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//##header J2SE15 /** ******************************************************************************* * Copyright (C) 1996-2007, International Business Machines Corporation and * * others. All Rights Reserved. * ******************************************************************************* */ /* * File: UTF16.java * ************************************************************************ * * ADOBE CONFIDENTIAL * ___________________ * * Copyright 2012 Adobe Systems Incorporated * All Rights Reserved. * * NOTICE: All information contained herein is, and remains * the property of Adobe Systems Incorporated and its suppliers, * if any. The intellectual and technical concepts contained * herein are proprietary to Adobe Systems Incorporated and its * suppliers and are protected by trade secret or copyright law. * Dissemination of this information or reproduction of this material * is strictly forbidden unless prior written permission is obtained * from Adobe Systems Incorporated. **************************************************************************/ package com.adobe.agl.text; import com.adobe.agl.impl.UCharacterProperty; /** *on char32 before calling. * * @param char32 * the input character. * @return string value of char32 in UTF16 format * @exception IllegalArgumentException * thrown if char32 is a invalid codepoint. * @stable ICU 2.1 */ public static String valueOf(int char32) { if (char32 < CODEPOINT_MIN_VALUE || char32 > CODEPOINT_MAX_VALUE) { throw new IllegalArgumentException("Illegal codepoint"); } return toString(char32); } /** * 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. * * @param source * the input string. * @param offset16 * the UTF16 index to the codepoint in source * @return string value of char32 in UTF16 format * @stable ICU 2.1 */ public static String valueOf(String source, int offset16) { switch (bounds(source, offset16)) { case LEAD_SURROGATE_BOUNDARY: return source.substring(offset16, offset16 + 2); case TRAIL_SURROGATE_BOUNDARY: return source.substring(offset16 - 1, offset16 + 1); default: return source.substring(offset16, offset16 + 1); } } /** * 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. * * @param source * the input string buffer. * @param offset16 * the UTF16 index to the codepoint in source * @return string value of char32 in UTF16 format * @stable ICU 2.1 */ public static String valueOf(StringBuffer source, int offset16) { switch (bounds(source, offset16)) { case LEAD_SURROGATE_BOUNDARY: return source.substring(offset16, offset16 + 2); case TRAIL_SURROGATE_BOUNDARY: return source.substring(offset16 - 1, offset16 + 1); default: return source.substring(offset16, offset16 + 1); } } /** * 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. * * @param source * the input char array. * @param start * start index of the subarray * @param limit * end index of the subarray * @param offset16 * the UTF16 index to the codepoint in source relative to start * @return string value of char32 in UTF16 format * @stable ICU 2.1 */ public static String valueOf(char source[], int start, int limit, int offset16) { switch (bounds(source, start, limit, offset16)) { case LEAD_SURROGATE_BOUNDARY: return new String(source, start + offset16, 2); case TRAIL_SURROGATE_BOUNDARY: return new String(source, start + offset16 - 1, 2); } return new String(source, start + offset16, 1); } /** * Returns the UTF-16 offset that corresponds to a UTF-32 offset. Used for random access. See * the class description for notes on roundtripping. * * @param source * the UTF-16 string * @param offset32 * UTF-32 offset * @return UTF-16 offset * @exception IndexOutOfBoundsException * if offset32 is out of bounds. * @stable ICU 2.1 */ public static int findOffsetFromCodePoint(String source, int offset32) { char ch; int size = source.length(), result = 0, count = offset32; if (offset32 < 0 || offset32 > size) { throw new StringIndexOutOfBoundsException(offset32); } while (result < size && count > 0) { ch = source.charAt(result); if (isLeadSurrogate(ch) && ((result + 1) < size) && isTrailSurrogate(source.charAt(result + 1))) { result++; } count--; result++; } if (count != 0) { throw new StringIndexOutOfBoundsException(offset32); } return result; } /** * Returns the UTF-16 offset that corresponds to a UTF-32 offset. Used for random access. See * the class description for notes on roundtripping. * * @param source * the UTF-16 string buffer * @param offset32 * UTF-32 offset * @return UTF-16 offset * @exception IndexOutOfBoundsException * if offset32 is out of bounds. * @stable ICU 2.1 */ public static int findOffsetFromCodePoint(StringBuffer source, int offset32) { char ch; int size = source.length(), result = 0, count = offset32; if (offset32 < 0 || offset32 > size) { throw new StringIndexOutOfBoundsException(offset32); } while (result < size && count > 0) { ch = source.charAt(result); if (isLeadSurrogate(ch) && ((result + 1) < size) && isTrailSurrogate(source.charAt(result + 1))) { result++; } count--; result++; } if (count != 0) { throw new StringIndexOutOfBoundsException(offset32); } return result; } /** * Returns the UTF-16 offset that corresponds to a UTF-32 offset. Used for random access. See * the class description for notes on roundtripping. * * @param source * the UTF-16 char array whose substring is to be analysed * @param start * offset of the substring to be analysed * @param limit * offset of the substring to be analysed * @param offset32 * UTF-32 offset relative to start * @return UTF-16 offset relative to start * @exception IndexOutOfBoundsException * if offset32 is out of bounds. * @stable ICU 2.1 */ public static int findOffsetFromCodePoint(char source[], int start, int limit, int offset32) { char ch; int result = start, count = offset32; if (offset32 > limit - start) { throw new ArrayIndexOutOfBoundsException(offset32); } while (result < limit && count > 0) { ch = source[result]; if (isLeadSurrogate(ch) && ((result + 1) < limit) && isTrailSurrogate(source[result + 1])) { result++; } count--; result++; } if (count != 0) { throw new ArrayIndexOutOfBoundsException(offset32); } return result - start; } /** * 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.* Standalone utility class providing UTF16 character conversions and indexing conversions. *
** Code that uses strings alone rarely need modification. By design, UTF-16 does not allow overlap, * so searching for strings is a safe operation. Similarly, concatenation is always safe. * Substringing is safe if the start and end are both on UTF-32 boundaries. In normal code, the * values for start and end are on those boundaries, since they arose from operations like * searching. If not, the nearest UTF-32 boundaries can be determined using
* Examples: *bounds(). ** 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: **
* * @author Mark Davis, with help from Markus Scherer * @stable ICU 2.1 */ public final class UTF16 { // public variables --------------------------------------------------- /** * Value returned in- Naming: For clarity, High and Low surrogates are called
*Lead* andTrailin the API, which gives a better sense of their ordering in a string. *offset16andoffset32are used to distinguish offsets to UTF-16 * boundaries vs offsets to UTF-32 boundaries.int char32is used to contain UTF-32 * characters, as opposed tochar16, which is a UTF-16 code unit.- Roundtripping Offsets: You can always roundtrip from a UTF-32 offset to a * UTF-16 offset and back. Because of the difference in structure, you can roundtrip from a UTF-16 * offset to a UTF-32 offset and back if and only if
*bounds(string, offset16) != TRAIL. *- Exceptions: The error checking will throw an exception if indices are out * of bounds. Other than than that, all methods will behave reasonably, even if unmatched surrogates * or out-of-bounds UTF-32 values are present.
*UCharacter.isLegal()can be used to * check for validity if desired.- Unmatched Surrogates: If the string contains unmatched surrogates, then * these are counted as one UTF-32 value. This matches their iteration behavior, which is vital. It * also matches common display practice as missing glyphs (see the Unicode Standard Section 5.4, * 5.5).
