/*
* @(#)AbstractStringBuilder.java 1.12 04/07/16
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.lang;
import sun.misc.FloatingDecimal;
/**
* A mutable sequence of characters.
* <p>
* 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
* @version 1.12, 07/16/04
* @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:
* <ul>
* <li>The <code>minimumCapacity</code> argument.
* <li>Twice the old capacity, plus <code>2</code>.
* </ul>
* If the <code>minimumCapacity</code> argument is nonpositive, this
* method takes no action and simply returns.
*
* @param minimumCapacity the minimum desired capacity.
*/
public void ensureCapacity(int minimumCapacity) {
if (minimumCapacity > value.length) {
expandCapacity(minimumCapacity);
}
}
/**
* This implements the expansion semantics of ensureCapacity with no
* size check or synchronization.
*/
void expandCapacity(int minimumCapacity) {
int newCapacity = (value.length + 1) * 2;
if (newCapacity < 0) {
newCapacity = Integer.MAX_VALUE;
} else if (minimumCapacity > newCapacity) {
newCapacity = minimumCapacity;
}
char newValue[] = new char[newCapacity];
System.arraycopy(value, 0, newValue, 0, count);
value = newValue;
}
/**
* 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) {
char[] newValue = new char[count];
System.arraycopy(value, 0, newValue, 0, count);
this.value = newValue;
}
}
/**
* 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 <i>k</i> less than <code>newLength</code>, the character at
* index <i>k</i> in the new character sequence is the same as the
* character at index <i>k</i> in the old sequence if <i>k</i> is less
* than the length of the old character sequence; otherwise, it is the
* null character <code>'\u0000'</code>.
*
* In other words, if the <code>newLength</code> argument is less than
* the current length, the length is changed to the specified length.
* <p>
* If the <code>newLength</code> argument is greater than or equal
* to the current length, sufficient null characters
* (<code>'\u0000'</code>) are appended so that
* length becomes the <code>newLength</code> argument.
* <p>
* The <code>newLength</code> argument must be greater than or equal
* to <code>0</code>.
*
* @param newLength the new length
* @throws IndexOutOfBoundsException if the
* <code>newLength</code> argument is negative.
*/
public void setLength(int newLength) {
if (newLength < 0)
throw new StringIndexOutOfBoundsException(newLength);
if (newLength > value.length)
expandCapacity(newLength);
if (count < newLength) {
for (; count < newLength; count++)
value[count] = '\0';
} else {
count = newLength;
}
}
/**
* Returns the <code>char</code> value in this sequence at the specified index.
* The first <code>char</code> value is at index <code>0</code>, the next at index
* <code>1</code>, and so on, as in array indexing.
* <p>
* The index argument must be greater than or equal to
* <code>0</code>, and less than the length of this sequence.
*
* <p>If the <code>char</code> value specified by the index is a
* <a href="Character.html#unicode">surrogate</a>, the surrogate
* value is returned.
*
* @param index the index of the desired <code>char</code> value.
* @return the <code>char</code> value at the specified index.
* @throws IndexOutOfBoundsException if <code>index</code> is
* negative or greater than or equal to <code>length()</code>.
*/
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 <code>char</code> values
* (Unicode code units) and ranges from <code>0</code> to
* {@link #length()}<code> - 1</code>.
*
* <p> If the <code>char</code> 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
* <code>char</code> 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 <code>char</code> value at the given index is returned.
*
* @param index the index to the <code>char</code> values
* @return the code point value of the character at the
* <code>index</code>
* @exception IndexOutOfBoundsException if the <code>index</code>
* 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 <code>char</code> values
* (Unicode code units) and ranges from <code>1</code> to {@link
* #length()}.
*
* <p> If the <code>char</code> value at <code>(index - 1)</code>
* is in the low-surrogate range, <code>(index - 2)</code> is not
* negative, and the <code>char</code> value at <code>(index -
* 2)</code> is in the high-surrogate range, then the
* supplementary code point value of the surrogate pair is
* returned. If the <code>char</code> value at <code>index -
* 1</code> 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 <code>index</code>
* 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
* <code>beginIndex</code> and extends to the <code>char</code> at
* index <code>endIndex - 1</code>. Thus the length (in
* <code>char</code>s) of the text range is
* <code>endIndex-beginIndex</code>. Unpaired surrogates within
* this sequence count as one code point each.
