1 /*
2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
74 return count;
75 }
76
77 /**
78 * Returns the current capacity. The capacity is the amount of storage
79 * available for newly inserted characters, beyond which an allocation
80 * will occur.
81 *
82 * @return the current capacity
83 */
84 public int capacity() {
85 return value.length;
86 }
87
88 /**
89 * Ensures that the capacity is at least equal to the specified minimum.
90 * If the current capacity is less than the argument, then a new internal
91 * array is allocated with greater capacity. The new capacity is the
92 * larger of:
93 * <ul>
94 * <li>The <code>minimumCapacity</code> argument.
95 * <li>Twice the old capacity, plus <code>2</code>.
96 * </ul>
97 * If the <code>minimumCapacity</code> argument is nonpositive, this
98 * method takes no action and simply returns.
99 *
100 * @param minimumCapacity the minimum desired capacity.
101 */
102 public void ensureCapacity(int minimumCapacity) {
103 if (minimumCapacity > 0)
104 ensureCapacityInternal(minimumCapacity);
105 }
106
107 /**
108 * This method has the same contract as ensureCapacity, but is
109 * never synchronized.
110 */
111 private void ensureCapacityInternal(int minimumCapacity) {
112 // overflow-conscious code
113 if (minimumCapacity - value.length > 0)
114 expandCapacity(minimumCapacity);
115 }
116
117 /**
130 value = Arrays.copyOf(value, newCapacity);
131 }
132
133 /**
134 * Attempts to reduce storage used for the character sequence.
135 * If the buffer is larger than necessary to hold its current sequence of
136 * characters, then it may be resized to become more space efficient.
137 * Calling this method may, but is not required to, affect the value
138 * returned by a subsequent call to the {@link #capacity()} method.
139 */
140 public void trimToSize() {
141 if (count < value.length) {
142 value = Arrays.copyOf(value, count);
143 }
144 }
145
146 /**
147 * Sets the length of the character sequence.
148 * The sequence is changed to a new character sequence
149 * whose length is specified by the argument. For every nonnegative
150 * index <i>k</i> less than <code>newLength</code>, the character at
151 * index <i>k</i> in the new character sequence is the same as the
152 * character at index <i>k</i> in the old sequence if <i>k</i> is less
153 * than the length of the old character sequence; otherwise, it is the
154 * null character <code>'\u0000'</code>.
155 *
156 * In other words, if the <code>newLength</code> argument is less than
157 * the current length, the length is changed to the specified length.
158 * <p>
159 * If the <code>newLength</code> argument is greater than or equal
160 * to the current length, sufficient null characters
161 * (<code>'\u0000'</code>) are appended so that
162 * length becomes the <code>newLength</code> argument.
163 * <p>
164 * The <code>newLength</code> argument must be greater than or equal
165 * to <code>0</code>.
166 *
167 * @param newLength the new length
168 * @throws IndexOutOfBoundsException if the
169 * <code>newLength</code> argument is negative.
170 */
171 public void setLength(int newLength) {
172 if (newLength < 0)
173 throw new StringIndexOutOfBoundsException(newLength);
174 ensureCapacityInternal(newLength);
175
176 if (count < newLength) {
177 for (; count < newLength; count++)
178 value[count] = '\0';
179 } else {
180 count = newLength;
181 }
182 }
183
184 /**
185 * Returns the <code>char</code> value in this sequence at the specified index.
186 * The first <code>char</code> value is at index <code>0</code>, the next at index
187 * <code>1</code>, and so on, as in array indexing.
188 * <p>
189 * The index argument must be greater than or equal to
190 * <code>0</code>, and less than the length of this sequence.
191 *
192 * <p>If the <code>char</code> value specified by the index is a
193 * <a href="Character.html#unicode">surrogate</a>, the surrogate
194 * value is returned.
195 *
196 * @param index the index of the desired <code>char</code> value.
197 * @return the <code>char</code> value at the specified index.
198 * @throws IndexOutOfBoundsException if <code>index</code> is
199 * negative or greater than or equal to <code>length()</code>.
200 */
201 public char charAt(int index) {
202 if ((index < 0) || (index >= count))
203 throw new StringIndexOutOfBoundsException(index);
204 return value[index];
205 }
206
207 /**
208 * Returns the character (Unicode code point) at the specified
209 * index. The index refers to <code>char</code> values
210 * (Unicode code units) and ranges from <code>0</code> to
211 * {@link #length()}<code> - 1</code>.
212 *
213 * <p> If the <code>char</code> value specified at the given index
214 * is in the high-surrogate range, the following index is less
215 * than the length of this sequence, and the
216 * <code>char</code> value at the following index is in the
217 * low-surrogate range, then the supplementary code point
218 * corresponding to this surrogate pair is returned. Otherwise,
219 * the <code>char</code> value at the given index is returned.
220 *
221 * @param index the index to the <code>char</code> values
222 * @return the code point value of the character at the
223 * <code>index</code>
224 * @exception IndexOutOfBoundsException if the <code>index</code>
225 * argument is negative or not less than the length of this
226 * sequence.
227 */
228 public int codePointAt(int index) {
229 if ((index < 0) || (index >= count)) {
230 throw new StringIndexOutOfBoundsException(index);
231 }
232 return Character.codePointAt(value, index);
233 }
234
235 /**
236 * Returns the character (Unicode code point) before the specified
237 * index. The index refers to <code>char</code> values
238 * (Unicode code units) and ranges from <code>1</code> to {@link
239 * #length()}.
240 *
241 * <p> If the <code>char</code> value at <code>(index - 1)</code>
242 * is in the low-surrogate range, <code>(index - 2)</code> is not
243 * negative, and the <code>char</code> value at <code>(index -
244 * 2)</code> is in the high-surrogate range, then the
245 * supplementary code point value of the surrogate pair is
246 * returned. If the <code>char</code> value at <code>index -
247 * 1</code> is an unpaired low-surrogate or a high-surrogate, the
248 * surrogate value is returned.
249 *
250 * @param index the index following the code point that should be returned
251 * @return the Unicode code point value before the given index.