*- Optimization: The method implementations may need optimization if the * compiler doesn't fold static final methods. Since surrogate pairs will form an exceeding small * percentage of all the text in the world, the singleton case should always be optimized for.
** bounds(). * These values are chosen specifically so that it actually represents the position of the * character [offset16 - (value >> 2), offset16 + (value & 3)] * * @stable ICU 2.1 */ public static final int SINGLE_CHAR_BOUNDARY = 1, LEAD_SURROGATE_BOUNDARY = 2, TRAIL_SURROGATE_BOUNDARY = 5; /** * The lowest Unicode code point value. * * @stable ICU 2.1 */ public static final int CODEPOINT_MIN_VALUE = 0; /** * The highest Unicode code point value (scalar value) according to the Unicode Standard. * * @stable ICU 2.1 */ public static final int CODEPOINT_MAX_VALUE = 0x10ffff; /** * The minimum value for Supplementary code points * * @stable ICU 2.1 */ public static final int SUPPLEMENTARY_MIN_VALUE = 0x10000; /** * Lead surrogate minimum value * * @stable ICU 2.1 */ public static final int LEAD_SURROGATE_MIN_VALUE = 0xD800; /** * Trail surrogate minimum value * * @stable ICU 2.1 */ public static final int TRAIL_SURROGATE_MIN_VALUE = 0xDC00; /** * Lead surrogate maximum value * * @stable ICU 2.1 */ public static final int LEAD_SURROGATE_MAX_VALUE = 0xDBFF; /** * Trail surrogate maximum value * * @stable ICU 2.1 */ public static final int TRAIL_SURROGATE_MAX_VALUE = 0xDFFF; /** * Surrogate minimum value * * @stable ICU 2.1 */ public static final int SURROGATE_MIN_VALUE = LEAD_SURROGATE_MIN_VALUE; /** * Maximum surrogate value * * @stable ICU 2.1 */ public static final int SURROGATE_MAX_VALUE = TRAIL_SURROGATE_MAX_VALUE; /** * Lead surrogate bitmask */ private static final int LEAD_SURROGATE_BITMASK = 0xFFFFFC00; /** * Trail surrogate bitmask */ private static final int TRAIL_SURROGATE_BITMASK = 0xFFFFFC00; /** * Surrogate bitmask */ private static final int SURROGATE_BITMASK = 0xFFFFF800; /** * Lead surrogate bits */ private static final int LEAD_SURROGATE_BITS = 0xD800; /** * Trail surrogate bits */ private static final int TRAIL_SURROGATE_BITS = 0xDC00; /** * Surrogate bits */ private static final int SURROGATE_BITS = 0xD800; // constructor -------------------------------------------------------- // /CLOVER:OFF /** * Prevent instance from being created. */ private UTF16() { } // /CLOVER:ON // public method ------------------------------------------------------ /** * Extract a single UTF-32 value from a string. Used when iterating forwards or backwards (with *UTF16.getCharCount(), as well as random access. If a validity check is * required, use* UCharacter.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 * * @param source * array of UTF-16 chars * @param offset16 * UTF-16 offset to the start of the character. * @return UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries * of that codepoint are the same as inbounds32(). * @exception IndexOutOfBoundsException * thrown if offset16 is out of bounds. * @stable ICU 2.1 */ public static int charAt(String source, int offset16) { char single = source.charAt(offset16); if (single < LEAD_SURROGATE_MIN_VALUE) { return single; } return _charAt(source, offset16, single); } private static int _charAt(String source, int offset16, char single) { if (single > TRAIL_SURROGATE_MAX_VALUE) { return single; } // Convert the UTF-16 surrogate pair if necessary. // For simplicity in usage, and because the frequency of pairs is // low, look both directions. if (single <= LEAD_SURROGATE_MAX_VALUE) { ++offset16; if (source.length() != offset16) { char trail = source.charAt(offset16); if (trail >= TRAIL_SURROGATE_MIN_VALUE && trail <= TRAIL_SURROGATE_MAX_VALUE) { return UCharacterProperty.getRawSupplementary(single, trail); } } } else { --offset16; if (offset16 >= 0) { // single is a trail surrogate so char lead = source.charAt(offset16); if (lead >= LEAD_SURROGATE_MIN_VALUE && lead <= LEAD_SURROGATE_MAX_VALUE) { return UCharacterProperty.getRawSupplementary(lead, single); } } } return single; // return unmatched surrogate } //#if defined(FOUNDATION10) || defined(J2SE13) //#else /** * Extract a single UTF-32 value from a string. Used when iterating forwards or backwards (with *UTF16.getCharCount(), as well as random access. If a validity check is * required, use* UCharacter.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 * * @param source * array of UTF-16 chars * @param offset16 * UTF-16 offset to the start of the character. * @return UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries * of that codepoint are the same as inbounds32(). * @exception IndexOutOfBoundsException * thrown if offset16 is out of bounds. * @stable ICU 2.1 */ public static int charAt(CharSequence source, int offset16) { char single = source.charAt(offset16); if (single < UTF16.LEAD_SURROGATE_MIN_VALUE) { return single; } return _charAt(source, offset16, single); } private static int _charAt(CharSequence source, int offset16, char single) { if (single > UTF16.TRAIL_SURROGATE_MAX_VALUE) { return single; } // Convert the UTF-16 surrogate pair if necessary. // For simplicity in usage, and because the frequency of pairs is // low, look both directions. if (single <= UTF16.LEAD_SURROGATE_MAX_VALUE) { ++offset16; if (source.length() != offset16) { char trail = source.charAt(offset16); if (trail >= UTF16.TRAIL_SURROGATE_MIN_VALUE && trail <= UTF16.TRAIL_SURROGATE_MAX_VALUE) { return UCharacterProperty.getRawSupplementary(single, trail); } } } else { --offset16; if (offset16 >= 0) { // single is a trail surrogate so char lead = source.charAt(offset16); if (lead >= UTF16.LEAD_SURROGATE_MIN_VALUE && lead <= UTF16.LEAD_SURROGATE_MAX_VALUE) { return UCharacterProperty.getRawSupplementary(lead, single); } } } return single; // return unmatched surrogate } //#endif /** * Extract a single UTF-32 value from a string. Used when iterating forwards or backwards (with *UTF16.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 * * @param source * UTF-16 chars string buffer * @param offset16 * UTF-16 offset to the start of the character. * @return UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries * of that codepoint are the same as inbounds32(). * @exception IndexOutOfBoundsException * thrown if offset16 is out of bounds. * @stable ICU 2.1 */ public static int charAt(StringBuffer source, int offset16) { if (offset16 < 0 || offset16 >= source.length()) { throw new StringIndexOutOfBoundsException(offset16); } char single = source.charAt(offset16); if (!isSurrogate(single)) { return single; } // Convert the UTF-16 surrogate pair if necessary. // For simplicity in usage, and because the frequency of pairs is // low, look both directions. if (single <= LEAD_SURROGATE_MAX_VALUE) { ++offset16; if (source.length() != offset16) { char trail = source.charAt(offset16); if (isTrailSurrogate(trail)) return UCharacterProperty.getRawSupplementary(single, trail); } } else { --offset16; if (offset16 >= 0) { // single is a trail surrogate so char lead = source.charAt(offset16); if (isLeadSurrogate(lead)) { return UCharacterProperty.getRawSupplementary(lead, single); } } } return single; // return unmatched surrogate } /** * 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 * * @param source * array of UTF-16 chars * @param start * offset to substring in the source array for analyzing * @param limit * offset to substring in the source array for analyzing * @param offset16 * UTF-16 offset relative to start * @return UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries * of that codepoint are the same as inbounds32(). * @exception IndexOutOfBoundsException * thrown if offset16 is not within the range of start and limit. * @stable ICU 2.1 */ public static int charAt(char source[], int start, int limit, int offset16) { offset16 += start; if (offset16 < start || offset16 >= limit) { throw new ArrayIndexOutOfBoundsException(offset16); } char single = source[offset16]; if (!isSurrogate(single)) { return single; } // Convert the UTF-16 surrogate pair if necessary. // For simplicity in usage, and because the frequency of pairs is // low, look both directions. if (single <= LEAD_SURROGATE_MAX_VALUE) { offset16++; if (offset16 >= limit) { return single; } char trail = source[offset16]; if (isTrailSurrogate(trail)) { return UCharacterProperty.getRawSupplementary(single, trail); } } else { // isTrailSurrogate(single), so if (offset16 == start) { return single; } offset16--; char lead = source[offset16]; if (isLeadSurrogate(lead)) return UCharacterProperty.getRawSupplementary(lead, single); } return single; // return unmatched surrogate } /** * Extract a single UTF-32 value from a string. Used when iterating forwards or backwards (with *UTF16.