comparing that number with a threshold. This function may not need to scan the char array at all if start and limit is within a certain range, and never needs to count more than 'number + 1' code points. Logically equivalent to (countCodePoint(source, start, limit) > number). A Unicode code point may occupy either one or two code units.
- Parameters:
start
- offset to substring in the source array for analyzinglimit
- offset to substring in the source array for analyzingnumber
- The number of code points in the string is compared against the 'number' parameter.
- Returns:
- boolean value for whether the string contains more Unicode code points than 'number'.
public static int indexOf(String source, String str)
Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument string str. This method is implemented based on codepoints, hence a "lead surrogate character + trail surrogate character" is treated as one entity.e Hence if the str starts with trail surrogate character at index 0, a source with a leading a surrogate character before str found at in source will not have a valid match. Vice versa for lead surrogates that ends str. See example below. If no such string str occurs in this source, then -1 is returned. Examples:
UTF16.indexOf("abc", "ab") returns 0
UTF16.indexOf("abc\ud800\udc00", "\ud800\udc00") returns 3
UTF16.indexOf("abc\ud800\udc00", "\ud800") returns -1
Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
- Parameters:
source
- UTF16 format Unicode string that will be searchedstr
- UTF16 format Unicode string to search for
- Returns:
- the index of the first occurrence of the codepoint in the argument Unicode string, or -1 if the codepoint does not occur.
public static int indexOf(String source, String str, int fromIndex)
Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument string str. This method is implemented based on codepoints, hence a "lead surrogate character + trail surrogate character" is treated as one entity.e Hence if the str starts with trail surrogate character at index 0, a source with a leading a surrogate character before str found at in source will not have a valid match. Vice versa for lead surrogates that ends str. See example below. If no such string str occurs in this source, then -1 is returned. Examples:
UTF16.indexOf("abc", "ab", 0) returns 0
UTF16.indexOf("abc\ud800\udc00", "\ud800\udc00", 0) returns 3
UTF16.indexOf("abc\ud800\udc00", "\ud800\udc00", 2) returns 3
UTF16.indexOf("abc\ud800\udc00", "\ud800", 0) returns -1
Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
- Parameters:
source
- UTF16 format Unicode string that will be searchedstr
- UTF16 format Unicode string to search forfromIndex
- the index to start the search from.
- Returns:
- the index of the first occurrence of the codepoint in the argument Unicode string, or -1 if the codepoint does not occur.
public static int indexOf(String source, int char32)
Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument codepoint. I.e., the smallest indexi
such thatUTF16.charAt(source, i) == char32
is true. If no such character occurs in this string, then -1 is returned. Examples:
UTF16.indexOf("abc", 'a') returns 0
UTF16.indexOf("abc\ud800\udc00", 0x10000) returns 3
UTF16.indexOf("abc\ud800\udc00", 0xd800) returns -1
Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
- Parameters:
source
- UTF16 format Unicode string that will be searchedchar32
- codepoint to search for
- Returns:
- the index of the first occurrence of the codepoint in the argument Unicode string, or -1 if the codepoint does not occur.
public static int indexOf(String source, int char32, int fromIndex)
Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument codepoint. I.e., the smallest index i such that:
(UTF16.charAt(source, i) == char32 && i >= fromIndex) is true. If no such character occurs in this string, then -1 is returned. Examples:
UTF16.indexOf("abc", 'a', 1) returns -1
UTF16.indexOf("abc\ud800\udc00", 0x10000, 1) returns 3
UTF16.indexOf("abc\ud800\udc00", 0xd800, 1) returns -1
Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
- Parameters:
source
- UTF16 format Unicode string that will be searchedchar32
- codepoint to search forfromIndex
- the index to start the search from.
- Returns:
- the index of the first occurrence of the codepoint in the argument Unicode string at or after fromIndex, or -1 if the codepoint does not occur.
public static StringBuffer insert(StringBuffer target, int offset16, int char32)
Inserts char32 codepoint into target at the argument offset16. If the offset16 is in the middle of a supplementary codepoint, char32 will be inserted after the supplementary codepoint. The length of target increases by one if codepoint is non-supplementary, 2 otherwise. The overall effect is exactly as if the argument were converted to a string by the method valueOf(char) and the characters in that string were then inserted into target at the position indicated by offset16. The offset argument must be greater than or equal to 0, and less than or equal to the length of source.