252 * @exception IndexOutOfBoundsException if the <code>index</code>
253 * argument is less than 1 or greater than the length
254 * of this sequence.
255 */
256 public int codePointBefore(int index) {
257 int i = index - 1;
258 if ((i < 0) || (i >= count)) {
259 throw new StringIndexOutOfBoundsException(index);
260 }
261 return Character.codePointBefore(value, index);
262 }
263
264 /**
265 * Returns the number of Unicode code points in the specified text
266 * range of this sequence. The text range begins at the specified
267 * <code>beginIndex</code> and extends to the <code>char</code> at
268 * index <code>endIndex - 1</code>. Thus the length (in
269 * <code>char</code>s) of the text range is
270 * <code>endIndex-beginIndex</code>. Unpaired surrogates within
271 * this sequence count as one code point each.
272 *
273 * @param beginIndex the index to the first <code>char</code> of
274 * the text range.
275 * @param endIndex the index after the last <code>char</code> of
276 * the text range.
277 * @return the number of Unicode code points in the specified text
278 * range
279 * @exception IndexOutOfBoundsException if the
280 * <code>beginIndex</code> is negative, or <code>endIndex</code>
281 * is larger than the length of this sequence, or
282 * <code>beginIndex</code> is larger than <code>endIndex</code>.
283 */
284 public int codePointCount(int beginIndex, int endIndex) {
285 if (beginIndex < 0 || endIndex > count || beginIndex > endIndex) {
286 throw new IndexOutOfBoundsException();
287 }
288 return Character.codePointCountImpl(value, beginIndex, endIndex-beginIndex);
289 }
290
291 /**
292 * Returns the index within this sequence that is offset from the
293 * given <code>index</code> by <code>codePointOffset</code> code
294 * points. Unpaired surrogates within the text range given by
295 * <code>index</code> and <code>codePointOffset</code> count as
296 * one code point each.
297 *
298 * @param index the index to be offset
299 * @param codePointOffset the offset in code points
300 * @return the index within this sequence
301 * @exception IndexOutOfBoundsException if <code>index</code>
302 * is negative or larger then the length of this sequence,
303 * or if <code>codePointOffset</code> is positive and the subsequence
304 * starting with <code>index</code> has fewer than
305 * <code>codePointOffset</code> code points,
306 * or if <code>codePointOffset</code> is negative and the subsequence
307 * before <code>index</code> has fewer than the absolute value of
308 * <code>codePointOffset</code> code points.
309 */
310 public int offsetByCodePoints(int index, int codePointOffset) {
311 if (index < 0 || index > count) {
312 throw new IndexOutOfBoundsException();
313 }
314 return Character.offsetByCodePointsImpl(value, 0, count,
315 index, codePointOffset);
316 }
317
318 /**
319 * Characters are copied from this sequence into the
320 * destination character array <code>dst</code>. The first character to
321 * be copied is at index <code>srcBegin</code>; the last character to
322 * be copied is at index <code>srcEnd-1</code>. The total number of
323 * characters to be copied is <code>srcEnd-srcBegin</code>. The
324 * characters are copied into the subarray of <code>dst</code> starting
325 * at index <code>dstBegin</code> and ending at index:
326 * <p><blockquote><pre>
327 * dstbegin + (srcEnd-srcBegin) - 1
328 * </pre></blockquote>
329 *
330 * @param srcBegin start copying at this offset.
331 * @param srcEnd stop copying at this offset.
332 * @param dst the array to copy the data into.
333 * @param dstBegin offset into <code>dst</code>.
334 * @throws NullPointerException if <code>dst</code> is
335 * <code>null</code>.
336 * @throws IndexOutOfBoundsException if any of the following is true:
337 * <ul>
338 * <li><code>srcBegin</code> is negative
339 * <li><code>dstBegin</code> is negative
340 * <li>the <code>srcBegin</code> argument is greater than
341 * the <code>srcEnd</code> argument.
342 * <li><code>srcEnd</code> is greater than
343 * <code>this.length()</code>.
344 * <li><code>dstBegin+srcEnd-srcBegin</code> is greater than
345 * <code>dst.length</code>
346 * </ul>
347 */
348 public void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)
349 {
350 if (srcBegin < 0)
351 throw new StringIndexOutOfBoundsException(srcBegin);
352 if ((srcEnd < 0) || (srcEnd > count))
353 throw new StringIndexOutOfBoundsException(srcEnd);
354 if (srcBegin > srcEnd)
355 throw new StringIndexOutOfBoundsException("srcBegin > srcEnd");
356 System.arraycopy(value, srcBegin, dst, dstBegin, srcEnd - srcBegin);
357 }
358
359 /**
360 * The character at the specified index is set to <code>ch</code>. This
361 * sequence is altered to represent a new character sequence that is
362 * identical to the old character sequence, except that it contains the
363 * character <code>ch</code> at position <code>index</code>.
364 * <p>
365 * The index argument must be greater than or equal to
366 * <code>0</code>, and less than the length of this sequence.
367 *
368 * @param index the index of the character to modify.
369 * @param ch the new character.
370 * @throws IndexOutOfBoundsException if <code>index</code> is
371 * negative or greater than or equal to <code>length()</code>.
372 */
373 public void setCharAt(int index, char ch) {
374 if ((index < 0) || (index >= count))
375 throw new StringIndexOutOfBoundsException(index);
376 value[index] = ch;
377 }
378
379 /**
380 * Appends the string representation of the {@code Object} argument.
381 * <p>
382 * The overall effect is exactly as if the argument were converted
383 * to a string by the method {@link String#valueOf(Object)},
384 * and the characters of that string were then
385 * {@link #append(String) appended} to this character sequence.
386 *
387 * @param obj an {@code Object}.
388 * @return a reference to this object.
