+ * 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); + 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); + 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) { + 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);
+ 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);
+
+ 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);
+ arraycopy(value, index, value, index + len, count - index);
+ 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); + 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); + arraycopy(value, offset, value, offset + len, count - offset); + 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);
+ 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);
+ 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];
+ arraycopy(original, from, copy, 0, Math.min(original.length - from, newLength));
+ return copy;
+ }
+
+ static void arraycopy(char[] value, int srcBegin, char[] dst, int dstBegin, int count) {
+ if (srcBegin < dstBegin) {
+ while (count-- > 0) {
+ dst[dstBegin + count] = value[srcBegin + count];
+ }
+ } else {
+ while (count-- > 0) {
+ dst[dstBegin++] = value[srcBegin++];
+ }
+ }
+ }
+
+ // access system property
+ static String getProperty(String nm) {
+ return null;
+ }
+
+ static char[] copyOf(char[] original, int newLength) {
+ char[] copy = new char[newLength];
+ arraycopy(original, 0, copy, 0, Math.min(original.length, newLength));
+ return copy;
+ }
+
+}