- * Implements a modifiable string. At any point in time it contains some - * particular sequence of characters, but the length and content of the - * sequence can be changed through certain method calls. - * - * @author Michael McCloskey - * @author Martin Buchholz - * @author Ulf Zibis - * @since 1.5 - */ -abstract class AbstractStringBuilder implements Appendable, CharSequence { - /** - * The value is used for character storage. - */ - char[] value; - - /** - * The count is the number of characters used. - */ - int count; - - /** - * This no-arg constructor is necessary for serialization of subclasses. - */ - AbstractStringBuilder() { - } - - /** - * Creates an AbstractStringBuilder of the specified capacity. - */ - AbstractStringBuilder(int capacity) { - value = new char[capacity]; - } - - /** - * Returns the length (character count). - * - * @return the length of the sequence of characters currently - * represented by this object - */ - public int length() { - return count; - } - - /** - * Returns the current capacity. The capacity is the amount of storage - * available for newly inserted characters, beyond which an allocation - * will occur. - * - * @return the current capacity - */ - public int capacity() { - return value.length; - } - - /** - * Ensures that the capacity is at least equal to the specified minimum. - * If the current capacity is less than the argument, then a new internal - * array is allocated with greater capacity. The new capacity is the - * larger of: - *
minimumCapacity argument.
- * 2.
- * minimumCapacity argument is nonpositive, this
- * method takes no action and simply returns.
- *
- * @param minimumCapacity the minimum desired capacity.
- */
- public void ensureCapacity(int minimumCapacity) {
- if (minimumCapacity > 0)
- ensureCapacityInternal(minimumCapacity);
- }
-
- /**
- * This method has the same contract as ensureCapacity, but is
- * never synchronized.
- */
- private void ensureCapacityInternal(int minimumCapacity) {
- // overflow-conscious code
- if (minimumCapacity - value.length > 0)
- expandCapacity(minimumCapacity);
- }
-
- /**
- * This implements the expansion semantics of ensureCapacity with no
- * size check or synchronization.
- */
- void expandCapacity(int minimumCapacity) {
- int newCapacity = value.length * 2 + 2;
- if (newCapacity - minimumCapacity < 0)
- newCapacity = minimumCapacity;
- if (newCapacity < 0) {
- if (minimumCapacity < 0) // overflow
- throw new OutOfMemoryError();
- newCapacity = Integer.MAX_VALUE;
- }
- value = copyOf(value, newCapacity);
- }
-
- /**
- * Attempts to reduce storage used for the character sequence.
- * If the buffer is larger than necessary to hold its current sequence of
- * characters, then it may be resized to become more space efficient.
- * Calling this method may, but is not required to, affect the value
- * returned by a subsequent call to the {@link #capacity()} method.
- */
- public void trimToSize() {
- if (count < value.length) {
- value = copyOf(value, count);
- }
- }
-
- /**
- * Sets the length of the character sequence.
- * The sequence is changed to a new character sequence
- * whose length is specified by the argument. For every nonnegative
- * index k less than newLength, the character at
- * index k in the new character sequence is the same as the
- * character at index k in the old sequence if k is less
- * than the length of the old character sequence; otherwise, it is the
- * null character '\u0000'.
- *
- * In other words, if the newLength argument is less than
- * the current length, the length is changed to the specified length.
- *
- * If the newLength argument is greater than or equal
- * to the current length, sufficient null characters
- * ('\u0000') are appended so that
- * length becomes the newLength argument.
- *
- * The newLength argument must be greater than or equal
- * to 0.
- *
- * @param newLength the new length
- * @throws IndexOutOfBoundsException if the
- * newLength argument is negative.
- */
- public void setLength(int newLength) {
- if (newLength < 0)
- throw new StringIndexOutOfBoundsException(newLength);
- ensureCapacityInternal(newLength);
-
- if (count < newLength) {
- for (; count < newLength; count++)
- value[count] = '\0';
- } else {
- count = newLength;
- }
- }
-
- /**
- * Returns the char value in this sequence at the specified index.
- * The first char value is at index 0, the next at index
- * 1, and so on, as in array indexing.
- *
- * The index argument must be greater than or equal to
- * 0, and less than the length of this sequence.
- *
- *
If the char value specified by the index is a
- * surrogate, the surrogate
- * value is returned.
- *
- * @param index the index of the desired char value.
- * @return the char value at the specified index.
- * @throws IndexOutOfBoundsException if index is
- * negative or greater than or equal to length().
- */
- public char charAt(int index) {
- if ((index < 0) || (index >= count))
- throw new StringIndexOutOfBoundsException(index);
- return value[index];
- }
-
- /**
- * Returns the character (Unicode code point) at the specified
- * index. The index refers to char values
- * (Unicode code units) and ranges from 0 to
- * {@link #length()} - 1.
- *
- *
If the char value specified at the given index
- * is in the high-surrogate range, the following index is less
- * than the length of this sequence, and the
- * char value at the following index is in the
- * low-surrogate range, then the supplementary code point
- * corresponding to this surrogate pair is returned. Otherwise,
- * the char value at the given index is returned.