*
* @param beginIndex the index to the first <code>char</code> of
* the text range.
* @param endIndex the index after the last <code>char</code> of
* the text range.
* @return the number of Unicode code points in the specified text
* range
* @exception IndexOutOfBoundsException if the
* <code>beginIndex</code> is negative, or <code>endIndex</code>
* is larger than the length of this sequence, or
* <code>beginIndex</code> is larger than <code>endIndex</code>.
*/
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 <code>index</code> by <code>codePointOffset</code> code
* points. Unpaired surrogates within the text range given by
* <code>index</code> and <code>codePointOffset</code> 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 <code>index</code>
* is negative or larger then the length of this sequence,
* or if <code>codePointOffset</code> is positive and the subsequence
* starting with <code>index</code> has fewer than
* <code>codePointOffset</code> code points,
* or if <code>codePointOffset</code> is negative and the subsequence
* before <code>index</code> has fewer than the absolute value of
* <code>codePointOffset</code> 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 <code>dst</code>. The first character to
* be copied is at index <code>srcBegin</code>; the last character to
* be copied is at index <code>srcEnd-1</code>. The total number of
* characters to be copied is <code>srcEnd-srcBegin</code>. The
* characters are copied into the subarray of <code>dst</code> starting
* at index <code>dstBegin</code> and ending at index:
* <p><blockquote><pre>
* dstbegin + (srcEnd-srcBegin) - 1
* </pre></blockquote>
*
* @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 <code>dst</code>.
* @throws NullPointerException if <code>dst</code> is
* <code>null</code>.
* @throws IndexOutOfBoundsException if any of the following is true:
* <ul>
* <li><code>srcBegin</code> is negative
* <li><code>dstBegin</code> is negative
* <li>the <code>srcBegin</code> argument is greater than
* the <code>srcEnd</code> argument.
* <li><code>srcEnd</code> is greater than
* <code>this.length()</code>.
* <li><code>dstBegin+srcEnd-srcBegin</code> is greater than
* <code>dst.length</code>
* </ul>
*/
public void getChars(int srcBegin, int srcEnd, char dst[],
int dstBegin)
{
if (srcBegin < 0)
throw new StringIndexOutOfBoundsException(srcBegin);
if ((srcEnd < 0) || (srcEnd > count))
throw new StringIndexOutOfBoundsException(srcEnd);
if (srcBegin > srcEnd)
throw new StringIndexOutOfBoundsException("srcBegin > srcEnd");
System.arraycopy(value, srcBegin, dst, dstBegin, srcEnd - srcBegin);
}
/**
* The character at the specified index is set to <code>ch</code>. This
* sequence is altered to represent a new character sequence that is
* identical to the old character sequence, except that it contains the
* character <code>ch</code> at position <code>index</code>.
* <p>
* The index argument must be greater than or equal to
* <code>0</code>, 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 <code>index</code> is
* negative or greater than or equal to <code>length()</code>.
*/
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</code>
* argument.
* <p>
* The argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then appended to this sequence.
*
* @param obj an <code>Object</code>.
* @return a reference to this object.
*/
public AbstractStringBuilder append(Object obj) {
return append(String.valueOf(obj));
}
/**
* Appends the specified string to this character sequence.
* <p>
* The characters of the <code>String</code> argument are appended, in
* order, increasing the length of this sequence by the length of the
* argument. If <code>str</code> is <code>null</code>, then the four
* characters <code>"null"</code> are appended.
* <p>
* Let <i>n</i> be the length of this character sequence just prior to
* execution of the <code>append</code> method. Then the character at
* index <i>k</i> in the new character sequence is equal to the character
* at index <i>k</i> in the old character sequence, if <i>k</i> is less
* than <i>n</i>; otherwise, it is equal to the character at index
* <i>k-n</i> in the argument <code>str</code>.
*
* @param str a string.
* @return a reference to this object.