- Parameters:
target
- string buffer to insert tooffset16
- offset which char32 will be inserted inchar32
- codepoint to be inserted
- Returns:
- a reference to target
public static int insert(target[] , int limit, int offset16, int char32)
Inserts char32 codepoint into target at the argument offset16. If the offset16 is in the middle of a supplementary codepoint, char32 will be inserted after the supplementary codepoint. Limit increases by one if codepoint is non-supplementary, 2 otherwise. The overall effect is exactly as if the argument were converted to a string by the method valueOf(char) and the characters in that string were then inserted into target at the position indicated by offset16. The offset argument must be greater than or equal to 0, and less than or equal to the limit.
- Parameters:
limit
- end index of the char array, limit <= target.lengthoffset16
- offset which char32 will be inserted inchar32
- codepoint to be inserted
- Returns:
- new limit size
public static boolean isLeadSurrogate(char char16)
Determines whether the character is a lead surrogate.
- Parameters:
char16
- the input character.
- Returns:
- true iff the input character is a lead surrogate
public static boolean isSurrogate(char char16)
Determines whether the code value is a surrogate.
- Parameters:
char16
- the input character.
- Returns:
- true iff the input character is a surrogate.
public static boolean isTrailSurrogate(char char16)
Determines whether the character is a trail surrogate.
- Parameters:
char16
- the input character.
- Returns:
- true iff the input character is a trail surrogate.
public static int lastIndexOf(String source, String str)
Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument string str. This method is implemented based on codepoints, hence a "lead surrogate character + trail surrogate character" is treated as one entity.e Hence if the str starts with trail surrogate character at index 0, a source with a leading a surrogate character before str found at in source will not have a valid match. Vice versa for lead surrogates that ends str. See example below. Examples:
UTF16.lastIndexOf("abc", "a") returns 0
UTF16.lastIndexOf("abc\ud800\udc00", "\ud800\udc00") returns 3
UTF16.lastIndexOf("abc\ud800\udc00", "\ud800") returns -1
source is searched backwards starting at the last character. Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
- Parameters:
source
- UTF16 format Unicode string that will be searchedstr
- UTF16 format Unicode string to search for
- Returns:
- the index of the last occurrence of the codepoint in source, or -1 if the codepoint does not occur.
public static int lastIndexOf(String source, String str, int fromIndex)
Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument string str, where the result is less than or equals to fromIndex. This method is implemented based on codepoints, hence a "lead surrogate character + trail surrogate character" is treated as one entity. Hence if the str starts with trail surrogate character at index 0, a source with a leading a surrogate character before str found at in source will not have a valid match. Vice versa for lead surrogates that ends str. See example below. Examples:
UTF16.lastIndexOf("abc", "c", 2) returns 2
UTF16.lastIndexOf("abc", "c", 1) returns -1
UTF16.lastIndexOf("abc\ud800\udc00", "\ud800\udc00", 5) returns 3
UTF16.lastIndexOf("abc\ud800\udc00", "\ud800\udc00", 3) returns 3
UTF16.lastIndexOf("abc\ud800\udc00", "\ud800", 4) returns -1
source is searched backwards starting at the last character. Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
- Parameters:
source
- UTF16 format Unicode string that will be searchedstr
- UTF16 format Unicode string to search forfromIndex
- the index to start the search from. There is no restriction on the value of fromIndex. If it is greater than or equal to the length of this string, it has the same effect as if it were equal to one less than the length of this string: this entire string may be searched. If it is negative, it has the same effect as if it were -1: -1 is returned.