- *
- * @param index the index to the char values
- * @return the code point value of the character at the
- * index
- * @exception IndexOutOfBoundsException if the index
- * argument is negative or not less than the length of this
- * sequence.
- */
- public int codePointAt(int index) {
- if ((index < 0) || (index >= count)) {
- throw new StringIndexOutOfBoundsException(index);
- }
- return Character.codePointAt(value, index);
- }
-
- /**
- * Returns the character (Unicode code point) before the specified
- * index. The index refers to char values
- * (Unicode code units) and ranges from 1 to {@link
- * #length()}.
- *
- *
If the char value at (index - 1)
- * is in the low-surrogate range, (index - 2) is not
- * negative, and the char value at (index -
- * 2) is in the high-surrogate range, then the
- * supplementary code point value of the surrogate pair is
- * returned. If the char value at index -
- * 1 is an unpaired low-surrogate or a high-surrogate, the
- * surrogate value is returned.
- *
- * @param index the index following the code point that should be returned
- * @return the Unicode code point value before the given index.
- * @exception IndexOutOfBoundsException if the index
- * argument is less than 1 or greater than the length
- * of this sequence.
- */
- public int codePointBefore(int index) {
- int i = index - 1;
- if ((i < 0) || (i >= count)) {
- throw new StringIndexOutOfBoundsException(index);
- }
- return Character.codePointBefore(value, index);
- }
-
- /**
- * Returns the number of Unicode code points in the specified text
- * range of this sequence. The text range begins at the specified
- * beginIndex and extends to the char at
- * index endIndex - 1. Thus the length (in
- * chars) of the text range is
- * endIndex-beginIndex. Unpaired surrogates within
- * this sequence count as one code point each.
- *
- * @param beginIndex the index to the first char of
- * the text range.
- * @param endIndex the index after the last char of
- * the text range.
- * @return the number of Unicode code points in the specified text
- * range
- * @exception IndexOutOfBoundsException if the
- * beginIndex is negative, or endIndex
- * is larger than the length of this sequence, or
- * beginIndex is larger than endIndex.
- */
- public int codePointCount(int beginIndex, int endIndex) {
- if (beginIndex < 0 || endIndex > count || beginIndex > endIndex) {
- throw new IndexOutOfBoundsException();
- }
- return Character.codePointCountImpl(value, beginIndex, endIndex-beginIndex);
- }
-
- /**
- * Returns the index within this sequence that is offset from the
- * given index by codePointOffset code
- * points. Unpaired surrogates within the text range given by
- * index and codePointOffset count as
- * one code point each.
- *
- * @param index the index to be offset
- * @param codePointOffset the offset in code points
- * @return the index within this sequence
- * @exception IndexOutOfBoundsException if index
- * is negative or larger then the length of this sequence,
- * or if codePointOffset is positive and the subsequence
- * starting with index has fewer than
- * codePointOffset code points,
- * or if codePointOffset is negative and the subsequence
- * before index has fewer than the absolute value of
- * codePointOffset code points.
- */
- public int offsetByCodePoints(int index, int codePointOffset) {
- if (index < 0 || index > count) {
- throw new IndexOutOfBoundsException();
- }
- return Character.offsetByCodePointsImpl(value, 0, count,
- index, codePointOffset);
- }
-
- /**
- * Characters are copied from this sequence into the
- * destination character array dst. The first character to
- * be copied is at index srcBegin; the last character to
- * be copied is at index srcEnd-1. The total number of
- * characters to be copied is srcEnd-srcBegin. The
- * characters are copied into the subarray of dst starting
- * at index dstBegin and ending at index:
- *
- * - * @param srcBegin start copying at this offset. - * @param srcEnd stop copying at this offset. - * @param dst the array to copy the data into. - * @param dstBegin offset into- * dstbegin + (srcEnd-srcBegin) - 1 - *
dst.
- * @throws NullPointerException if dst is
- * null.
- * @throws IndexOutOfBoundsException if any of the following is true:
- * srcBegin is negative
- * dstBegin is negative
- * srcBegin argument is greater than
- * the srcEnd argument.
- * srcEnd is greater than
- * this.length().
- * dstBegin+srcEnd-srcBegin is greater than
- * dst.length
- * ch. This
- * sequence is altered to represent a new character sequence that is
- * identical to the old character sequence, except that it contains the
- * character ch at position index.
- *
- * The index argument must be greater than or equal to
- * 0, and less than the length of this sequence.
- *
- * @param index the index of the character to modify.
- * @param ch the new character.
- * @throws IndexOutOfBoundsException if index is
- * negative or greater than or equal to length().
- */
- public void setCharAt(int index, char ch) {
- if ((index < 0) || (index >= count))
- throw new StringIndexOutOfBoundsException(index);
- value[index] = ch;
- }
-
- /**
- * Appends the string representation of the {@code Object} argument.