389 */
390 public AbstractStringBuilder append(Object obj) {
391 return append(String.valueOf(obj));
724 * {@code codePoint} isn't a valid Unicode code point
725 */
726 public AbstractStringBuilder appendCodePoint(int codePoint) {
727 final int count = this.count;
728
729 if (Character.isBmpCodePoint(codePoint)) {
730 ensureCapacityInternal(count + 1);
731 value[count] = (char) codePoint;
732 this.count = count + 1;
733 } else if (Character.isValidCodePoint(codePoint)) {
734 ensureCapacityInternal(count + 2);
735 Character.toSurrogates(codePoint, value, count);
736 this.count = count + 2;
737 } else {
738 throw new IllegalArgumentException();
739 }
740 return this;
741 }
742
743 /**
744 * Removes the <code>char</code> at the specified position in this
745 * sequence. This sequence is shortened by one <code>char</code>.
746 *
747 * <p>Note: If the character at the given index is a supplementary
748 * character, this method does not remove the entire character. If
749 * correct handling of supplementary characters is required,
750 * determine the number of <code>char</code>s to remove by calling
751 * <code>Character.charCount(thisSequence.codePointAt(index))</code>,
752 * where <code>thisSequence</code> is this sequence.
753 *
754 * @param index Index of <code>char</code> to remove
755 * @return This object.
756 * @throws StringIndexOutOfBoundsException if the <code>index</code>
757 * is negative or greater than or equal to
758 * <code>length()</code>.
759 */
760 public AbstractStringBuilder deleteCharAt(int index) {
761 if ((index < 0) || (index >= count))
762 throw new StringIndexOutOfBoundsException(index);
763 System.arraycopy(value, index+1, value, index, count-index-1);
764 count--;
765 return this;
766 }
767
768 /**
769 * Replaces the characters in a substring of this sequence
770 * with characters in the specified <code>String</code>. The substring
771 * begins at the specified <code>start</code> and extends to the character
772 * at index <code>end - 1</code> or to the end of the
773 * sequence if no such character exists. First the
774 * characters in the substring are removed and then the specified
775 * <code>String</code> is inserted at <code>start</code>. (This
776 * sequence will be lengthened to accommodate the
777 * specified String if necessary.)
778 *
779 * @param start The beginning index, inclusive.
780 * @param end The ending index, exclusive.
781 * @param str String that will replace previous contents.
782 * @return This object.
783 * @throws StringIndexOutOfBoundsException if <code>start</code>
784 * is negative, greater than <code>length()</code>, or
785 * greater than <code>end</code>.
786 */
787 public AbstractStringBuilder replace(int start, int end, String str) {
788 if (start < 0)
789 throw new StringIndexOutOfBoundsException(start);
790 if (start > count)
791 throw new StringIndexOutOfBoundsException("start > length()");
792 if (start > end)
793 throw new StringIndexOutOfBoundsException("start > end");
794
795 if (end > count)
796 end = count;
797 int len = str.length();
798 int newCount = count + len - (end - start);
799 ensureCapacityInternal(newCount);
800
801 System.arraycopy(value, end, value, start + len, count - end);
802 str.getChars(value, start);
803 count = newCount;
804 return this;
805 }
806
807 /**
808 * Returns a new <code>String</code> that contains a subsequence of
809 * characters currently contained in this character sequence. The
810 * substring begins at the specified index and extends to the end of
811 * this sequence.
812 *
813 * @param start The beginning index, inclusive.
814 * @return The new string.
815 * @throws StringIndexOutOfBoundsException if <code>start</code> is
816 * less than zero, or greater than the length of this object.
817 */
818 public String substring(int start) {
819 return substring(start, count);
820 }
821
822 /**
823 * Returns a new character sequence that is a subsequence of this sequence.
824 *
825 * <p> An invocation of this method of the form
826 *
827 * <blockquote><pre>
828 * sb.subSequence(begin, end)</pre></blockquote>
829 *
830 * behaves in exactly the same way as the invocation
831 *
832 * <blockquote><pre>
833 * sb.substring(begin, end)</pre></blockquote>
834 *
835 * This method is provided so that this class can
836 * implement the {@link CharSequence} interface. </p>
837 *
838 * @param start the start index, inclusive.
839 * @param end the end index, exclusive.
840 * @return the specified subsequence.
841 *
842 * @throws IndexOutOfBoundsException
843 * if <tt>start</tt> or <tt>end</tt> are negative,
844 * if <tt>end</tt> is greater than <tt>length()</tt>,
845 * or if <tt>start</tt> is greater than <tt>end</tt>
846 * @spec JSR-51
847 */
848 public CharSequence subSequence(int start, int end) {
849 return substring(start, end);
850 }
851
852 /**
853 * Returns a new <code>String</code> that contains a subsequence of
854 * characters currently contained in this sequence. The
855 * substring begins at the specified <code>start</code> and
856 * extends to the character at index <code>end - 1</code>.
857 *
858 * @param start The beginning index, inclusive.
859 * @param end The ending index, exclusive.
860 * @return The new string.
861 * @throws StringIndexOutOfBoundsException if <code>start</code>
862 * or <code>end</code> are negative or greater than
863 * <code>length()</code>, or <code>start</code> is
864 * greater than <code>end</code>.
865 */
866 public String substring(int start, int end) {
867 if (start < 0)
868 throw new StringIndexOutOfBoundsException(start);
869 if (end > count)
870 throw new StringIndexOutOfBoundsException(end);
871 if (start > end)
872 throw new StringIndexOutOfBoundsException(end - start);
873 return new String(value, start, end - start);
874 }
875
876 /**
877 * Inserts the string representation of a subarray of the {@code str}
878 * array argument into this sequence. The subarray begins at the
879 * specified {@code offset} and extends {@code len} {@code char}s.
880 * The characters of the subarray are inserted into this sequence at
881 * the position indicated by {@code index}. The length of this
882 * sequence increases by {@code len} {@code char}s.
883 *
884 * @param index position at which to insert subarray.
1237 * The {@code offset} argument must be greater than or equal to
1238 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1239 * of this sequence.
1240 *
1241 * @param offset the offset.
1242 * @param d a {@code double}.
1243 * @return a reference to this object.