*/
public AbstractStringBuilder append(String str) {
if (str == null) str = "null";
int len = str.length();
if (len == 0) return this;
int newCount = count + len;
if (newCount > value.length)
expandCapacity(newCount);
str.getChars(0, len, value, count);
count = newCount;
return this;
}
// Documentation in subclasses because of synchro difference
public AbstractStringBuilder append(StringBuffer sb) {
if (sb == null)
return append("null");
int len = sb.length();
int newCount = count + len;
if (newCount > value.length)
expandCapacity(newCount);
sb.getChars(0, len, value, count);
count = newCount;
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</code> to this
* sequence.
* <p>
* Characters of the argument <code>s</code>, starting at
* index <code>start</code>, are appended, in order, to the contents of
* this sequence up to the (exclusive) index <code>end</code>. The length
* of this sequence is increased by the value of <code>end - start</code>.
* <p>
* Let <i>n</i> be the length of this character sequence just prior to
* execution of the <code>append</code> method. Then the character at
* index <i>k</i> in this character sequence becomes equal to the
* character at index <i>k</i> in this sequence, if <i>k</i> is less than
* <i>n</i>; otherwise, it is equal to the character at index
* <i>k+start-n</i> in the argument <code>s</code>.
* <p>
* If <code>s</code> is <code>null</code>, then this method appends
* characters as if the s parameter was a sequence containing the four
* characters <code>"null"</code>.
*
* @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</code> or <code>end</code> are negative, or
* <code>start</code> is greater than <code>end</code> or
* <code>end</code> is greater than <code>s.length()</code>
*/
public AbstractStringBuilder append(CharSequence s, int start, int end) {
if (s == null)
s = "null";
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;
if (len == 0)
return this;
int newCount = count + len;
if (newCount > value.length)
expandCapacity(newCount);
for (int i=start; i<end; i++)
value[count++] = s.charAt(i);
count = newCount;
return this;
}
/**
* Appends the string representation of the <code>char</code> array
* argument to this sequence.
* <p>
* 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.
* <p>
* 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 newCount = count + str.length;
if (newCount > value.length)
expandCapacity(newCount);
System.arraycopy(str, 0, value, count, str.length);
count = newCount;
return this;
}
/**
* Appends the string representation of a subarray of the
* <code>char</code> array argument to this sequence.
* <p>
* Characters of the <code>char</code> array <code>str</code>, starting at
* index <code>offset</code>, are appended, in order, to the contents
* of this sequence. The length of this sequence increases
* by the value of <code>len</code>.
* <p>
* 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</code> to append.
* @param len the number of <code>char</code>s to append.
* @return a reference to this object.
*/
public AbstractStringBuilder append(char str[], int offset, int len) {
int newCount = count + len;
if (newCount > value.length)
expandCapacity(newCount);
System.arraycopy(str, offset, value, count, len);
count = newCount;
return this;
}
/**
* Appends the string representation of the <code>boolean</code>
* argument to the sequence.
* <p>
* The argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then appended to this sequence.
*
* @param b a <code>boolean</code>.
* @return a reference to this object.
*/
public AbstractStringBuilder append(boolean b) {
if (b) {
int newCount = count + 4;
if (newCount > value.length)
expandCapacity(newCount);
value[count++] = 't';
value[count++] = 'r';
value[count++] = 'u';
value[count++] = 'e';
} else {
int newCount = count + 5;
if (newCount > value.length)
expandCapacity(newCount);
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</code>
* argument to this sequence.
* <p>
* The argument is appended to the contents of this sequence.
* The length of this sequence increases by <code>1</code>.
* <p>
* 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</code>.
* @return a reference to this object.
*/
public AbstractStringBuilder append(char c) {
int newCount = count + 1;
if (newCount > value.length)
expandCapacity(newCount);
value[count++] = c;
return this;
}
/**
* Appends the string representation of the <code>int</code>
* argument to this sequence.
* <p>
* The argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then appended to this sequence.
*
* @param i an <code>int</code>.
* @return a reference to this object.