- *
- * The overall effect is exactly as if the argument were converted - * to a string by the method {@link String#valueOf(Object)}, - * and the characters of that string were then - * {@link #append(String) appended} to this character sequence. - * - * @param obj an {@code Object}. - * @return a reference to this object. - */ - public AbstractStringBuilder append(Object obj) { - return append(String.valueOf(obj)); - } - - /** - * Appends the specified string to this character sequence. - *
- * The characters of the {@code String} argument are appended, in - * order, increasing the length of this sequence by the length of the - * argument. If {@code str} is {@code null}, then the four - * characters {@code "null"} are appended. - *
- * Let n be the length of this character sequence just prior to - * execution of the {@code append} method. Then the character at - * index k in the new character sequence is equal to the character - * at index k in the old character sequence, if k is less - * than n; otherwise, it is equal to the character at index - * k-n in the argument {@code str}. - * - * @param str a string. - * @return a reference to this object. - */ - public AbstractStringBuilder append(String str) { - if (str == null) str = "null"; - int len = str.length(); - ensureCapacityInternal(count + len); - str.getChars(0, len, value, count); - count += len; - return this; - } - - // Documentation in subclasses because of synchro difference - public AbstractStringBuilder append(StringBuffer sb) { - if (sb == null) - return append("null"); - int len = sb.length(); - ensureCapacityInternal(count + len); - sb.getChars(0, len, value, count); - count += len; - return this; - } - - // Documentation in subclasses because of synchro difference - public AbstractStringBuilder append(CharSequence s) { - if (s == null) - s = "null"; - if (s instanceof String) - return this.append((String)s); - if (s instanceof StringBuffer) - return this.append((StringBuffer)s); - return this.append(s, 0, s.length()); - } - - /** - * Appends a subsequence of the specified {@code CharSequence} to this - * sequence. - *
- * Characters of the argument {@code s}, starting at - * index {@code start}, are appended, in order, to the contents of - * this sequence up to the (exclusive) index {@code end}. The length - * of this sequence is increased by the value of {@code end - start}. - *
- * Let n be the length of this character sequence just prior to - * execution of the {@code append} method. Then the character at - * index k in this character sequence becomes equal to the - * character at index k in this sequence, if k is less than - * n; otherwise, it is equal to the character at index - * k+start-n in the argument {@code s}. - *
- * If {@code s} is {@code null}, then this method appends - * characters as if the s parameter was a sequence containing the four - * characters {@code "null"}. - * - * @param s the sequence to append. - * @param start the starting index of the subsequence to be appended. - * @param end the end index of the subsequence to be appended. - * @return a reference to this object. - * @throws IndexOutOfBoundsException if - * {@code start} is negative, or - * {@code start} is greater than {@code end} or - * {@code end} is greater than {@code s.length()} - */ - public AbstractStringBuilder append(CharSequence s, int start, int end) { - if (s == null) - s = "null"; - if ((start < 0) || (start > end) || (end > s.length())) - throw new IndexOutOfBoundsException( - "start " + start + ", end " + end + ", s.length() " - + s.length()); - int len = end - start; - ensureCapacityInternal(count + len); - for (int i = start, j = count; i < end; i++, j++) - value[j] = s.charAt(i); - count += len; - return this; - } - - /** - * Appends the string representation of the {@code char} array - * argument to this sequence. - *
- * The characters of the array argument are appended, in order, to - * the contents of this sequence. The length of this sequence - * increases by the length of the argument. - *
- * The overall effect is exactly as if the argument were converted - * to a string by the method {@link String#valueOf(char[])}, - * and the characters of that string were then - * {@link #append(String) appended} to this character sequence. - * - * @param str the characters to be appended. - * @return a reference to this object. - */ - public AbstractStringBuilder append(char[] str) { - int len = str.length; - ensureCapacityInternal(count + len); - System.arraycopy(str, 0, value, count, len); - count += len; - return this; - } - - /** - * Appends the string representation of a subarray of the - * {@code char} array argument to this sequence. - *
- * Characters of the {@code char} array {@code str}, starting at - * index {@code offset}, are appended, in order, to the contents - * of this sequence. The length of this sequence increases - * by the value of {@code len}. - *
- * The overall effect is exactly as if the arguments were converted - * to a string by the method {@link String#valueOf(char[],int,int)}, - * and the characters of that string were then - * {@link #append(String) appended} to this character sequence. - * - * @param str the characters to be appended. - * @param offset the index of the first {@code char} to append. - * @param len the number of {@code char}s to append. - * @return a reference to this object. - * @throws IndexOutOfBoundsException - * if {@code offset < 0} or {@code len < 0} - * or {@code offset+len > str.length} - */ - public AbstractStringBuilder append(char str[], int offset, int len) { - if (len > 0) // let arraycopy report AIOOBE for len < 0 - ensureCapacityInternal(count + len); - System.arraycopy(str, offset, value, count, len); - count += len; - return this; - } - - /** - * Appends the string representation of the {@code boolean} - * argument to the sequence. - *