1244 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1245 */
1246 public AbstractStringBuilder insert(int offset, double d) {
1247 return insert(offset, String.valueOf(d));
1248 }
1249
1250 /**
1251 * Returns the index within this string of the first occurrence of the
1252 * specified substring. The integer returned is the smallest value
1253 * <i>k</i> such that:
1254 * <blockquote><pre>
1255 * this.toString().startsWith(str, <i>k</i>)
1256 * </pre></blockquote>
1257 * is <code>true</code>.
1258 *
1259 * @param str any string.
1260 * @return if the string argument occurs as a substring within this
1261 * object, then the index of the first character of the first
1262 * such substring is returned; if it does not occur as a
1263 * substring, <code>-1</code> is returned.
1264 * @throws java.lang.NullPointerException if <code>str</code> is
1265 * <code>null</code>.
1266 */
1267 public int indexOf(String str) {
1268 return indexOf(str, 0);
1269 }
1270
1271 /**
1272 * Returns the index within this string of the first occurrence of the
1273 * specified substring, starting at the specified index. The integer
1274 * returned is the smallest value <tt>k</tt> for which:
1275 * <blockquote><pre>
1276 * k >= Math.min(fromIndex, str.length()) &&
1277 * this.toString().startsWith(str, k)
1278 * </pre></blockquote>
1279 * If no such value of <i>k</i> exists, then -1 is returned.
1280 *
1281 * @param str the substring for which to search.
1282 * @param fromIndex the index from which to start the search.
1283 * @return the index within this string of the first occurrence of the
1284 * specified substring, starting at the specified index.
1285 * @throws java.lang.NullPointerException if <code>str</code> is
1286 * <code>null</code>.
1287 */
1288 public int indexOf(String str, int fromIndex) {
1289 return String.indexOf(value, 0, count,
1290 str.toCharArray(), 0, str.length(), fromIndex);
1291 }
1292
1293 /**
1294 * Returns the index within this string of the rightmost occurrence
1295 * of the specified substring. The rightmost empty string "" is
1296 * considered to occur at the index value <code>this.length()</code>.
1297 * The returned index is the largest value <i>k</i> such that
1298 * <blockquote><pre>
1299 * this.toString().startsWith(str, k)
1300 * </pre></blockquote>
1301 * is true.
1302 *
1303 * @param str the substring to search for.
1304 * @return if the string argument occurs one or more times as a substring
1305 * within this object, then the index of the first character of
1306 * the last such substring is returned. If it does not occur as
1307 * a substring, <code>-1</code> is returned.
1308 * @throws java.lang.NullPointerException if <code>str</code> is
1309 * <code>null</code>.
1310 */
1311 public int lastIndexOf(String str) {
1312 return lastIndexOf(str, count);
1313 }
1314
1315 /**
1316 * Returns the index within this string of the last occurrence of the
1317 * specified substring. The integer returned is the largest value <i>k</i>
1318 * such that:
1319 * <blockquote><pre>
1320 * k <= Math.min(fromIndex, str.length()) &&
1321 * this.toString().startsWith(str, k)
1322 * </pre></blockquote>
1323 * If no such value of <i>k</i> exists, then -1 is returned.
1324 *
1325 * @param str the substring to search for.
1326 * @param fromIndex the index to start the search from.
1327 * @return the index within this sequence of the last occurrence of the
1328 * specified substring.
1329 * @throws java.lang.NullPointerException if <code>str</code> is
1330 * <code>null</code>.
1331 */
1332 public int lastIndexOf(String str, int fromIndex) {
1333 return String.lastIndexOf(value, 0, count,
1334 str.toCharArray(), 0, str.length(), fromIndex);
1335 }
1336
1337 /**
1338 * Causes this character sequence to be replaced by the reverse of
1339 * the sequence. If there are any surrogate pairs included in the
1340 * sequence, these are treated as single characters for the
1341 * reverse operation. Thus, the order of the high-low surrogates
1342 * is never reversed.
1343 *
1344 * Let <i>n</i> be the character length of this character sequence
1345 * (not the length in <code>char</code> values) just prior to
1346 * execution of the <code>reverse</code> method. Then the
1347 * character at index <i>k</i> in the new character sequence is
1348 * equal to the character at index <i>n-k-1</i> in the old
1349 * character sequence.
1350 *
1351 * <p>Note that the reverse operation may result in producing
1352 * surrogate pairs that were unpaired low-surrogates and
1353 * high-surrogates before the operation. For example, reversing
1354 * "\uDC00\uD800" produces "\uD800\uDC00" which is
1355 * a valid surrogate pair.
1356 *
1357 * @return a reference to this object.
1358 */
1359 public AbstractStringBuilder reverse() {
1360 boolean hasSurrogate = false;
1361 int n = count - 1;
1362 for (int j = (n-1) >> 1; j >= 0; --j) {
1363 char temp = value[j];
1364 char temp2 = value[n - j];
1365 if (!hasSurrogate) {
1366 hasSurrogate = (temp >= Character.MIN_SURROGATE && temp <= Character.MAX_SURROGATE)
1367 || (temp2 >= Character.MIN_SURROGATE && temp2 <= Character.MAX_SURROGATE);
1368 }
1369 value[j] = temp2;
1370 value[n - j] = temp;
1371 }
1372 if (hasSurrogate) {
1373 // Reverse back all valid surrogate pairs
1374 for (int i = 0; i < count - 1; i++) {
1375 char c2 = value[i];
1376 if (Character.isLowSurrogate(c2)) {
1377 char c1 = value[i + 1];
1378 if (Character.isHighSurrogate(c1)) {
1379 value[i++] = c1;
1380 value[i] = c2;
1381 }
1382 }
1383 }
1384 }
1385 return this;
1386 }
1387
1388 /**
1389 * Returns a string representing the data in this sequence.
1390 * A new <code>String</code> object is allocated and initialized to
1391 * contain the character sequence currently represented by this
1392 * object. This <code>String</code> is then returned. Subsequent
1393 * changes to this sequence do not affect the contents of the
1394 * <code>String</code>.