*/
public AbstractStringBuilder append(int i) {
if (i == Integer.MIN_VALUE) {
append("-2147483648");
return this;
}
int appendedLength = (i < 0) ? stringSizeOfInt(-i) + 1
: stringSizeOfInt(i);
int spaceNeeded = count + appendedLength;
if (spaceNeeded > value.length)
expandCapacity(spaceNeeded);
Integer.getChars(i, spaceNeeded, value);
count = spaceNeeded;
return this;
}
final static int [] sizeTable = { 9, 99, 999, 9999, 99999, 999999, 9999999,
99999999, 999999999, Integer.MAX_VALUE };
// Requires positive x
static int stringSizeOfInt(int x) {
for (int i=0; ; i++)
if (x <= sizeTable[i])
return i+1;
}
/**
* Appends the string representation of the <code>long</code>
* argument to this sequence.
* <p>
* The argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then appended to this sequence.
*
* @param l a <code>long</code>.
* @return a reference to this object.
*/
public AbstractStringBuilder append(long l) {
if (l == Long.MIN_VALUE) {
append("-9223372036854775808");
return this;
}
int appendedLength = (l < 0) ? stringSizeOfLong(-l) + 1
: stringSizeOfLong(l);
int spaceNeeded = count + appendedLength;
if (spaceNeeded > value.length)
expandCapacity(spaceNeeded);
Long.getChars(l, spaceNeeded, value);
count = spaceNeeded;
return this;
}
// Requires positive x
static int stringSizeOfLong(long x) {
long p = 10;
for (int i=1; i<19; i++) {
if (x < p)
return i;
p = 10*p;
}
return 19;
}
/**
* Appends the string representation of the <code>float</code>
* argument to this sequence.
* <p>
* The argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then appended to this string sequence.
*
* @param f a <code>float</code>.
* @return a reference to this object.
*/
public AbstractStringBuilder append(float f) {
new FloatingDecimal(f).appendTo(this);
return this;
}
/**
* Appends the string representation of the <code>double</code>
* argument to this sequence.
* <p>
* The argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then appended to this sequence.
*
* @param d a <code>double</code>.
* @return a reference to this object.
*/
public AbstractStringBuilder append(double d) {
new FloatingDecimal(d).appendTo(this);
return this;
}
/**
* Removes the characters in a substring of this sequence.
* The substring begins at the specified <code>start</code> and extends to
* the character at index <code>end - 1</code> or to the end of the
* sequence if no such character exists. If
* <code>start</code> is equal to <code>end</code>, no changes are made.
*
* @param start The beginning index, inclusive.
* @param end The ending index, exclusive.
* @return This object.
* @throws StringIndexOutOfBoundsException if <code>start</code>
* is negative, greater than <code>length()</code>, or
* greater than <code>end</code>.
*/
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</code>
* argument to this sequence.
*
* <p> The argument is appended to the contents of this sequence.
* The length of this sequence increases by
* {@link Character#charCount(int) Character.charCount(codePoint)}.
*
* <p> The overall effect is exactly as if the argument were
* converted to a <code>char</code> 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</code> isn't a valid Unicode code point
*/
public AbstractStringBuilder appendCodePoint(int codePoint) {
if (!Character.isValidCodePoint(codePoint)) {
throw new IllegalArgumentException();
}
int n = 1;
if (codePoint >= Character.MIN_SUPPLEMENTARY_CODE_POINT) {
n++;
}
int newCount = count + n;
if (newCount > value.length) {
expandCapacity(newCount);
}
if (n == 1) {
value[count++] = (char) codePoint;
} else {
Character.toSurrogates(codePoint, value, count);
count += n;
}
return this;
}
/**
* Removes the <code>char</code> at the specified position in this
* sequence. This sequence is shortened by one <code>char</code>.
*
* <p>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 <code>char</code>s to remove by calling
* <code>Character.charCount(thisSequence.codePointAt(index))</code>,
* where <code>thisSequence</code> is this sequence.
*
* @param index Index of <code>char</code> to remove
* @return This object.
* @throws StringIndexOutOfBoundsException if the <code>index</code>
* is negative or greater than or equal to
* <code>length()</code>.
*/
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 <code>String</code>. The substring
* begins at the specified <code>start</code> and extends to the character
* at index <code>end - 1</code> or to the end of the
* sequence if no such character exists. First the
* characters in the substring are removed and then the specified
* <code>String</code> is inserted at <code>start</code>. (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 <code>start</code>
* is negative, greater than <code>length()</code>, or
* greater than <code>end</code>.