- * The overall effect is exactly as if the argument were converted - * to a string by the method {@link String#valueOf(boolean)}, - * and the characters of that string were then - * {@link #append(String) appended} to this character sequence. - * - * @param b a {@code boolean}. - * @return a reference to this object. - */ - public AbstractStringBuilder append(boolean b) { - if (b) { - ensureCapacityInternal(count + 4); - value[count++] = 't'; - value[count++] = 'r'; - value[count++] = 'u'; - value[count++] = 'e'; - } else { - ensureCapacityInternal(count + 5); - value[count++] = 'f'; - value[count++] = 'a'; - value[count++] = 'l'; - value[count++] = 's'; - value[count++] = 'e'; - } - return this; - } - - /** - * Appends the string representation of the {@code char} - * argument to this sequence. - *
- * The argument is appended to the contents of this sequence. - * The length of this sequence increases by {@code 1}. - *
- * The overall effect is exactly as if the argument were converted - * to a string by the method {@link String#valueOf(char)}, - * and the character in that string were then - * {@link #append(String) appended} to this character sequence. - * - * @param c a {@code char}. - * @return a reference to this object. - */ - public AbstractStringBuilder append(char c) { - ensureCapacityInternal(count + 1); - value[count++] = c; - return this; - } - - /** - * Appends the string representation of the {@code int} - * argument to this sequence. - *
- * The overall effect is exactly as if the argument were converted - * to a string by the method {@link String#valueOf(int)}, - * and the characters of that string were then - * {@link #append(String) appended} to this character sequence. - * - * @param i an {@code int}. - * @return a reference to this object. - */ - public AbstractStringBuilder append(int i) { - return append(Integer.toString(i)); - } - - /** - * Appends the string representation of the {@code long} - * argument to this sequence. - *
- * The overall effect is exactly as if the argument were converted - * to a string by the method {@link String#valueOf(long)}, - * and the characters of that string were then - * {@link #append(String) appended} to this character sequence. - * - * @param l a {@code long}. - * @return a reference to this object. - */ - public AbstractStringBuilder append(long l) { - if (l == Long.MIN_VALUE) { - append("-9223372036854775808"); - return this; - } - int appendedLength = (l < 0) ? Long.stringSize(-l) + 1 - : Long.stringSize(l); - int spaceNeeded = count + appendedLength; - ensureCapacityInternal(spaceNeeded); - Long.getChars(l, spaceNeeded, value); - count = spaceNeeded; - return this; - } - - /** - * Appends the string representation of the {@code float} - * argument to this sequence. - *
- * The overall effect is exactly as if the argument were converted - * to a string by the method {@link String#valueOf(float)}, - * and the characters of that string were then - * {@link #append(String) appended} to this character sequence. - * - * @param f a {@code float}. - * @return a reference to this object. - */ - public AbstractStringBuilder append(float f) { - return append(Float.toString(f)); - } - - /** - * Appends the string representation of the {@code double} - * argument to this sequence. - *
- * The overall effect is exactly as if the argument were converted - * to a string by the method {@link String#valueOf(double)}, - * and the characters of that string were then - * {@link #append(String) appended} to this character sequence. - * - * @param d a {@code double}. - * @return a reference to this object. - */ - public AbstractStringBuilder append(double d) { - return append(Double.toString(d)); - } - - /** - * Removes the characters in a substring of this sequence. - * The substring begins at the specified {@code start} and extends to - * the character at index {@code end - 1} or to the end of the - * sequence if no such character exists. If - * {@code start} is equal to {@code end}, no changes are made. - * - * @param start The beginning index, inclusive. - * @param end The ending index, exclusive. - * @return This object. - * @throws StringIndexOutOfBoundsException if {@code start} - * is negative, greater than {@code length()}, or - * greater than {@code end}. - */ - public AbstractStringBuilder delete(int start, int end) { - if (start < 0) - throw new StringIndexOutOfBoundsException(start); - if (end > count) - end = count; - if (start > end) - throw new StringIndexOutOfBoundsException(); - int len = end - start; - if (len > 0) { - System.arraycopy(value, start+len, value, start, count-end); - count -= len; - } - return this; - } - - /** - * Appends the string representation of the {@code codePoint} - * argument to this sequence. - * - *
The argument is appended to the contents of this sequence. - * The length of this sequence increases by - * {@link Character#charCount(int) Character.charCount(codePoint)}. - * - *
The overall effect is exactly as if the argument were
- * converted to a {@code char} array by the method
- * {@link Character#toChars(int)} and the character in that array
- * were then {@link #append(char[]) appended} to this character
- * sequence.
- *
- * @param codePoint a Unicode code point
- * @return a reference to this object.
- * @exception IllegalArgumentException if the specified
- * {@code codePoint} isn't a valid Unicode code point
- */
- public AbstractStringBuilder appendCodePoint(int codePoint) {
- final int count = this.count;
-
- if (Character.isBmpCodePoint(codePoint)) {
- ensureCapacityInternal(count + 1);
- value[count] = (char) codePoint;
- this.count = count + 1;
- } else if (Character.isValidCodePoint(codePoint)) {
- ensureCapacityInternal(count + 2);
- Character.toSurrogates(codePoint, value, count);
- this.count = count + 2;
- } else {
- throw new IllegalArgumentException();
- }
- return this;
- }
-
- /**
- * Removes the char at the specified position in this
- * sequence. This sequence is shortened by one char.
- *
- *
Note: If the character at the given index is a supplementary
- * character, this method does not remove the entire character. If
- * correct handling of supplementary characters is required,
- * determine the number of chars to remove by calling
- * Character.charCount(thisSequence.codePointAt(index)),
- * where thisSequence is this sequence.