- Returns:
- the index of the last occurrence of the codepoint in source, or -1 if the codepoint does not occur.
public static int lastIndexOf(String source, int char32)
Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument codepoint. I.e., the index returned is the largest value i such that: UTF16.charAt(source, i) == char32 is true. Examples:
UTF16.lastIndexOf("abc", 'a') returns 0
UTF16.lastIndexOf("abc\ud800\udc00", 0x10000) returns 3
UTF16.lastIndexOf("abc\ud800\udc00", 0xd800) returns -1
source is searched backwards starting at the last character. Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
- Parameters:
source
- UTF16 format Unicode string that will be searchedchar32
- codepoint to search for
- Returns:
- the index of the last occurrence of the codepoint in source, or -1 if the codepoint does not occur.
public static int lastIndexOf(String source, int char32, int fromIndex)
Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument codepoint, where the result is less than or equals to fromIndex. This method is implemented based on codepoints, hence a single surrogate character will not match a supplementary character. source is searched backwards starting at the last character starting at the specified index. Examples:
UTF16.lastIndexOf("abc", 'c', 2) returns 2
UTF16.lastIndexOf("abc", 'c', 1) returns -1
UTF16.lastIndexOf("abc\ud800\udc00", 0x10000, 5) returns 3
UTF16.lastIndexOf("abc\ud800\udc00", 0x10000, 3) returns 3
UTF16.lastIndexOf("abc\ud800\udc00", 0xd800) returns -1
Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
- Parameters:
source
- UTF16 format Unicode string that will be searchedchar32
- codepoint to search forfromIndex
- the index to start the search from. There is no restriction on the value of fromIndex. If it is greater than or equal to the length of this string, it has the same effect as if it were equal to one less than the length of this string: this entire string may be searched. If it is negative, it has the same effect as if it were -1: -1 is returned.
- Returns:
- the index of the last occurrence of the codepoint in source, or -1 if the codepoint does not occur.
public static int moveCodePointOffset(String source, int offset16, int shift32)
Shifts offset16 by the argument number of codepoints
- Parameters:
source
- stringoffset16
- UTF16 position to shiftshift32
- number of codepoints to shift
- Returns:
- new shifted offset16
public static int moveCodePointOffset(StringBuffer source, int offset16, int shift32)
Shifts offset16 by the argument number of codepoints
- Parameters:
source
- string bufferoffset16
- UTF16 position to shiftshift32
- number of codepoints to shift
- Returns:
- new shifted offset16
public static int moveCodePointOffset(source[] , int start, int limit, int offset16, int shift32)
Shifts offset16 by the argument number of codepoints within a subarray.
- Parameters:
start
- position of the subarray to be performed onlimit
- position of the subarray to be performed onoffset16
- UTF16 position to shift relative to startshift32
- number of codepoints to shift
- Returns:
- new shifted offset16 relative to start
public static String newString(int[] codePoints, int offset, int count)
Cover JDK 1.5 API. Create a String from an array of codePoints.
- Parameters:
codePoints
- the code arrayoffset
- the start of the text in the code point arraycount
- the number of code points
- Returns:
- a String representing the code points between offset and count
public static String replace(String source, String oldStr, String newStr)
Returns a new UTF16 format Unicode string resulting from replacing all occurrences of oldStr in source with newStr. If the string oldStr does not occur in the UTF16 format Unicode string source, then source will be returned. Otherwise, a new String object is created that represents a codepoint sequence identical to the codepoint sequence represented by source, except that every occurrence of oldStr is replaced by an occurrence of newStr. Examples:
UTF16.replace("mesquite in your cellar", "e", "o");
returns "mosquito in your collar"
UTF16.replace("mesquite in your cellar", "mesquite", "cat");
returns "cat in your cellar"
UTF16.replace("JonL", "q", "x");
returns "JonL" (no change)
UTF16.replace("Supplementary character \ud800\udc00", "\ud800\udc00", '!');
returns "Supplementary character !"
UTF16.replace("Supplementary character \ud800\udc00", "\ud800", '!');
returns "Supplementary character \ud800\udc00"
Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
- Parameters:
source
- UTF16 format Unicode string which the replacements will be based on.oldStr
- non-zero-length string to be replaced.newStr
- the new string to replace oldStr
- Returns:
- new String derived from source by replacing every occurrence of oldStr with newStr. When no oldStr is found in source, then source will be returned.
public static String replace(String source, int oldChar32, int newChar32)
Returns a new UTF16 format Unicode string resulting from replacing all occurrences of oldChar32 in source with newChar32. If the character oldChar32 does not occur in the UTF16 format Unicode string source, then source will be returned. Otherwise, a new String object is created that represents a codepoint sequence identical to the codepoint sequence represented by source, except that every occurrence of oldChar32 is replaced by an occurrence of newChar32. Examples:
UTF16.replace("mesquite in your cellar", 'e', 'o');
returns "mosquito in your collar"
UTF16.replace("JonL", 'q', 'x');
returns "JonL" (no change)
UTF16.replace("Supplementary character \ud800\udc00", 0x10000, '!');
returns "Supplementary character !"