1395 *
1396 * @return a string representation of this sequence of characters.
1397 */
1398 public abstract String toString();
1399
1400 /**
1401 * Needed by <tt>String</tt> for the contentEquals method.
1402 */
1403 final char[] getValue() {
1404 return value;
1405 }
1406
1407 }
|
1 /*
2 * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
74 return count;
75 }
76
77 /**
78 * Returns the current capacity. The capacity is the amount of storage
79 * available for newly inserted characters, beyond which an allocation
80 * will occur.
81 *
82 * @return the current capacity
83 */
84 public int capacity() {
85 return value.length;
86 }
87
88 /**
89 * Ensures that the capacity is at least equal to the specified minimum.
90 * If the current capacity is less than the argument, then a new internal
91 * array is allocated with greater capacity. The new capacity is the
92 * larger of:
93 * <ul>
94 * <li>The {@code minimumCapacity} argument.
95 * <li>Twice the old capacity, plus {@code 2}.
96 * </ul>
97 * If the {@code minimumCapacity} argument is nonpositive, this
98 * method takes no action and simply returns.
99 *
100 * @param minimumCapacity the minimum desired capacity.
101 */
102 public void ensureCapacity(int minimumCapacity) {
103 if (minimumCapacity > 0)
104 ensureCapacityInternal(minimumCapacity);
105 }
106
107 /**
108 * This method has the same contract as ensureCapacity, but is
109 * never synchronized.
110 */
111 private void ensureCapacityInternal(int minimumCapacity) {
112 // overflow-conscious code
113 if (minimumCapacity - value.length > 0)
114 expandCapacity(minimumCapacity);
115 }
116
117 /**
130 value = Arrays.copyOf(value, newCapacity);
131 }
132
133 /**
134 * Attempts to reduce storage used for the character sequence.
135 * If the buffer is larger than necessary to hold its current sequence of
136 * characters, then it may be resized to become more space efficient.
137 * Calling this method may, but is not required to, affect the value
138 * returned by a subsequent call to the {@link #capacity()} method.
139 */
140 public void trimToSize() {
141 if (count < value.length) {
142 value = Arrays.copyOf(value, count);
143 }
144 }
145
146 /**
147 * Sets the length of the character sequence.
148 * The sequence is changed to a new character sequence
149 * whose length is specified by the argument. For every nonnegative
150 * index <i>k</i> less than {@code newLength}, the character at
151 * index <i>k</i> in the new character sequence is the same as the
152 * character at index <i>k</i> in the old sequence if <i>k</i> is less
153 * than the length of the old character sequence; otherwise, it is the
154 * null character {@code '\u005Cu0000'}.
155 *
156 * In other words, if the {@code newLength} argument is less than
157 * the current length, the length is changed to the specified length.
158 * <p>
159 * If the {@code newLength} argument is greater than or equal
160 * to the current length, sufficient null characters
161 * ({@code '\u005Cu0000'}) are appended so that
162 * length becomes the {@code newLength} argument.
163 * <p>
164 * The {@code newLength} argument must be greater than or equal
165 * to {@code 0}.
166 *
167 * @param newLength the new length
168 * @throws IndexOutOfBoundsException if the
169 * {@code newLength} argument is negative.
170 */
171 public void setLength(int newLength) {
172 if (newLength < 0)
173 throw new StringIndexOutOfBoundsException(newLength);
174 ensureCapacityInternal(newLength);
175
176 if (count < newLength) {
177 for (; count < newLength; count++)
178 value[count] = '\0';
179 } else {
180 count = newLength;
181 }
182 }
183
184 /**
185 * Returns the {@code char} value in this sequence at the specified index.
186 * The first {@code char} value is at index {@code 0}, the next at index
187 * {@code 1}, and so on, as in array indexing.
188 * <p>
189 * The index argument must be greater than or equal to
190 * {@code 0}, and less than the length of this sequence.
191 *
192 * <p>If the {@code char} value specified by the index is a
193 * <a href="Character.html#unicode">surrogate</a>, the surrogate
194 * value is returned.
195 *
196 * @param index the index of the desired {@code char} value.
197 * @return the {@code char} value at the specified index.
198 * @throws IndexOutOfBoundsException if {@code index} is
199 * negative or greater than or equal to {@code length()}.
200 */
201 public char charAt(int index) {
202 if ((index < 0) || (index >= count))
203 throw new StringIndexOutOfBoundsException(index);
204 return value[index];
205 }
206
207 /**
208 * Returns the character (Unicode code point) at the specified
209 * index. The index refers to {@code char} values
210 * (Unicode code units) and ranges from {@code 0} to
211 * {@link #length()}{@code - 1}.
212 *
213 * <p> If the {@code char} value specified at the given index
214 * is in the high-surrogate range, the following index is less
215 * than the length of this sequence, and the
216 * {@code char} value at the following index is in the
217 * low-surrogate range, then the supplementary code point
218 * corresponding to this surrogate pair is returned. Otherwise,
219 * the {@code char} value at the given index is returned.
220 *
221 * @param index the index to the {@code char} values
222 * @return the code point value of the character at the
223 * {@code index}
224 * @exception IndexOutOfBoundsException if the {@code index}
225 * argument is negative or not less than the length of this
226 * sequence.
227 */
228 public int codePointAt(int index) {
229 if ((index < 0) || (index >= count)) {
230 throw new StringIndexOutOfBoundsException(index);
231 }
232 return Character.codePointAt(value, index);
233 }
234
235 /**
236 * Returns the character (Unicode code point) before the specified
237 * index. The index refers to {@code char} values
238 * (Unicode code units) and ranges from {@code 1} to {@link
239 * #length()}.
240 *
241 * <p> If the {@code char} value at {@code (index - 1)}
242 * is in the low-surrogate range, {@code (index - 2)} is not
243 * negative, and the {@code char} value at {@code (index -
244 * 2)} is in the high-surrogate range, then the
245 * supplementary code point value of the surrogate pair is
246 * returned. If the {@code char} value at {@code index -
247 * 1} is an unpaired low-surrogate or a high-surrogate, the
248 * surrogate value is returned.