- *
- * @param index Index of char to remove
- * @return This object.
- * @throws StringIndexOutOfBoundsException if the index
- * is negative or greater than or equal to
- * length().
- */
- public AbstractStringBuilder deleteCharAt(int index) {
- if ((index < 0) || (index >= count))
- throw new StringIndexOutOfBoundsException(index);
- System.arraycopy(value, index+1, value, index, count-index-1);
- count--;
- return this;
- }
-
- /**
- * Replaces the characters in a substring of this sequence
- * with characters in the specified String. The substring
- * begins at the specified start and extends to the character
- * at index end - 1 or to the end of the
- * sequence if no such character exists. First the
- * characters in the substring are removed and then the specified
- * String is inserted at start. (This
- * sequence will be lengthened to accommodate the
- * specified String if necessary.)
- *
- * @param start The beginning index, inclusive.
- * @param end The ending index, exclusive.
- * @param str String that will replace previous contents.
- * @return This object.
- * @throws StringIndexOutOfBoundsException if start
- * is negative, greater than length(), or
- * greater than end.
- */
- public AbstractStringBuilder replace(int start, int end, String str) {
- if (start < 0)
- throw new StringIndexOutOfBoundsException(start);
- if (start > count)
- throw new StringIndexOutOfBoundsException("start > length()");
- if (start > end)
- throw new StringIndexOutOfBoundsException("start > end");
-
- if (end > count)
- end = count;
- int len = str.length();
- int newCount = count + len - (end - start);
- ensureCapacityInternal(newCount);
-
- System.arraycopy(value, end, value, start + len, count - end);
- str.getChars(value, start);
- count = newCount;
- return this;
- }
-
- /**
- * Returns a new String that contains a subsequence of
- * characters currently contained in this character sequence. The
- * substring begins at the specified index and extends to the end of
- * this sequence.
- *
- * @param start The beginning index, inclusive.
- * @return The new string.
- * @throws StringIndexOutOfBoundsException if start is
- * less than zero, or greater than the length of this object.
- */
- public String substring(int start) {
- return substring(start, count);
- }
-
- /**
- * Returns a new character sequence that is a subsequence of this sequence.
- *
- *
An invocation of this method of the form - * - *
- * - * behaves in exactly the same way as the invocation - * - *- * sb.subSequence(begin, end)
- * - * This method is provided so that this class can - * implement the {@link CharSequence} interface. - * - * @param start the start index, inclusive. - * @param end the end index, exclusive. - * @return the specified subsequence. - * - * @throws IndexOutOfBoundsException - * if start or end are negative, - * if end is greater than length(), - * or if start is greater than end - * @spec JSR-51 - */ - public CharSequence subSequence(int start, int end) { - return substring(start, end); - } - - /** - * Returns a new- * sb.substring(begin, end)
String that contains a subsequence of
- * characters currently contained in this sequence. The
- * substring begins at the specified start and
- * extends to the character at index end - 1.
- *
- * @param start The beginning index, inclusive.
- * @param end The ending index, exclusive.
- * @return The new string.
- * @throws StringIndexOutOfBoundsException if start
- * or end are negative or greater than
- * length(), or start is
- * greater than end.
- */
- public String substring(int start, int end) {
- if (start < 0)
- throw new StringIndexOutOfBoundsException(start);
- if (end > count)
- throw new StringIndexOutOfBoundsException(end);
- if (start > end)
- throw new StringIndexOutOfBoundsException(end - start);
- return new String(value, start, end - start);
- }
-
- /**
- * Inserts the string representation of a subarray of the {@code str}
- * array argument into this sequence. The subarray begins at the
- * specified {@code offset} and extends {@code len} {@code char}s.
- * The characters of the subarray are inserted into this sequence at
- * the position indicated by {@code index}. The length of this
- * sequence increases by {@code len} {@code char}s.
- *
- * @param index position at which to insert subarray.
- * @param str A {@code char} array.
- * @param offset the index of the first {@code char} in subarray to
- * be inserted.
- * @param len the number of {@code char}s in the subarray to
- * be inserted.
- * @return This object
- * @throws StringIndexOutOfBoundsException if {@code index}
- * is negative or greater than {@code length()}, or
- * {@code offset} or {@code len} are negative, or
- * {@code (offset+len)} is greater than
- * {@code str.length}.
- */
- public AbstractStringBuilder insert(int index, char[] str, int offset,
- int len)
- {
- if ((index < 0) || (index > length()))
- throw new StringIndexOutOfBoundsException(index);
- if ((offset < 0) || (len < 0) || (offset > str.length - len))
- throw new StringIndexOutOfBoundsException(
- "offset " + offset + ", len " + len + ", str.length "
- + str.length);
- ensureCapacityInternal(count + len);
- System.arraycopy(value, index, value, index + len, count - index);
- System.arraycopy(str, offset, value, index, len);
- count += len;
- return this;
- }
-
- /**
- * Inserts the string representation of the {@code Object}
- * argument into this character sequence.