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 * * @param source * UTF-16 chars string buffer * @param offset16 * UTF-16 offset to the start of the character. * @return UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries * of that codepoint are the same as inbounds32(). * @exception IndexOutOfBoundsException * thrown if offset16 is out of bounds. * @stable ICU 2.1 */ public static int charAt(Replaceable source, int offset16) { if (offset16 < 0 || offset16 >= source.length()) { throw new StringIndexOutOfBoundsException(offset16); } char single = source.charAt(offset16); if (!isSurrogate(single)) { return single; } // Convert the UTF-16 surrogate pair if necessary. // For simplicity in usage, and because the frequency of pairs is // low, look both directions. if (single <= LEAD_SURROGATE_MAX_VALUE) { ++offset16; if (source.length() != offset16) { char trail = source.charAt(offset16); if (isTrailSurrogate(trail)) return UCharacterProperty.getRawSupplementary(single, trail); } } else { --offset16; if (offset16 >= 0) { // single is a trail surrogate so char lead = source.charAt(offset16); if (isLeadSurrogate(lead)) { return UCharacterProperty.getRawSupplementary(lead, single); } } } return single; // return unmatched surrogate } /** * Determines how many chars this char32 requires. If a validity check is required, use* isLegal()* on char32 before calling. * * @param char32 * the input codepoint. * @return 2 if is in supplementary space, otherwise 1. * @stable ICU 2.1 */ public static int getCharCount(int char32) { if (char32 < SUPPLEMENTARY_MIN_VALUE) { return 1; } return 2; } /** * Returns the type of the boundaries around the char at offset16. Used for random access. * * @param source * text to analyse * @param offset16 * UTF-16 offset * @return **
* For bit-twiddlers, the return values for these are chosen so that the boundaries * can be gotten by: [offset16 - (value >> 2), offset16 + (value & 3)]. * @exception IndexOutOfBoundsException * if offset16 is out of bounds. * @stable ICU 2.1 */ public static int bounds(String source, int offset16) { char ch = source.charAt(offset16); if (isSurrogate(ch)) { if (isLeadSurrogate(ch)) { if (++offset16 < source.length() && isTrailSurrogate(source.charAt(offset16))) { return LEAD_SURROGATE_BOUNDARY; } } else { // isTrailSurrogate(ch), so --offset16; if (offset16 >= 0 && isLeadSurrogate(source.charAt(offset16))) { return TRAIL_SURROGATE_BOUNDARY; } } } return SINGLE_CHAR_BOUNDARY; } /** * Returns the type of the boundaries around the char at offset16. Used for random access. * * @param source * string buffer to analyse * @param offset16 * UTF16 offset * @return *- 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] *
*
* For bit-twiddlers, the return values for these are chosen so that the boundaries * can be gotten by: [offset16 - (value >> 2), offset16 + (value & 3)]. * @exception IndexOutOfBoundsException * if offset16 is out of bounds. * @stable ICU 2.1 */ public static int bounds(StringBuffer source, int offset16) { char ch = source.charAt(offset16); if (isSurrogate(ch)) { if (isLeadSurrogate(ch)) { if (++offset16 < source.length() && isTrailSurrogate(source.charAt(offset16))) { return LEAD_SURROGATE_BOUNDARY; } } else { // isTrailSurrogate(ch), so --offset16; if (offset16 >= 0 && isLeadSurrogate(source.charAt(offset16))) { return TRAIL_SURROGATE_BOUNDARY; } } } return SINGLE_CHAR_BOUNDARY; } /** * 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. * * @param source * char array to analyse * @param start * offset to substring in the source array for analyzing * @param limit * offset to substring in the source array for analyzing * @param offset16 * UTF16 offset relative to start * @return *- 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] *
*
* For bit-twiddlers, the boundary values for these are chosen so that the boundaries * can be gotten by: [offset16 - (boundvalue >> 2), offset16 + (boundvalue & 3)]. * @exception IndexOutOfBoundsException * if offset16 is not within the range of start and limit. * @stable ICU 2.1 */ public static int bounds(char source[], int start, int limit, int offset16) { offset16 += start; if (offset16 < start || offset16 >= limit) { throw new ArrayIndexOutOfBoundsException(offset16); } char ch = source[offset16]; if (isSurrogate(ch)) { if (isLeadSurrogate(ch)) { ++offset16; if (offset16 < limit && isTrailSurrogate(source[offset16])) { return LEAD_SURROGATE_BOUNDARY; } } else { // isTrailSurrogate(ch), so --offset16; if (offset16 >= start && isLeadSurrogate(source[offset16])) { return TRAIL_SURROGATE_BOUNDARY; } } } return SINGLE_CHAR_BOUNDARY; } /** * Determines whether the code value is a surrogate. * * @param char16 * the input character. * @return true iff the input character is a surrogate. * @stable ICU 2.1 */ public static boolean isSurrogate(char char16) { return (char16 & SURROGATE_BITMASK) == SURROGATE_BITS; } /** * Determines whether the character is a trail surrogate. * * @param char16 * the input character. * @return true iff the input character is a trail surrogate. * @stable ICU 2.1 */ public static boolean isTrailSurrogate(char char16) { return (char16 & TRAIL_SURROGATE_BITMASK) == TRAIL_SURROGATE_BITS; } /** * Determines whether the character is a lead surrogate. * * @param char16 * the input character. * @return true iff the input character is a lead surrogate * @stable ICU 2.1 */ public static boolean isLeadSurrogate(char char16) { return (char16 & LEAD_SURROGATE_BITMASK) == LEAD_SURROGATE_BITS; } /** * Returns the lead surrogate. If a validity check is required, use *- 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] *
isLegal()on char32 * before calling. * * @param char32 * the input character. * @return lead surrogate if the getCharCount(ch) is 2;
* and 0 otherwise (note: 0 is not a valid lead surrogate). * @stable ICU 2.1 */ public static char getLeadSurrogate(int char32) { if (char32 >= SUPPLEMENTARY_MIN_VALUE) { return (char) (LEAD_SURROGATE_OFFSET_ + (char32 >> LEAD_SURROGATE_SHIFT_)); } return 0; } /** * Returns the trail surrogate. If a validity check is required, use *isLegal()on char32 * before calling. * * @param char32 * the input character. * @return the trail surrogate if the getCharCount(ch) is 2;
* otherwise the character itself * @stable ICU 2.1 */ public static char getTrailSurrogate(int char32) { if (char32 >= SUPPLEMENTARY_MIN_VALUE) { return (char) (TRAIL_SURROGATE_MIN_VALUE + (char32 & TRAIL_SURROGATE_MASK_)); } return (char) 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()