*/
public AbstractStringBuilder replace(int start, int end, String str) {
if (start < 0)
throw new StringIndexOutOfBoundsException(start);
if (end > count)
end = count;
if (start > end)
throw new StringIndexOutOfBoundsException("start > end");
int len = str.length();
int newCount = count + len - (end - start);
if (newCount > value.length)
expandCapacity(newCount);
System.arraycopy(value, end, value, start + len, count - end);
str.getChars(value, start);
count = newCount;
return this;
}
/**
* Returns a new <code>String</code> 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 <code>start</code> 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.
*
* <p> An invocation of this method of the form
*
* <blockquote><pre>
* sb.subSequence(begin, end)</pre></blockquote>
*
* behaves in exactly the same way as the invocation
*
* <blockquote><pre>
* sb.substring(begin, end)</pre></blockquote>
*
* This method is provided so that this class can
* implement the {@link CharSequence} interface. </p>
*
* @param start the start index, inclusive.
* @param end the end index, exclusive.
* @return the specified subsequence.
*
* @throws IndexOutOfBoundsException
* if <tt>start</tt> or <tt>end</tt> are negative,
* if <tt>end</tt> is greater than <tt>length()</tt>,
* or if <tt>start</tt> is greater than <tt>end</tt>
* @spec JSR-51
*/
public CharSequence subSequence(int start, int end) {
return substring(start, end);
}
/**
* Returns a new <code>String</code> that contains a subsequence of
* characters currently contained in this sequence. The
* substring begins at the specified <code>start</code> and
* extends to the character at index <code>end - 1</code>.
*
* @param start The beginning index, inclusive.
* @param end The ending index, exclusive.
* @return The new string.
* @throws StringIndexOutOfBoundsException if <code>start</code>
* or <code>end</code> are negative or greater than
* <code>length()</code>, or <code>start</code> is
* greater than <code>end</code>.
*/
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</code>
* array argument into this sequence. The subarray begins at the
* specified <code>offset</code> and extends <code>len</code> <code>char</code>s.
* The characters of the subarray are inserted into this sequence at
* the position indicated by <code>index</code>. The length of this
* sequence increases by <code>len</code> <code>char</code>s.
*
* @param index position at which to insert subarray.
* @param str A <code>char</code> array.
* @param offset the index of the first <code>char</code> in subarray to
* be inserted.
* @param len the number of <code>char</code>s in the subarray to
* be inserted.
* @return This object
* @throws StringIndexOutOfBoundsException if <code>index</code>
* is negative or greater than <code>length()</code>, or
* <code>offset</code> or <code>len</code> are negative, or
* <code>(offset+len)</code> is greater than
* <code>str.length</code>.
*/
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);
int newCount = count + len;
if (newCount > value.length)
expandCapacity(newCount);
System.arraycopy(value, index, value, index + len, count - index);
System.arraycopy(str, offset, value, index, len);
count = newCount;
return this;
}
/**
* Inserts the string representation of the <code>Object</code>
* argument into this character sequence.
* <p>
* The second argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then inserted into this sequence at the indicated
* offset.
* <p>
* The offset argument must be greater than or equal to
* <code>0</code>, and less than or equal to the length of this
* sequence.
*
* @param offset the offset.
* @param obj an <code>Object</code>.
* @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.
* <p>
* The characters of the <code>String</code> 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</code> is <code>null</code>, then the four characters
* <code>"null"</code> are inserted into this sequence.
* <p>
* The character at index <i>k</i> in the new character sequence is
* equal to:
* <ul>
* <li>the character at index <i>k</i> in the old character sequence, if
* <i>k</i> is less than <code>offset</code>
* <li>the character at index <i>k</i><code>-offset</code> in the
* argument <code>str</code>, if <i>k</i> is not less than
* <code>offset</code> but is less than <code>offset+str.length()</code>
* <li>the character at index <i>k</i><code>-str.length()</code> in the
* old character sequence, if <i>k</i> is not less than
* <code>offset+str.length()</code>
* </ul><p>
* The offset argument must be greater than or equal to
* <code>0</code>, and less than or equal to the 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();
int newCount = count + len;
if (newCount > value.length)
expandCapacity(newCount);
System.arraycopy(value, offset, value, offset + len, count - offset);
str.getChars(value, offset);
count = newCount;
return this;
}
/**
* Inserts the string representation of the <code>char</code> array
* argument into this sequence.