- * - * The overall effect is exactly as if the second argument were - * converted to a string by the method {@link String#valueOf(Object)}, - * and the characters of that string were then - * {@link #insert(int,String) inserted} into this character - * sequence at the indicated offset. - *
- * The {@code offset} argument must be greater than or equal to - * {@code 0}, and less than or equal to the {@linkplain #length() length} - * of this sequence. - * - * @param offset the offset. - * @param obj an {@code Object}. - * @return a reference to this object. - * @throws StringIndexOutOfBoundsException if the offset is invalid. - */ - public AbstractStringBuilder insert(int offset, Object obj) { - return insert(offset, String.valueOf(obj)); - } - - /** - * Inserts the string into this character sequence. - *
- * The characters of the {@code String} argument are inserted, in - * order, into this sequence at the indicated offset, moving up any - * characters originally above that position and increasing the length - * of this sequence by the length of the argument. If - * {@code str} is {@code null}, then the four characters - * {@code "null"} are inserted into this sequence. - *
- * The character at index k in the new character sequence is - * equal to: - *
- * The {@code offset} argument must be greater than or equal to - * {@code 0}, and less than or equal to the {@linkplain #length() length} - * of this sequence. - * - * @param offset the offset. - * @param str a string. - * @return a reference to this object. - * @throws StringIndexOutOfBoundsException if the offset is invalid. - */ - public AbstractStringBuilder insert(int offset, String str) { - if ((offset < 0) || (offset > length())) - throw new StringIndexOutOfBoundsException(offset); - if (str == null) - str = "null"; - int len = str.length(); - ensureCapacityInternal(count + len); - System.arraycopy(value, offset, value, offset + len, count - offset); - str.getChars(value, offset); - count += len; - return this; - } - - /** - * Inserts the string representation of the {@code char} array - * argument into this sequence. - *
- * The characters of the array argument are inserted into the - * contents of this sequence at the position indicated by - * {@code offset}. The length of this sequence increases by - * the length of the argument. - *
- * The overall effect is exactly as if the second argument were - * converted to a string by the method {@link String#valueOf(char[])}, - * and the characters of that string were then - * {@link #insert(int,String) inserted} into this character - * sequence at the indicated offset. - *
- * The {@code offset} argument must be greater than or equal to - * {@code 0}, and less than or equal to the {@linkplain #length() length} - * of this sequence. - * - * @param offset the offset. - * @param str a character array. - * @return a reference to this object. - * @throws StringIndexOutOfBoundsException if the offset is invalid. - */ - public AbstractStringBuilder insert(int offset, char[] str) { - if ((offset < 0) || (offset > length())) - throw new StringIndexOutOfBoundsException(offset); - int len = str.length; - ensureCapacityInternal(count + len); - System.arraycopy(value, offset, value, offset + len, count - offset); - System.arraycopy(str, 0, value, offset, len); - count += len; - return this; - } - - /** - * Inserts the specified {@code CharSequence} into this sequence. - *
- * The characters of the {@code CharSequence} argument are inserted, - * in order, into this sequence at the indicated offset, moving up - * any characters originally above that position and increasing the length - * of this sequence by the length of the argument s. - *
- * The result of this method is exactly the same as if it were an - * invocation of this object's - * {@link #insert(int,CharSequence,int,int) insert}(dstOffset, s, 0, s.length()) - * method. - * - *
If {@code s} is {@code null}, then the four characters - * {@code "null"} are inserted into this sequence. - * - * @param dstOffset the offset. - * @param s the sequence to be inserted - * @return a reference to this object. - * @throws IndexOutOfBoundsException if the offset is invalid. - */ - public AbstractStringBuilder insert(int dstOffset, CharSequence s) { - if (s == null) - s = "null"; - if (s instanceof String) - return this.insert(dstOffset, (String)s); - return this.insert(dstOffset, s, 0, s.length()); - } - - /** - * Inserts a subsequence of the specified {@code CharSequence} into - * this sequence. - *
- * The subsequence of the argument {@code s} specified by - * {@code start} and {@code end} are inserted, - * in order, into this sequence at the specified destination offset, moving - * up any characters originally above that position. The length of this - * sequence is increased by {@code end - start}. - *
- * The character at index k in this sequence becomes equal to: - *
- * The {@code dstOffset} argument must be greater than or equal to - * {@code 0}, and less than or equal to the {@linkplain #length() length} - * of this sequence. - *
The start argument must be nonnegative, and not greater than - * {@code end}. - *
The end argument must be greater than or equal to - * {@code start}, and less than or equal to the length of s. - * - *
If {@code s} is {@code null}, then this method inserts
- * characters as if the s parameter was a sequence containing the four
- * characters {@code "null"}.
- *
- * @param dstOffset the offset in this sequence.
- * @param s the sequence to be inserted.
- * @param start the starting index of the subsequence to be inserted.
- * @param end the end index of the subsequence to be inserted.
- * @return a reference to this object.