* 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()); ** * ** * @param source * text to analyse * @param offset16 * UTF-16 offset < source text length. * @return UTF-32 offset * @exception IndexOutOfBoundsException * if offset16 is out of bounds. * @stable ICU 2.1 */ public static int findCodePointOffset(String source, int offset16) { if (offset16 < 0 || offset16 > source.length()) { throw new StringIndexOutOfBoundsException(offset16); } int result = 0; char ch; boolean hadLeadSurrogate = false; for (int i = 0; i < offset16; ++i) { ch = source.charAt(i); if (hadLeadSurrogate && isTrailSurrogate(ch)) { hadLeadSurrogate = false; // count valid trail as zero } else { hadLeadSurrogate = isLeadSurrogate(ch); ++result; // count others as 1 } } if (offset16 == source.length()) { return result; } // end of source being the less significant surrogate character // shift result back to the start of the supplementary character if (hadLeadSurrogate && (isTrailSurrogate(source.charAt(offset16)))) { result--; } return result; } /** * 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); ** * ** * @param source * text to analyse * @param offset16 * UTF-16 offset < source text length. * @return UTF-32 offset * @exception IndexOutOfBoundsException * if offset16 is out of bounds. * @stable ICU 2.1 */ public static int findCodePointOffset(StringBuffer source, int offset16) { if (offset16 < 0 || offset16 > source.length()) { throw new StringIndexOutOfBoundsException(offset16); } int result = 0; char ch; boolean hadLeadSurrogate = false; for (int i = 0; i < offset16; ++i) { ch = source.charAt(i); if (hadLeadSurrogate && isTrailSurrogate(ch)) { hadLeadSurrogate = false; // count valid trail as zero } else { hadLeadSurrogate = isLeadSurrogate(ch); ++result; // count others as 1 } } if (offset16 == source.length()) { return result; } // end of source being the less significant surrogate character // shift result back to the start of the supplementary character if (hadLeadSurrogate && (isTrailSurrogate(source.charAt(offset16)))) { result--; } return result; } /** * 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); ** * ** * @param source * text to analyse * @param start * offset of the substring * @param limit * offset of the substring * @param offset16 * UTF-16 relative to start * @return UTF-32 offset relative to start * @exception IndexOutOfBoundsException * if offset16 is not within the range of start and limit. * @stable ICU 2.1 */ public static int findCodePointOffset(char source[], int start, int limit, int offset16) { offset16 += start; if (offset16 > limit) { throw new StringIndexOutOfBoundsException(offset16); } int result = 0; char ch; boolean hadLeadSurrogate = false; for (int i = start; i < offset16; ++i) { ch = source[i]; if (hadLeadSurrogate && isTrailSurrogate(ch)) { hadLeadSurrogate = false; // count valid trail as zero } else { hadLeadSurrogate = isLeadSurrogate(ch); ++result; // count others as 1 } } if (offset16 == limit) { return result; } // end of source being the less significant surrogate character // shift result back to the start of the supplementary character if (hadLeadSurrogate && (isTrailSurrogate(source[offset16]))) { result--; } return result; } /** * Append a single UTF-32 value to the end of a StringBuffer. If a validity check is required, * use isLegal() on char32 before * calling. * * @param target * the buffer to append to * @param char32 * value to append. * @return the updated StringBuffer * @exception IllegalArgumentException * thrown when char32 does not lie within the range of the Unicode codepoints * @stable ICU 2.1 */ public static StringBuffer append(StringBuffer target, int char32) { // Check for irregular values if (char32 < CODEPOINT_MIN_VALUE || char32 > CODEPOINT_MAX_VALUE) { throw new IllegalArgumentException("Illegal codepoint: " + Integer.toHexString(char32)); } // Write the UTF-16 values if (char32 >= SUPPLEMENTARY_MIN_VALUE) { target.append(getLeadSurrogate(char32)); target.append(getTrailSurrogate(char32)); } else { target.append((char) char32); } return target; } /** * Cover JDK 1.5 APIs. Append the code point to the buffer and return the buffer as a * convenience. * * @param target * the buffer to append to * @param cp * the code point to append * @return the updated StringBuffer * @throws IllegalArgumentException * if cp is not a valid code point * @stable ICU 3.0 */ public static StringBuffer appendCodePoint(StringBuffer target, int cp) { return append(target, cp); } /** * Adds a codepoint to offset16 position of the argument char array. * * @param target * char array to be append with the new code point * @param limit * UTF16 offset which the codepoint will be appended. * @param char32 * code point to be appended * @return offset after char32 in the array. * @exception IllegalArgumentException * thrown if there is not enough space for the append, or when char32 does not * lie within the range of the Unicode codepoints. * @stable ICU 2.1 */ public static int append(char[] target, int limit, int char32) { // Check for irregular values if (char32 < CODEPOINT_MIN_VALUE || char32 > CODEPOINT_MAX_VALUE) { throw new IllegalArgumentException("Illegal codepoint"); } // Write the UTF-16 values if (char32 >= SUPPLEMENTARY_MIN_VALUE) { target[limit++] = getLeadSurrogate(char32); target[limit++] = getTrailSurrogate(char32); } else { target[limit++] = (char) char32; } return limit; } /** * Number of codepoints in a UTF16 String * * @param source * UTF16 string * @return number of codepoint in string * @stable ICU 2.1 */ public static int countCodePoint(String source) { if (source == null || source.length() == 0) { return 0; } return findCodePointOffset(source, source.length()); } /** * Number of codepoints in a UTF16 String buffer * * @param source * UTF16 string buffer * @return number of codepoint in string * @stable ICU 2.1 */ public static int countCodePoint(StringBuffer source) { if (source == null || source.length() == 0) { return 0; } return findCodePointOffset(source, source.length()); } /** * Number of codepoints in a UTF16 char array substring * * @param source * UTF16 char array * @param start * offset of the substring * @param limit * offset of the substring * @return number of codepoint in the substring * @exception IndexOutOfBoundsException * if start and limit are not valid. * @stable ICU 2.1 */ public static int countCodePoint(char source[], int start, int limit) { if (source == null || source.length == 0) { return 0; } return findCodePointOffset(source, start, limit, limit - start); } /** * 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. * * @param target * stringbuffer * @param offset16 * UTF16 position to insert into * @param char32 * code point * @stable ICU 2.1 */ public static void setCharAt(StringBuffer target, int offset16, int char32) { int count = 1; char single = target.charAt(offset16); if (isSurrogate(single)) { // pairs of the surrogate with offset16 at the lead char found if (isLeadSurrogate(single) && (target.length() > offset16 + 1) && isTrailSurrogate(target.charAt(offset16 + 1))) { count++; } else { // pairs of the surrogate with offset16 at the trail char // found if (isTrailSurrogate(single) && (offset16 > 0) && isLeadSurrogate(target.charAt(offset16 - 1))) { offset16--; count++; } } } target.replace(offset16, offset16 + count, valueOf(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. * * @param target * char array * @param 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. * @param offset16 * UTF16 position to