UTF16.replace("Supplementary character \ud800\udc00", 0xd800, '!');
returns "Supplementary character \ud800\udc00"
Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
- Parameters:
source
- UTF16 format Unicode string which the codepoint replacements will be based on.oldChar32
- non-zero old codepoint to be replaced.newChar32
- the new codepoint to replace oldChar32
- Returns:
- new String derived from source by replacing every occurrence of oldChar32 with newChar32, unless when no oldChar32 is found in source then source will be returned.
public static StringBuffer reverse(StringBuffer source)
Reverses a UTF16 format Unicode string and replaces source's content with it. This method will reverse surrogate characters correctly, instead of blindly reversing every character. Examples:
UTF16.reverse(new StringBuffer( "Supplementary characters \ud800\udc00\ud801\udc01"))
returns "\ud801\udc01\ud800\udc00 sretcarahc yratnemelppuS".
- Parameters:
source
- the source StringBuffer that contains UTF16 format Unicode string to be reversed
- Returns:
- a modified source with reversed UTF16 format Unicode string.
public static void setCharAt(StringBuffer target, int offset16, int char32)
Set a code point into a UTF16 position. Adjusts target according if we are replacing a non-supplementary codepoint with a supplementary and vice versa.
- Parameters:
target
- stringbufferoffset16
- UTF16 position to insert intochar32
- code point
public static int setCharAt(target[] , int limit, int offset16, int char32)
Set a code point into a UTF16 position in a char array. Adjusts target according if we are replacing a non-supplementary codepoint with a supplementary and vice versa.
- Parameters:
limit
- numbers of valid chars in target, different from target.length. limit counts the number of chars in target that represents a string, not the size of array target.offset16
- UTF16 position to insert intochar32
- code point
- Returns:
- new number of chars in target that represents a string
public static String valueOf(String source, int offset16)
Convenience method corresponding to String.valueOf(codepoint at offset16). Returns a one or two char string containing the UTF-32 value in UTF16 format. If offset16 indexes a surrogate character, the whole supplementary codepoint will be returned. If a validity check is required, use isLegal() on the codepoint at offset16 before calling. The result returned will be a newly created String obtained by calling source.substring(..) with the appropriate indexes.
- Parameters:
source
- the input string.offset16
- the UTF16 index to the codepoint in source
- Returns:
- string value of char32 in UTF16 format
public static String valueOf(StringBuffer source, int offset16)
Convenience method corresponding to StringBuffer.valueOf(codepoint at offset16). Returns a one or two char string containing the UTF-32 value in UTF16 format. If offset16 indexes a surrogate character, the whole supplementary codepoint will be returned. If a validity check is required, use isLegal() on the codepoint at offset16 before calling. The result returned will be a newly created String obtained by calling source.substring(..) with the appropriate indexes.
- Parameters:
source
- the input string buffer.offset16
- the UTF16 index to the codepoint in source
- Returns:
- string value of char32 in UTF16 format
public static String valueOf(int char32)
Convenience method corresponding to String.valueOf(char). Returns a one or two char string containing the UTF-32 value in UTF16 format. If a validity check is required, use isLegal() on char32 before calling.
- Parameters:
char32
- the input character.
- Returns:
- string value of char32 in UTF16 format
public static String valueOf(source[] , int start, int limit, int offset16)
Convenience method. Returns a one or two char string containing the UTF-32 value in UTF16 format. If offset16 indexes a surrogate character, the whole supplementary codepoint will be returned, except when either the leading or trailing surrogate character lies out of the specified subarray. In the latter case, only the surrogate character within bounds will be returned. If a validity check is required, use isLegal() on the codepoint at offset16 before calling. The result returned will be a newly created String containing the relevant characters.
- Parameters:
start
- start index of the subarraylimit
- end index of the subarrayoffset16
- the UTF16 index to the codepoint in source relative to start
- Returns:
- string value of char32 in UTF16 format