- * @throws IndexOutOfBoundsException if {@code dstOffset}
- * is negative or greater than {@code this.length()}, or
- * {@code start} or {@code end} are negative, or
- * {@code start} is greater than {@code end} or
- * {@code end} is greater than {@code s.length()}
- */
- public AbstractStringBuilder insert(int dstOffset, CharSequence s,
- int start, int end) {
- if (s == null)
- s = "null";
- if ((dstOffset < 0) || (dstOffset > this.length()))
- throw new IndexOutOfBoundsException("dstOffset "+dstOffset);
- if ((start < 0) || (end < 0) || (start > end) || (end > s.length()))
- throw new IndexOutOfBoundsException(
- "start " + start + ", end " + end + ", s.length() "
- + s.length());
- int len = end - start;
- ensureCapacityInternal(count + len);
- System.arraycopy(value, dstOffset, value, dstOffset + len,
- count - dstOffset);
- for (int i=start; i
- * The {@code offset} argument must be greater than or equal to
- * {@code 0}, and less than or equal to the {@linkplain #length() length}
- * of this sequence.
- *
- * @param offset the offset.
- * @param b a {@code boolean}.
- * @return a reference to this object.
- * @throws StringIndexOutOfBoundsException if the offset is invalid.
- */
- public AbstractStringBuilder insert(int offset, boolean b) {
- return insert(offset, String.valueOf(b));
- }
-
- /**
- * Inserts the string representation of the {@code char}
- * argument into this sequence.
- *
- * The overall effect is exactly as if the second argument were
- * converted to a string by the method {@link String#valueOf(char)},
- * and the character in that string were then
- * {@link #insert(int,String) inserted} into this character
- * sequence at the indicated offset.
- *
- * The {@code offset} argument must be greater than or equal to
- * {@code 0}, and less than or equal to the {@linkplain #length() length}
- * of this sequence.
- *
- * @param offset the offset.
- * @param c a {@code char}.
- * @return a reference to this object.
- * @throws IndexOutOfBoundsException if the offset is invalid.
- */
- public AbstractStringBuilder insert(int offset, char c) {
- ensureCapacityInternal(count + 1);
- System.arraycopy(value, offset, value, offset + 1, count - offset);
- value[offset] = c;
- count += 1;
- return this;
- }
-
- /**
- * Inserts the string representation of the second {@code int}
- * argument into this sequence.
- *
- * The overall effect is exactly as if the second argument were
- * converted to a string by the method {@link String#valueOf(int)},
- * and the characters of that string were then
- * {@link #insert(int,String) inserted} into this character
- * sequence at the indicated offset.
- *
- * The {@code offset} argument must be greater than or equal to
- * {@code 0}, and less than or equal to the {@linkplain #length() length}
- * of this sequence.
- *
- * @param offset the offset.
- * @param i an {@code int}.
- * @return a reference to this object.
- * @throws StringIndexOutOfBoundsException if the offset is invalid.
- */
- public AbstractStringBuilder insert(int offset, int i) {
- return insert(offset, String.valueOf(i));
- }
-
- /**
- * Inserts the string representation of the {@code long}
- * argument into this sequence.
- *
- * The overall effect is exactly as if the second argument were
- * converted to a string by the method {@link String#valueOf(long)},
- * and the characters of that string were then
- * {@link #insert(int,String) inserted} into this character
- * sequence at the indicated offset.
- *
- * The {@code offset} argument must be greater than or equal to
- * {@code 0}, and less than or equal to the {@linkplain #length() length}
- * of this sequence.
- *
- * @param offset the offset.
- * @param l a {@code long}.
- * @return a reference to this object.
- * @throws StringIndexOutOfBoundsException if the offset is invalid.
- */
- public AbstractStringBuilder insert(int offset, long l) {
- return insert(offset, String.valueOf(l));
- }
-
- /**
- * Inserts the string representation of the {@code float}
- * argument into this sequence.
- *
- * The overall effect is exactly as if the second argument were
- * converted to a string by the method {@link String#valueOf(float)},
- * and the characters of that string were then
- * {@link #insert(int,String) inserted} into this character
- * sequence at the indicated offset.
- *
- * The {@code offset} argument must be greater than or equal to
- * {@code 0}, and less than or equal to the {@linkplain #length() length}
- * of this sequence.
- *
- * @param offset the offset.
- * @param f a {@code float}.
- * @return a reference to this object.
- * @throws StringIndexOutOfBoundsException if the offset is invalid.
- */
- public AbstractStringBuilder insert(int offset, float f) {
- return insert(offset, String.valueOf(f));
- }
-
- /**
- * Inserts the string representation of the {@code double}
- * argument into this sequence.
- *
- * The overall effect is exactly as if the second argument were
- * converted to a string by the method {@link String#valueOf(double)},
- * and the characters of that string were then
- * {@link #insert(int,String) inserted} into this character
- * sequence at the indicated offset.
- *
- * The {@code offset} argument must be greater than or equal to
- * {@code 0}, and less than or equal to the {@linkplain #length() length}
- * of this sequence.
- *
- * @param offset the offset.
- * @param d a {@code double}.
- * @return a reference to this object.
- * @throws StringIndexOutOfBoundsException if the offset is invalid.
- */
- public AbstractStringBuilder insert(int offset, double d) {
- return insert(offset, String.valueOf(d));
- }
-
- /**
- * Returns the index within this string of the first occurrence of the
- * specified substring. The integer returned is the smallest value
- * k such that:
- * Note that the reverse operation may result in producing
- * surrogate pairs that were unpaired low-surrogates and
- * high-surrogates before the operation. For example, reversing
- * "\uDC00\uD800" produces "\uD800\uDC00" which is
- * a valid surrogate pair.