249 *
250 * @param index the index following the code point that should be returned
251 * @return the Unicode code point value before the given index.
252 * @exception IndexOutOfBoundsException if the {@code index}
253 * argument is less than 1 or greater than the length
254 * of this sequence.
255 */
256 public int codePointBefore(int index) {
257 int i = index - 1;
258 if ((i < 0) || (i >= count)) {
259 throw new StringIndexOutOfBoundsException(index);
260 }
261 return Character.codePointBefore(value, index);
262 }
263
264 /**
265 * Returns the number of Unicode code points in the specified text
266 * range of this sequence. The text range begins at the specified
267 * {@code beginIndex} and extends to the {@code char} at
268 * index {@code endIndex - 1}. Thus the length (in
269 * {@code char}s) of the text range is
270 * {@code endIndex-beginIndex}. Unpaired surrogates within
271 * this sequence count as one code point each.
272 *
273 * @param beginIndex the index to the first {@code char} of
274 * the text range.
275 * @param endIndex the index after the last {@code char} of
276 * the text range.
277 * @return the number of Unicode code points in the specified text
278 * range
279 * @exception IndexOutOfBoundsException if the
280 * {@code beginIndex} is negative, or {@code endIndex}
281 * is larger than the length of this sequence, or
282 * {@code beginIndex} is larger than {@code endIndex}.
283 */
284 public int codePointCount(int beginIndex, int endIndex) {
285 if (beginIndex < 0 || endIndex > count || beginIndex > endIndex) {
286 throw new IndexOutOfBoundsException();
287 }
288 return Character.codePointCountImpl(value, beginIndex, endIndex-beginIndex);
289 }
290
291 /**
292 * Returns the index within this sequence that is offset from the
293 * given {@code index} by {@code codePointOffset} code
294 * points. Unpaired surrogates within the text range given by
295 * {@code index} and {@code codePointOffset} count as
296 * one code point each.
297 *
298 * @param index the index to be offset
299 * @param codePointOffset the offset in code points
300 * @return the index within this sequence
301 * @exception IndexOutOfBoundsException if {@code index}
302 * is negative or larger then the length of this sequence,
303 * or if {@code codePointOffset} is positive and the subsequence
304 * starting with {@code index} has fewer than
305 * {@code codePointOffset} code points,
306 * or if {@code codePointOffset} is negative and the subsequence
307 * before {@code index} has fewer than the absolute value of
308 * {@code codePointOffset} code points.
309 */
310 public int offsetByCodePoints(int index, int codePointOffset) {
311 if (index < 0 || index > count) {
312 throw new IndexOutOfBoundsException();
313 }
314 return Character.offsetByCodePointsImpl(value, 0, count,
315 index, codePointOffset);
316 }
317
318 /**
319 * Characters are copied from this sequence into the
320 * destination character array {@code dst}. The first character to
321 * be copied is at index {@code srcBegin}; the last character to
322 * be copied is at index {@code srcEnd-1}. The total number of
323 * characters to be copied is {@code srcEnd-srcBegin}. The
324 * characters are copied into the subarray of {@code dst} starting
325 * at index {@code dstBegin} and ending at index:
326 * <p><blockquote><pre>
327 * dstbegin + (srcEnd-srcBegin) - 1
328 * </pre></blockquote>
329 *
330 * @param srcBegin start copying at this offset.
331 * @param srcEnd stop copying at this offset.
332 * @param dst the array to copy the data into.
333 * @param dstBegin offset into {@code dst}.
334 * @throws NullPointerException if {@code dst} is
335 * {@code null}.
336 * @throws IndexOutOfBoundsException if any of the following is true:
337 * <ul>
338 * <li>{@code srcBegin} is negative
339 * <li>{@code dstBegin} is negative
340 * <li>the {@code srcBegin} argument is greater than
341 * the {@code srcEnd} argument.
342 * <li>{@code srcEnd} is greater than
343 * {@code this.length()}.
344 * <li>{@code dstBegin+srcEnd-srcBegin} is greater than
345 * {@code dst.length}
346 * </ul>
347 */
348 public void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)
349 {
350 if (srcBegin < 0)
351 throw new StringIndexOutOfBoundsException(srcBegin);
352 if ((srcEnd < 0) || (srcEnd > count))
353 throw new StringIndexOutOfBoundsException(srcEnd);
354 if (srcBegin > srcEnd)
355 throw new StringIndexOutOfBoundsException("srcBegin > srcEnd");
356 System.arraycopy(value, srcBegin, dst, dstBegin, srcEnd - srcBegin);
357 }
358
359 /**
360 * The character at the specified index is set to {@code ch}. This
361 * sequence is altered to represent a new character sequence that is
362 * identical to the old character sequence, except that it contains the
363 * character {@code ch} at position {@code index}.
364 * <p>
365 * The index argument must be greater than or equal to
366 * {@code 0}, and less than the length of this sequence.
367 *
368 * @param index the index of the character to modify.
369 * @param ch the new character.
370 * @throws IndexOutOfBoundsException if {@code index} is
371 * negative or greater than or equal to {@code length()}.
372 */
373 public void setCharAt(int index, char ch) {
374 if ((index < 0) || (index >= count))
375 throw new StringIndexOutOfBoundsException(index);
376 value[index] = ch;
377 }
378
379 /**
380 * Appends the string representation of the {@code Object} argument.
381 * <p>
382 * The overall effect is exactly as if the argument were converted
383 * to a string by the method {@link String#valueOf(Object)},
384 * and the characters of that string were then
385 * {@link #append(String) appended} to this character sequence.
386 *
387 * @param obj an {@code Object}.
388 * @return a reference to this object.