insert into * @param char32 * code point * @return new number of chars in target that represents a string * @exception IndexOutOfBoundsException * if offset16 is out of range * @stable ICU 2.1 */ public static int setCharAt(char target[], int limit, int offset16, int char32) { if (offset16 >= limit) { throw new ArrayIndexOutOfBoundsException(offset16); } int count = 1; char single = target[offset16]; if (isSurrogate(single)) { // pairs of the surrogate with offset16 at the lead char found if (isLeadSurrogate(single) && (target.length > offset16 + 1) && isTrailSurrogate(target[offset16 + 1])) { count++; } else { // pairs of the surrogate with offset16 at the trail char // found if (isTrailSurrogate(single) && (offset16 > 0) && isLeadSurrogate(target[offset16 - 1])) { offset16--; count++; } } } String str = valueOf(char32); int result = limit; int strlength = str.length(); target[offset16] = str.charAt(0); if (count == strlength) { if (count == 2) { target[offset16 + 1] = str.charAt(1); } } else { // this is not exact match in space, we'll have to do some // shifting System.arraycopy(target, offset16 + count, target, offset16 + strlength, limit - (offset16 + count)); if (count < strlength) { // char32 is a supplementary character trying to squeeze into // a non-supplementary space target[offset16 + 1] = str.charAt(1); result++; if (result < target.length) { target[result] = 0; } } else { // char32 is a non-supplementary character trying to fill // into a supplementary space result--; target[result] = 0; } } return result; } /** * Shifts offset16 by the argument number of codepoints * * @param source * string * @param offset16 * UTF16 position to shift * @param shift32 * number of codepoints to shift * @return new shifted offset16 * @exception IndexOutOfBoundsException * if the new offset16 is out of bounds. * @stable ICU 2.1 */ public static int moveCodePointOffset(String source, int offset16, int shift32) { int result = offset16; int size = source.length(); int count; char ch; if (offset16 < 0 || offset16 > size) { throw new StringIndexOutOfBoundsException(offset16); } if (shift32 > 0) { if (shift32 + offset16 > size) { throw new StringIndexOutOfBoundsException(offset16); } count = shift32; while (result < size && count > 0) { ch = source.charAt(result); if (isLeadSurrogate(ch) && ((result + 1) < size) && isTrailSurrogate(source.charAt(result + 1))) { result++; } count--; result++; } } else { if (offset16 + shift32 < 0) { throw new StringIndexOutOfBoundsException(offset16); } for (count = -shift32; count > 0; count--) { result--; if (result < 0) { break; } ch = source.charAt(result); if (isTrailSurrogate(ch) && result > 0 && isLeadSurrogate(source.charAt(result - 1))) { result--; } } } if (count != 0) { throw new StringIndexOutOfBoundsException(shift32); } return result; } /** * Shifts offset16 by the argument number of codepoints * * @param source * string buffer * @param offset16 * UTF16 position to shift * @param shift32 * number of codepoints to shift * @return new shifted offset16 * @exception IndexOutOfBoundsException * if the new offset16 is out of bounds. * @stable ICU 2.1 */ public static int moveCodePointOffset(StringBuffer source, int offset16, int shift32) { int result = offset16; int size = source.length(); int count; char ch; if (offset16 < 0 || offset16 > size) { throw new StringIndexOutOfBoundsException(offset16); } if (shift32 > 0) { if (shift32 + offset16 > size) { throw new StringIndexOutOfBoundsException(offset16); } count = shift32; while (result < size && count > 0) { ch = source.charAt(result); if (isLeadSurrogate(ch) && ((result + 1) < size) && isTrailSurrogate(source.charAt(result + 1))) { result++; } count--; result++; } } else { if (offset16 + shift32 < 0) { throw new StringIndexOutOfBoundsException(offset16); } for (count = -shift32; count > 0; count--) { result--; if (result < 0) { break; } ch = source.charAt(result); if (isTrailSurrogate(ch) && result > 0 && isLeadSurrogate(source.charAt(result - 1))) { result--; } } } if (count != 0) { throw new StringIndexOutOfBoundsException(shift32); } return result; } /** * Shifts offset16 by the argument number of codepoints within a subarray. * * @param source * char array * @param start * position of the subarray to be performed on * @param limit * position of the subarray to be performed on * @param offset16 * UTF16 position to shift relative to start * @param shift32 * number of codepoints to shift * @return new shifted offset16 relative to start * @exception IndexOutOfBoundsException * if the new offset16 is out of bounds with respect to the subarray or the * subarray bounds are out of range. * @stable ICU 2.1 */ public static int moveCodePointOffset(char source[], int start, int limit, int offset16, int shift32) { int size = source.length; int count; char ch; int result = offset16 + start; if (start < 0 || limit < start) { throw new StringIndexOutOfBoundsException(start); } if (limit > size) { throw new StringIndexOutOfBoundsException(limit); } if (offset16 < 0 || result > limit) { throw new StringIndexOutOfBoundsException(offset16); } if (shift32 > 0) { if (shift32 + result > size) { throw new StringIndexOutOfBoundsException(result); } count = shift32; while (result < limit && count > 0) { ch = source[result]; if (isLeadSurrogate(ch) && (result + 1 < limit) && isTrailSurrogate(source[result + 1])) { result++; } count--; result++; } } else { if (result + shift32 < start) { throw new StringIndexOutOfBoundsException(result); } for (count = -shift32; count > 0; count--) { result--; if (result < start) { break; } ch = source[result]; if (isTrailSurrogate(ch) && result > start && isLeadSurrogate(source[result - 1])) { result--; } } } if (count != 0) { throw new StringIndexOutOfBoundsException(shift32); } result -= start; return result; } /** * 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. * * @param target * string buffer to insert to * @param offset16 * offset which char32 will be inserted in * @param char32 * codepoint to be inserted * @return a reference to target * @exception IndexOutOfBoundsException * thrown if offset16 is invalid. * @stable ICU 2.1 */ public static StringBuffer insert(StringBuffer target, int offset16, int char32) { String str = valueOf(char32); if (offset16 != target.length() && bounds(target, offset16) == TRAIL_SURROGATE_BOUNDARY) { offset16++; } target.insert(offset16, str); return target; } /** * 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. * * @param target * char array to insert to * @param limit * end index of the char array, limit <= target.length * @param offset16 * offset which char32 will be inserted in * @param char32 * codepoint to be inserted * @return new limit size * @exception IndexOutOfBoundsException * thrown if offset16 is invalid. * @stable ICU 2.1 */ public static int insert(char target[], int limit, int offset16, int char32) { String str = valueOf(char32); if (offset16 != limit && bounds(target, 0, limit, offset16) == TRAIL_SURROGATE_BOUNDARY) { offset16++; } int size = str.length(); if (limit + size > target.length) { throw new ArrayIndexOutOfBoundsException(offset16 + size); } System.arraycopy(target, offset16, target, offset16 + size, limit - offset16); target[offset16] = str.charAt(0); if (size == 2) { target[offset16 + 1] = str.charAt(1); } return limit + size; } /** * Removes the codepoint at the specified position in this target (shortening target by 1 * character if the codepoint is a non-supplementary, 2 otherwise). * * @param target * string buffer to remove codepoint from * @param offset16 * offset which the codepoint will