- *
- * @return a reference to this object.
- */
- public AbstractStringBuilder reverse() {
- boolean hasSurrogate = false;
- int n = count - 1;
- for (int j = (n-1) >> 1; j >= 0; --j) {
- char temp = value[j];
- char temp2 = value[n - j];
- if (!hasSurrogate) {
- hasSurrogate = (temp >= Character.MIN_SURROGATE && temp <= Character.MAX_SURROGATE)
- || (temp2 >= Character.MIN_SURROGATE && temp2 <= Character.MAX_SURROGATE);
- }
- value[j] = temp2;
- value[n - j] = temp;
- }
- if (hasSurrogate) {
- // Reverse back all valid surrogate pairs
- for (int i = 0; i < count - 1; i++) {
- char c2 = value[i];
- if (Character.isLowSurrogate(c2)) {
- char c1 = value[i + 1];
- if (Character.isHighSurrogate(c1)) {
- value[i++] = c1;
- value[i] = c2;
- }
- }
- }
- }
- return this;
- }
-
- /**
- * Returns a string representing the data in this sequence.
- * A new
- * is
- * this.toString().startsWith(str, k)
- *
true.
- *
- * @param str any string.
- * @return if the string argument occurs as a substring within this
- * object, then the index of the first character of the first
- * such substring is returned; if it does not occur as a
- * substring, -1 is returned.
- * @throws java.lang.NullPointerException if str is
- * null.
- */
- public int indexOf(String str) {
- return indexOf(str, 0);
- }
-
- /**
- * Returns the index within this string of the first occurrence of the
- * specified substring, starting at the specified index. The integer
- * returned is the smallest value k for which:
- *
- * If no such value of k exists, then -1 is returned.
- *
- * @param str the substring for which to search.
- * @param fromIndex the index from which to start the search.
- * @return the index within this string of the first occurrence of the
- * specified substring, starting at the specified index.
- * @throws java.lang.NullPointerException if
- * k >= Math.min(fromIndex, str.length()) &&
- * this.toString().startsWith(str, k)
- *
str is
- * null.
- */
- public int indexOf(String str, int fromIndex) {
- return toString().indexOf(str, fromIndex);
- }
-
- /**
- * Returns the index within this string of the rightmost occurrence
- * of the specified substring. The rightmost empty string "" is
- * considered to occur at the index value this.length().
- * The returned index is the largest value k such that
- *
- * is true.
- *
- * @param str the substring to search for.
- * @return if the string argument occurs one or more times as a substring
- * within this object, then the index of the first character of
- * the last such substring is returned. If it does not occur as
- * a substring,
- * this.toString().startsWith(str, k)
- *
-1 is returned.
- * @throws java.lang.NullPointerException if str is
- * null.
- */
- public int lastIndexOf(String str) {
- return lastIndexOf(str, count);
- }
-
- /**
- * Returns the index within this string of the last occurrence of the
- * specified substring. The integer returned is the largest value k
- * such that:
- *
- * If no such value of k exists, then -1 is returned.
- *
- * @param str the substring to search for.
- * @param fromIndex the index to start the search from.
- * @return the index within this sequence of the last occurrence of the
- * specified substring.
- * @throws java.lang.NullPointerException if
- * k <= Math.min(fromIndex, str.length()) &&
- * this.toString().startsWith(str, k)
- *
str is
- * null.
- */
- public int lastIndexOf(String str, int fromIndex) {
- return String.lastIndexOf(value, 0, count,
- str.toCharArray(), 0, str.length(), fromIndex);
- }
-
- /**
- * Causes this character sequence to be replaced by the reverse of
- * the sequence. If there are any surrogate pairs included in the
- * sequence, these are treated as single characters for the
- * reverse operation. Thus, the order of the high-low surrogates
- * is never reversed.
- *
- * Let n be the character length of this character sequence
- * (not the length in char values) just prior to
- * execution of the reverse method. Then the
- * character at index k in the new character sequence is
- * equal to the character at index n-k-1 in the old
- * character sequence.
- *
- * String object is allocated and initialized to
- * contain the character sequence currently represented by this
- * object. This String is then returned. Subsequent
- * changes to this sequence do not affect the contents of the
- * String.
- *
- * @return a string representation of this sequence of characters.
- */
- public abstract String toString();
-
- /**
- * Needed by String for the contentEquals method.
- */
- final char[] getValue() {
- return value;
- }
-
- static char[] copyOfRange(char[] original, int from, int to) {
- int newLength = to - from;
- if (newLength < 0) {
- throw new IllegalArgumentException(from + " > " + to);
- }
- char[] copy = new char[newLength];
- System.arraycopy(original, from, copy, 0, Math.min(original.length - from, newLength));
- return copy;
- }
-
- // access system property
- static String getProperty(String nm) {
- return null;
- }
-
- static char[] copyOf(char[] original, int newLength) {
- char[] copy = new char[newLength];
- System.arraycopy(original, 0, copy, 0, Math.min(original.length, newLength));
- return copy;
- }
-
-}