389 */
390 public AbstractStringBuilder append(Object obj) {
391 return append(String.valueOf(obj));
724 * {@code codePoint} isn't a valid Unicode code point
725 */
726 public AbstractStringBuilder appendCodePoint(int codePoint) {
727 final int count = this.count;
728
729 if (Character.isBmpCodePoint(codePoint)) {
730 ensureCapacityInternal(count + 1);
731 value[count] = (char) codePoint;
732 this.count = count + 1;
733 } else if (Character.isValidCodePoint(codePoint)) {
734 ensureCapacityInternal(count + 2);
735 Character.toSurrogates(codePoint, value, count);
736 this.count = count + 2;
737 } else {
738 throw new IllegalArgumentException();
739 }
740 return this;
741 }
742
743 /**
744 * Removes the {@code char} at the specified position in this
745 * sequence. This sequence is shortened by one {@code char}.
746 *
747 * <p>Note: If the character at the given index is a supplementary
748 * character, this method does not remove the entire character. If
749 * correct handling of supplementary characters is required,
750 * determine the number of {@code char}s to remove by calling
751 * {@code Character.charCount(thisSequence.codePointAt(index))},
752 * where {@code thisSequence} is this sequence.
753 *
754 * @param index Index of {@code char} to remove
755 * @return This object.
756 * @throws StringIndexOutOfBoundsException if the {@code index}
757 * is negative or greater than or equal to
758 * {@code length()}.
759 */
760 public AbstractStringBuilder deleteCharAt(int index) {
761 if ((index < 0) || (index >= count))
762 throw new StringIndexOutOfBoundsException(index);
763 System.arraycopy(value, index+1, value, index, count-index-1);
764 count--;
765 return this;
766 }
767
768 /**
769 * Replaces the characters in a substring of this sequence
770 * with characters in the specified {@code String}. The substring
771 * begins at the specified {@code start} and extends to the character
772 * at index {@code end - 1} or to the end of the
773 * sequence if no such character exists. First the
774 * characters in the substring are removed and then the specified
775 * {@code String} is inserted at {@code start}. (This
776 * sequence will be lengthened to accommodate the
777 * specified String if necessary.)
778 *
779 * @param start The beginning index, inclusive.
780 * @param end The ending index, exclusive.
781 * @param str String that will replace previous contents.
782 * @return This object.
783 * @throws StringIndexOutOfBoundsException if {@code start}
784 * is negative, greater than {@code length()}, or
785 * greater than {@code end}.
786 */
787 public AbstractStringBuilder replace(int start, int end, String str) {
788 if (start < 0)
789 throw new StringIndexOutOfBoundsException(start);
790 if (start > count)
791 throw new StringIndexOutOfBoundsException("start > length()");
792 if (start > end)
793 throw new StringIndexOutOfBoundsException("start > end");
794
795 if (end > count)
796 end = count;
797 int len = str.length();
798 int newCount = count + len - (end - start);
799 ensureCapacityInternal(newCount);
800
801 System.arraycopy(value, end, value, start + len, count - end);
802 str.getChars(value, start);
803 count = newCount;
804 return this;
805 }
806
807 /**
808 * Returns a new {@code String} that contains a subsequence of
809 * characters currently contained in this character sequence. The
810 * substring begins at the specified index and extends to the end of
811 * this sequence.
812 *
813 * @param start The beginning index, inclusive.
814 * @return The new string.
815 * @throws StringIndexOutOfBoundsException if {@code start} is
816 * less than zero, or greater than the length of this object.
817 */
818 public String substring(int start) {
819 return substring(start, count);
820 }
821
822 /**
823 * Returns a new character sequence that is a subsequence of this sequence.
824 *
825 * <p> An invocation of this method of the form
826 *
827 * <blockquote><pre>
828 * sb.subSequence(begin, end)</pre></blockquote>
829 *
830 * behaves in exactly the same way as the invocation
831 *
832 * <blockquote><pre>
833 * sb.substring(begin, end)</pre></blockquote>
834 *
835 * This method is provided so that this class can
836 * implement the {@link CharSequence} interface. </p>
837 *
838 * @param start the start index, inclusive.
839 * @param end the end index, exclusive.
840 * @return the specified subsequence.
841 *
842 * @throws IndexOutOfBoundsException
843 * if <tt>start</tt> or <tt>end</tt> are negative,
844 * if <tt>end</tt> is greater than <tt>length()</tt>,
845 * or if <tt>start</tt> is greater than <tt>end</tt>
846 * @spec JSR-51
847 */
848 public CharSequence subSequence(int start, int end) {
849 return substring(start, end);
850 }
851
852 /**
853 * Returns a new {@code String} that contains a subsequence of
854 * characters currently contained in this sequence. The
855 * substring begins at the specified {@code start} and
856 * extends to the character at index {@code end - 1}.
857 *
858 * @param start The beginning index, inclusive.
859 * @param end The ending index, exclusive.
860 * @return The new string.
861 * @throws StringIndexOutOfBoundsException if {@code start}
862 * or {@code end} are negative or greater than
863 * {@code length()}, or {@code start} is
864 * greater than {@code end}.
865 */
866 public String substring(int start, int end) {
867 if (start < 0)
868 throw new StringIndexOutOfBoundsException(start);
869 if (end > count)
870 throw new StringIndexOutOfBoundsException(end);
871 if (start > end)
872 throw new StringIndexOutOfBoundsException(end - start);
873 return new String(value, start, end - start);
874 }
875
876 /**
877 * Inserts the string representation of a subarray of the {@code str}
878 * array argument into this sequence. The subarray begins at the
879 * specified {@code offset} and extends {@code len} {@code char}s.
880 * The characters of the subarray are inserted into this sequence at
881 * the position indicated by {@code index}. The length of this
882 * sequence increases by {@code len} {@code char}s.
883 *
884 * @param index position at which to insert subarray.
1237 * The {@code offset} argument must be greater than or equal to
1238 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1239 * of this sequence.
1240 *
1241 * @param offset the offset.
1242 * @param d a {@code double}.
1243 * @return a reference to this object.
1244 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1245 */
1246 public AbstractStringBuilder insert(int offset, double d) {
1247 return insert(offset, String.valueOf(d));
1248 }
1249
1250 /**
1251 * Returns the index within this string of the first occurrence of the
1252 * specified substring. The integer returned is the smallest value
1253 * <i>k</i> such that:
1254 * <blockquote><pre>
1255 * this.toString().startsWith(str, <i>k</i>)
1256 * </pre></blockquote>
1257 * is {@code true}.