be removed * @return a reference to target * @exception IndexOutOfBoundsException * thrown if offset16 is invalid. * @stable ICU 2.1 */ public static StringBuffer delete(StringBuffer target, int offset16) { int count = 1; switch (bounds(target, offset16)) { case LEAD_SURROGATE_BOUNDARY: count++; break; case TRAIL_SURROGATE_BOUNDARY: count++; offset16--; break; } target.delete(offset16, offset16 + count); return target; } /** * Removes the codepoint at the specified position in this target (shortening target by 1 * character if the codepoint is a non-supplementary, 2 otherwise). * * @param target * string buffer to remove codepoint from * @param limit * end index of the char array, limit <= target.length * @param offset16 * offset which the codepoint will be removed * @return a new limit size * @exception IndexOutOfBoundsException * thrown if offset16 is invalid. * @stable ICU 2.1 */ public static int delete(char target[], int limit, int offset16) { int count = 1; switch (bounds(target, 0, limit, offset16)) { case LEAD_SURROGATE_BOUNDARY: count++; break; case TRAIL_SURROGATE_BOUNDARY: count++; offset16--; break; } System.arraycopy(target, offset16 + count, target, offset16, limit - (offset16 + count)); target[limit - count] = 0; return limit - count; } /** * Returns the index within the argument UTF16 format Unicode string of the first occurrence of * the argument codepoint. I.e., the smallest index
isuch that *UTF16.charAt(source, i) == * char32is true. ** If no such character occurs in this string, then -1 is returned. *
** Examples:
* Note this method is provided as support to jdk 1.3, which does not support supplementary * characters to its fullest. * * @param source * UTF16 format Unicode string that will be searched * @param char32 * codepoint to search for * @return the index of the first occurrence of the codepoint in the argument Unicode string, or * -1 if the codepoint does not occur. * @stable ICU 2.6 */ public static int indexOf(String source, int char32) { if (char32 < CODEPOINT_MIN_VALUE || char32 > CODEPOINT_MAX_VALUE) { throw new IllegalArgumentException("Argument char32 is not a valid codepoint"); } // non-surrogate bmp if (char32 < LEAD_SURROGATE_MIN_VALUE || (char32 > TRAIL_SURROGATE_MAX_VALUE && char32 < SUPPLEMENTARY_MIN_VALUE)) { return source.indexOf((char) char32); } // surrogate if (char32 < SUPPLEMENTARY_MIN_VALUE) { int result = source.indexOf((char) char32); if (result >= 0) { if (isLeadSurrogate((char) char32) && (result < source.length() - 1) && isTrailSurrogate(source.charAt(result + 1))) { return indexOf(source, char32, result + 1); } // trail surrogate if (result > 0 && isLeadSurrogate(source.charAt(result - 1))) { return indexOf(source, char32, result + 1); } } return result; } // supplementary String char32str = toString(char32); return source.indexOf(char32str); } /** * 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. *
* UTF16.indexOf("abc", 'a') returns 0
* UTF16.indexOf("abc\ud800\udc00", 0x10000) returns 3
* UTF16.indexOf("abc\ud800\udc00", 0xd800) returns -1
** If no such string str occurs in this source, then -1 is returned. *
** Examples:
* Note this method is provided as support to jdk 1.3, which does not support supplementary * characters to its fullest. * * @param source * UTF16 format Unicode string that will be searched * @param str * UTF16 format Unicode string to search for * @return the index of the first occurrence of the codepoint in the argument Unicode string, or * -1 if the codepoint does not occur. * @stable ICU 2.6 */ public static int indexOf(String source, String str) { int strLength = str.length(); // non-surrogate ends if (!isTrailSurrogate(str.charAt(0)) && !isLeadSurrogate(str.charAt(strLength - 1))) { return source.indexOf(str); } int result = source.indexOf(str); int resultEnd = result + strLength; if (result >= 0) { // check last character if (isLeadSurrogate(str.charAt(strLength - 1)) && (result < source.length() - 1) && isTrailSurrogate(source.charAt(resultEnd + 1))) { return indexOf(source, str, resultEnd + 1); } // check first character which is a trail surrogate if (isTrailSurrogate(str.charAt(0)) && result > 0 && isLeadSurrogate(source.charAt(result - 1))) { return indexOf(source, str, resultEnd + 1); } } return result; } /** * 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.indexOf("abc", "ab") returns 0
* UTF16.indexOf("abc\ud800\udc00", "\ud800\udc00") returns 3
* UTF16.indexOf("abc\ud800\udc00", "\ud800") returns -1
*
* (UTF16.charAt(source, i) == char32 && i >= fromIndex) is true. ** If no such character occurs in this string, then -1 is returned. *
** Examples:
* Note this method is provided as support to jdk 1.3, which does not support supplementary * characters to its fullest. * * @param source * UTF16 format Unicode string that will be searched * @param char32 * codepoint to search for * @param fromIndex * the index to start the search from. * @return 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. * @stable ICU 2.6 */ public static int indexOf(String source, int char32, int fromIndex) { if (char32 < CODEPOINT_MIN_VALUE || char32 > CODEPOINT_MAX_VALUE) { throw new IllegalArgumentException("Argument char32 is not a valid codepoint"); } // non-surrogate bmp if (char32 < LEAD_SURROGATE_MIN_VALUE || (char32 > TRAIL_SURROGATE_MAX_VALUE && char32 < SUPPLEMENTARY_MIN_VALUE)) { return source.indexOf((char) char32, fromIndex); } // surrogate if (char32 < SUPPLEMENTARY_MIN_VALUE) { int result = source.indexOf((char) char32, fromIndex); if (result >= 0) { if (isLeadSurrogate((char) char32) && (result < source.length() - 1) && isTrailSurrogate(source.charAt(result + 1))) { return indexOf(source, char32, result + 1); } // trail surrogate if (result > 0 && isLeadSurrogate(source.charAt(result - 1))) { return indexOf(source, char32, result + 1); } } return result; } // supplementary String char32str = toString(char32); return source.indexOf(char32str, 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. *
* 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
** If no such string str occurs in this source, then -1 is returned. *
** Examples:
* Note this method is provided as support to jdk 1.3, which does not support supplementary * characters to its fullest. * * @param source * UTF16 format Unicode string that will be searched * @param str * UTF16 format Unicode string to search for * @param fromIndex * the index to start the search from. * @return the index of the first occurrence of the codepoint in the argument Unicode string, or * -1 if the codepoint does not occur. * @stable ICU 2.6 */ public static int indexOf(String source, String str, int fromIndex) { int strLength = str.length(); // non-surrogate ends if (!isTrailSurrogate(str.charAt(0)) && !isLeadSurrogate(str.charAt(strLength - 1))) { return source.indexOf(str, fromIndex); } int result = source.indexOf(str, fromIndex); int resultEnd = result + strLength; if (result >= 0) { // check last character if (isLeadSurrogate(str.charAt(strLength - 1)) && (result < source.length() - 1) && isTrailSurrogate(source.charAt(resultEnd))) { return indexOf(source, str, resultEnd + 1); } // check first character which is a trail surrogate if (isTrailSurrogate(str.charAt(0)) && result > 0 && isLeadSurrogate(source.charAt(result - 1))) { return indexOf(source, str, resultEnd + 1); } } return result; } /** * 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. *
* 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