1258 *
1259 * @param str any string.
1260 * @return if the string argument occurs as a substring within this
1261 * object, then the index of the first character of the first
1262 * such substring is returned; if it does not occur as a
1263 * substring, {@code -1} is returned.
1264 * @throws java.lang.NullPointerException if {@code str} is
1265 * {@code null}.
1266 */
1267 public int indexOf(String str) {
1268 return indexOf(str, 0);
1269 }
1270
1271 /**
1272 * Returns the index within this string of the first occurrence of the
1273 * specified substring, starting at the specified index. The integer
1274 * returned is the smallest value <tt>k</tt> for which:
1275 * <blockquote><pre>
1276 * k >= Math.min(fromIndex, str.length()) &&
1277 * this.toString().startsWith(str, k)
1278 * </pre></blockquote>
1279 * If no such value of <i>k</i> exists, then -1 is returned.
1280 *
1281 * @param str the substring for which to search.
1282 * @param fromIndex the index from which to start the search.
1283 * @return the index within this string of the first occurrence of the
1284 * specified substring, starting at the specified index.
1285 * @throws java.lang.NullPointerException if {@code str} is
1286 * {@code null}.
1287 */
1288 public int indexOf(String str, int fromIndex) {
1289 return String.indexOf(value, 0, count,
1290 str.toCharArray(), 0, str.length(), fromIndex);
1291 }
1292
1293 /**
1294 * Returns the index within this string of the rightmost occurrence
1295 * of the specified substring. The rightmost empty string "" is
1296 * considered to occur at the index value {@code this.length()}.
1297 * The returned index is the largest value <i>k</i> such that
1298 * <blockquote><pre>
1299 * this.toString().startsWith(str, k)
1300 * </pre></blockquote>
1301 * is true.
1302 *
1303 * @param str the substring to search for.
1304 * @return if the string argument occurs one or more times as a substring
1305 * within this object, then the index of the first character of
1306 * the last such substring is returned. If it does not occur as
1307 * a substring, {@code -1} is returned.
1308 * @throws java.lang.NullPointerException if {@code str} is
1309 * {@code null}.
1310 */
1311 public int lastIndexOf(String str) {
1312 return lastIndexOf(str, count);
1313 }
1314
1315 /**
1316 * Returns the index within this string of the last occurrence of the
1317 * specified substring. The integer returned is the largest value <i>k</i>
1318 * such that:
1319 * <blockquote><pre>
1320 * k <= Math.min(fromIndex, str.length()) &&
1321 * this.toString().startsWith(str, k)
1322 * </pre></blockquote>
1323 * If no such value of <i>k</i> exists, then -1 is returned.
1324 *
1325 * @param str the substring to search for.
1326 * @param fromIndex the index to start the search from.
1327 * @return the index within this sequence of the last occurrence of the
1328 * specified substring.
1329 * @throws java.lang.NullPointerException if {@code str} is
1330 * {@code null}.
1331 */
1332 public int lastIndexOf(String str, int fromIndex) {
1333 return String.lastIndexOf(value, 0, count,
1334 str.toCharArray(), 0, str.length(), fromIndex);
1335 }
1336
1337 /**
1338 * Causes this character sequence to be replaced by the reverse of
1339 * the sequence. If there are any surrogate pairs included in the
1340 * sequence, these are treated as single characters for the
1341 * reverse operation. Thus, the order of the high-low surrogates
1342 * is never reversed.
1343 *
1344 * Let <i>n</i> be the character length of this character sequence
1345 * (not the length in {@code char} values) just prior to
1346 * execution of the {@code reverse} method. Then the
1347 * character at index <i>k</i> in the new character sequence is
1348 * equal to the character at index <i>n-k-1</i> in the old
1349 * character sequence.
1350 *
1351 * <p>Note that the reverse operation may result in producing
1352 * surrogate pairs that were unpaired low-surrogates and
1353 * high-surrogates before the operation. For example, reversing
1354 * "\u005CuDC00\u005CuD800" produces "\u005CuD800\u005CuDC00" which is
1355 * a valid surrogate pair.
1356 *
1357 * @return a reference to this object.
1358 */
1359 public AbstractStringBuilder reverse() {
1360 boolean hasSurrogate = false;
1361 int n = count - 1;
1362 for (int j = (n-1) >> 1; j >= 0; --j) {
1363 char temp = value[j];
1364 char temp2 = value[n - j];
1365 if (!hasSurrogate) {
1366 hasSurrogate = (temp >= Character.MIN_SURROGATE && temp <= Character.MAX_SURROGATE)
1367 || (temp2 >= Character.MIN_SURROGATE && temp2 <= Character.MAX_SURROGATE);
1368 }
1369 value[j] = temp2;
1370 value[n - j] = temp;
1371 }
1372 if (hasSurrogate) {
1373 // Reverse back all valid surrogate pairs
1374 for (int i = 0; i < count - 1; i++) {
1375 char c2 = value[i];
1376 if (Character.isLowSurrogate(c2)) {
1377 char c1 = value[i + 1];
1378 if (Character.isHighSurrogate(c1)) {
1379 value[i++] = c1;
1380 value[i] = c2;
1381 }
1382 }
1383 }
1384 }
1385 return this;
1386 }
1387
1388 /**
1389 * Returns a string representing the data in this sequence.
1390 * A new {@code String} object is allocated and initialized to
1391 * contain the character sequence currently represented by this
1392 * object. This {@code String} is then returned. Subsequent
1393 * changes to this sequence do not affect the contents of the
1394 * {@code String}.
1395 *
1396 * @return a string representation of this sequence of characters.
1397 */
1398 public abstract String toString();
1399
1400 /**
1401 * Needed by <tt>String</tt> for the contentEquals method.
1402 */
1403 final char[] getValue() {
1404 return value;
1405 }
1406
1407 }
|