** 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. * * @param source * UTF16 format Unicode string that will be searched * @param char32 * codepoint to search for * @return the index of the last occurrence of the codepoint in source, or -1 if the codepoint * does not occur. * @stable ICU 2.6 */ public static int lastIndexOf(String source, int char32) { if (char32 < CODEPOINT_MIN_VALUE || char32 > CODEPOINT_MAX_VALUE) { throw new IllegalArgumentException("Argument char32 is not a valid codepoint"); } // non-surrogate bmp if (char32 < LEAD_SURROGATE_MIN_VALUE || (char32 > TRAIL_SURROGATE_MAX_VALUE && char32 < SUPPLEMENTARY_MIN_VALUE)) { return source.lastIndexOf((char) char32); } // surrogate if (char32 < SUPPLEMENTARY_MIN_VALUE) { int result = source.lastIndexOf((char) char32); if (result >= 0) { if (isLeadSurrogate((char) char32) && (result < source.length() - 1) && isTrailSurrogate(source.charAt(result + 1))) { return lastIndexOf(source, char32, result - 1); } // trail surrogate if (result > 0 && isLeadSurrogate(source.charAt(result - 1))) { return lastIndexOf(source, char32, result - 1); } } return result; } // supplementary String char32str = toString(char32); return source.lastIndexOf(char32str); } /** * 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. * * @param source * UTF16 format Unicode string that will be searched * @param str * UTF16 format Unicode string to search for * @return the index of the last occurrence of the codepoint in source, or -1 if the codepoint * does not occur. * @stable ICU 2.6 */ public static int lastIndexOf(String source, String str) { int strLength = str.length(); // non-surrogate ends if (!isTrailSurrogate(str.charAt(0)) && !isLeadSurrogate(str.charAt(strLength - 1))) { return source.lastIndexOf(str); } int result = source.lastIndexOf(str); if (result >= 0) { // check last character if (isLeadSurrogate(str.charAt(strLength - 1)) && (result < source.length() - 1) && isTrailSurrogate(source.charAt(result + strLength + 1))) { return lastIndexOf(source, str, result - 1); } // check first character which is a trail surrogate if (isTrailSurrogate(str.charAt(0)) && result > 0 && isLeadSurrogate(source.charAt(result - 1))) { return lastIndexOf(source, str, result - 1); } } return result; } /** ** 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:
* Note this method is provided as support to jdk 1.3, which does not support supplementary * characters to its fullest. * * @param source * UTF16 format Unicode string that will be searched * @param char32 * codepoint to search for * @param fromIndex * 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. * @return the index of the last occurrence of the codepoint in source, or -1 if the codepoint * does not occur. * @stable ICU 2.6 */ public static int lastIndexOf(String source, int char32, int fromIndex) { if (char32 < CODEPOINT_MIN_VALUE || char32 > CODEPOINT_MAX_VALUE) { throw new IllegalArgumentException("Argument char32 is not a valid codepoint"); } // non-surrogate bmp if (char32 < LEAD_SURROGATE_MIN_VALUE || (char32 > TRAIL_SURROGATE_MAX_VALUE && char32 < SUPPLEMENTARY_MIN_VALUE)) { return source.lastIndexOf((char) char32, fromIndex); } // surrogate if (char32 < SUPPLEMENTARY_MIN_VALUE) { int result = source.lastIndexOf((char) char32, fromIndex); if (result >= 0) { if (isLeadSurrogate((char) char32) && (result < source.length() - 1) && isTrailSurrogate(source.charAt(result + 1))) { return lastIndexOf(source, char32, result - 1); } // trail surrogate if (result > 0 && isLeadSurrogate(source.charAt(result - 1))) { return lastIndexOf(source, char32, result - 1); } } return result; } // supplementary String char32str = toString(char32); return source.lastIndexOf(char32str, fromIndex); } /** *
* 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
** 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. * * @param source * UTF16 format Unicode string that will be searched * @param str * UTF16 format Unicode string to search for * @param fromIndex * 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. * @return the index of the last occurrence of the codepoint in source, or -1 if the codepoint * does not occur. * @stable ICU 2.6 */ public static int lastIndexOf(String source, String str, int fromIndex) { int strLength = str.length(); // non-surrogate ends if (!isTrailSurrogate(str.charAt(0)) && !isLeadSurrogate(str.charAt(strLength - 1))) { return source.lastIndexOf(str, fromIndex); } int result = source.lastIndexOf(str, fromIndex); if (result >= 0) { // check last character if (isLeadSurrogate(str.charAt(strLength - 1)) && (result < source.length() - 1) && isTrailSurrogate(source.charAt(result + strLength))) { return lastIndexOf(source, str, result - 1); } // check first character which is a trail surrogate if (isTrailSurrogate(str.charAt(0)) && result > 0 && isLeadSurrogate(source.charAt(result - 1))) { return lastIndexOf(source, str, result - 1); } } return result; } /** * 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:
* Note this method is provided as support to jdk 1.3, which does not support supplementary * characters to its fullest. * * @param source * UTF16 format Unicode string which the codepoint replacements will be based on. * @param oldChar32 * non-zero old codepoint to be replaced. * @param newChar32 * the new codepoint to replace oldChar32 * @return 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. * @stable ICU 2.6 */ public static String replace(String source, int oldChar32, int newChar32) { if (oldChar32 <= 0 || oldChar32 > CODEPOINT_MAX_VALUE) { throw new IllegalArgumentException("Argument oldChar32 is not a valid codepoint"); } if (newChar32 <= 0 || newChar32 > CODEPOINT_MAX_VALUE) { throw new IllegalArgumentException("Argument newChar32 is not a valid codepoint"); } int index = indexOf(source, oldChar32); if (index == -1) { return source; } String newChar32Str = toString(newChar32); int oldChar32Size = 1; int newChar32Size = newChar32Str.length(); StringBuffer result = new StringBuffer(source); int resultIndex = index; if (oldChar32 >= SUPPLEMENTARY_MIN_VALUE) { oldChar32Size = 2; } while (index != -1) { int endResultIndex = resultIndex + oldChar32Size; result.replace(resultIndex, endResultIndex, newChar32Str); int lastEndIndex = index + oldChar32Size; index = indexOf(source, oldChar32, lastEndIndex); resultIndex += newChar32Size + index - lastEndIndex; } return result.toString(); } /** * 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. *
* 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"
** Examples:
* Note this method is provided as support to jdk 1.3, which does not support supplementary * characters to its fullest. * * @param source * UTF16 format Unicode string which the replacements will be based on. * @param oldStr * non-zero-length string to be replaced. * @param newStr * the new string to replace oldStr * @return 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. * @stable ICU 2.6 */ public static String replace(String source, String oldStr, String newStr) { int index = indexOf(source, oldStr); if (index == -1) { return source; } int oldStrSize = oldStr.length(); int newStrSize = newStr.length(); StringBuffer result = new StringBuffer(source); int resultIndex = index; while (index != -1) { int endResultIndex = resultIndex + oldStrSize; result.replace(resultIndex, endResultIndex, newStr); int lastEndIndex = index + oldStrSize; index = indexOf(source, oldStr, lastEndIndex); resultIndex += newStrSize + index - lastEndIndex; } return result.toString(); } /** * 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. *
* 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"
** Examples:
* UTF16.reverse(new StringBuffer( "Supplementary characters \ud800\udc00\ud801\udc01"))
* returns "\ud801\udc01\ud800\udc00 sretcarahc yratnemelppuS". * * @param source * the source StringBuffer that contains UTF16 format Unicode string to be reversed * @return a modified source with reversed UTF16 format Unicode string. * @stable ICU 2.6 */ public static StringBuffer reverse(StringBuffer source) { int length = source.length(); StringBuffer result = new StringBuffer(length); for (int i = length; i-- > 0;) { char ch = source.charAt(i); if (isTrailSurrogate(ch) && i > 0) { char ch2 = source.charAt(i - 1); if (isLeadSurrogate(ch2)) { result.append(ch2); result.append(ch); --i; continue; } } result.append(ch); } return result; } /** * 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. * * @param source * The input string. * @param number * The number of code points in the string is compared against the 'number' * parameter. * @return boolean value for whether the string contains more Unicode code points than 'number'. * @stable ICU 2.4 */ public static boolean hasMoreCodePointsThan(String source, int number) { if (number < 0) { return true; } if (source == null) { return false; } int length = source.length(); // length >= 0 known // source contains at least (length + 1) / 2 code points: <= 2 // chars per cp if (((length + 1) >> 1) > number) { return true; } // check if source does not even contain enough chars int maxsupplementary = length - number; if (maxsupplementary <= 0) { return false; } // there are maxsupplementary = length - number more chars than // asked-for code points // count code points until they exceed and also check that there are // no more than maxsupplementary supplementary code points (char pairs) int start = 0; while (true) { if (length == 0) { return false; } if (number == 0) { return true; } if (isLeadSurrogate(source.charAt(start++)) && start != length && isTrailSurrogate(source.charAt(start))) { start++; if (--maxsupplementary <= 0) { // too many pairs - too few code points return false; } } --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. * * @param source * array of UTF-16 chars * @param start * offset to substring in the source array for analyzing * @param limit * offset to substring in the source array for analyzing * @param number * The number of code points in the string is compared against the 'number' * parameter. * @return boolean value for whether the string contains more Unicode code points than 'number'. * @exception IndexOutOfBoundsException * thrown when limit < start * @stable ICU 2.4 */ public static boolean hasMoreCodePointsThan(char source[], int start, int limit, int number) { int length = limit - start; if (length < 0 || start < 0 || limit < 0) { throw new IndexOutOfBoundsException( "Start and limit indexes should be non-negative and start <= limit"); } if (number < 0) { return true; } if (source == null) { return false; } // length >= 0 known // source contains at least (length + 1) / 2 code points: <= 2 // chars per cp if (((length + 1) >> 1) > number) { return true; } // check if source does not even contain enough chars int maxsupplementary = length - number; if (maxsupplementary <= 0) { return false; } // there are maxsupplementary = length - number more chars than // asked-for code points // count code points until they exceed and also check that there are // no more than maxsupplementary supplementary code points (char pairs) while (true) { if (length == 0) { return false; } if (number == 0) { return true; } if (isLeadSurrogate(source[start++]) && start != limit && isTrailSurrogate(source[start])) { start++; if (--maxsupplementary <= 0) { // too many pairs - too few code points return false; } } --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. * * @param source * The input string buffer. * @param number * The number of code points in the string buffer is compared against the 'number' * parameter. * @return boolean value for whether the string buffer contains more Unicode code points than * 'number'. * @stable ICU 2.4 */ public static boolean hasMoreCodePointsThan(StringBuffer source, int number) { if (number < 0) { return true; } if (source == null) { return false; } int length = source.length(); // length >= 0 known // source contains at least (length + 1) / 2 code points: <= 2 // chars per cp if (((length + 1) >> 1) > number) { return true; } // check if source does not even contain enough chars int maxsupplementary = length - number; if (maxsupplementary <= 0) { return false; } // there are maxsupplementary = length - number more chars than // asked-for code points // count code points until they exceed and also check that there are // no more than maxsupplementary supplementary code points (char pairs) int start = 0; while (true) { if (length == 0) { return false; } if (number == 0) { return true; } if (isLeadSurrogate(source.charAt(start++)) && start != length && isTrailSurrogate(source.charAt(start))) { start++; if (--maxsupplementary <= 0) { // too many pairs - too few code points return false; } } --number; } } /** * Cover JDK 1.5 API. Create a String from an array of codePoints. * * @param codePoints * the code array * @param offset * the start of the text in the code point array * @param count * the number of code points * @return a String representing the code points between offset and count * @throws IllegalArgumentException * if an invalid code point is encountered * @throws IndexOutOfBoundsException * if the offset or count are out of bounds. * @stable ICU 3.0 */ public static String newString(int[] codePoints, int offset, int count) { if (count < 0) { throw new IllegalArgumentException(); } char[] chars = new char[count]; int w = 0; for (int r = offset, e = offset + count; r < e; ++r) { int cp = codePoints[r]; if (cp < 0 || cp > 0x10ffff) { throw new IllegalArgumentException(); } while (true) { try { if (cp < 0x010000) { chars[w] = (char) cp; w++; } else { chars[w] = (char) (LEAD_SURROGATE_OFFSET_ + (cp >> LEAD_SURROGATE_SHIFT_)); chars[w + 1] = (char) (TRAIL_SURROGATE_MIN_VALUE + (cp & TRAIL_SURROGATE_MASK_)); w += 2; } break; } catch (IndexOutOfBoundsException ex) { int newlen = (int) (Math.ceil((double) codePoints.length * (w + 2) / (r - offset + 1))); char[] temp = new char[newlen]; System.arraycopy(chars, 0, temp, 0, w); chars = temp; } } } return new String(chars, 0, w); } // private data members ------------------------------------------------- /** * Shift value for lead surrogate to form a supplementary character. */ private static final int LEAD_SURROGATE_SHIFT_ = 10; /** * Mask to retrieve the significant value from a trail surrogate. */ private static final int TRAIL_SURROGATE_MASK_ = 0x3FF; /** * Value that all lead surrogate starts with */ private static final int LEAD_SURROGATE_OFFSET_ = LEAD_SURROGATE_MIN_VALUE - (SUPPLEMENTARY_MIN_VALUE >> LEAD_SURROGATE_SHIFT_); // private methods ------------------------------------------------------ /** ** Converts argument code point and returns a String object representing the code point's value * in UTF16 format. *
** This method does not check for the validity of the codepoint, the results are not guaranteed * if a invalid codepoint is passed as argument. *
** The result is a string whose length is 1 for non-supplementary code points, 2 otherwise. *
* * @param ch * code point * @return string representation of the code point */ private static String toString(int ch) { if (ch < SUPPLEMENTARY_MIN_VALUE) { return String.valueOf((char) ch); } StringBuffer result = new StringBuffer(); result.append(getLeadSurrogate(ch)); result.append(getTrailSurrogate(ch)); return result.toString(); } } // eof