* <p>
* The characters of the array argument are inserted into the
* contents of this sequence at the position indicated by
* <code>offset</code>. The length of this sequence increases by
* the length of the argument.
* <p>
* 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 #insert(int,String) inserted} into this
* character sequence at the position indicated by
* <code>offset</code>.
*
* @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;
int newCount = count + len;
if (newCount > value.length)
expandCapacity(newCount);
System.arraycopy(value, offset, value, offset + len, count - offset);
System.arraycopy(str, 0, value, offset, len);
count = newCount;
return this;
}
/**
* Inserts the specified <code>CharSequence</code> into this sequence.
* <p>
* The characters of the <code>CharSequence</code> 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.
* <p>
* The result of this method is exactly the same as if it were an
* invocation of this object's insert(dstOffset, s, 0, s.length()) method.
*
* <p>If <code>s</code> is <code>null</code>, then the four characters
* <code>"null"</code> 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</code> into
* this sequence.
* <p>
* The subsequence of the argument <code>s</code> specified by
* <code>start</code> and <code>end</code> 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</code>.
* <p>
* The character at index <i>k</i> in this sequence becomes equal to:
* <ul>
* <li>the character at index <i>k</i> in this sequence, if
* <i>k</i> is less than <code>dstOffset</code>
* <li>the character at index <i>k</i><code>+start-dstOffset</code> in
* the argument <code>s</code>, if <i>k</i> is greater than or equal to
* <code>dstOffset</code> but is less than <code>dstOffset+end-start</code>
* <li>the character at index <i>k</i><code>-(end-start)</code> in this
* sequence, if <i>k</i> is greater than or equal to
* <code>dstOffset+end-start</code>
* </ul><p>
* The dstOffset argument must be greater than or equal to
* <code>0</code>, and less than or equal to the length of this
* sequence.
* <p>The start argument must be nonnegative, and not greater than
* <code>end</code>.
* <p>The end argument must be greater than or equal to
* <code>start</code>, and less than or equal to the length of s.
*
* <p>If <code>s</code> is <code>null</code>, then this method inserts
* characters as if the s parameter was a sequence containing the four
* characters <code>"null"</code>.
*
* @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</code>
* is negative or greater than <code>this.length()</code>, or
* <code>start</code> or <code>end</code> are negative, or
* <code>start</code> is greater than <code>end</code> or
* <code>end</code> is greater than <code>s.length()</code>
*/
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;
if (len == 0)
return this;
int newCount = count + len;
if (newCount > value.length)
expandCapacity(newCount);
System.arraycopy(value, dstOffset, value, dstOffset + len,
count - dstOffset);
for (int i=start; i<end; i++)
value[dstOffset++] = s.charAt(i);
count = newCount;
return this;
}
/**
* Inserts the string representation of the <code>boolean</code>
* argument into this sequence.
* <p>
* The second argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then inserted into this sequence at the indicated
* offset.
* <p>
* The offset argument must be greater than or equal to
* <code>0</code>, and less than or equal to the length of this
* sequence.
*
* @param offset the offset.
* @param b a <code>boolean</code>.
* @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</code>
* argument into this sequence.
* <p>
* The second argument is inserted into the contents of this sequence
* at the position indicated by <code>offset</code>. The length
* of this sequence increases by one.
* <p>
* 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 #insert(int, String) inserted} into
* this character sequence at the position indicated by
* <code>offset</code>.
* <p>
* The offset argument must be greater than or equal to
* <code>0</code>, and less than or equal to the length of this
* sequence.
*
* @param offset the offset.
* @param c a <code>char</code>.
* @return a reference to this object.
* @throws IndexOutOfBoundsException if the offset is invalid.
*/
public AbstractStringBuilder insert(int offset, char c) {
int newCount = count + 1;
if (newCount > value.length)
expandCapacity(newCount);
System.arraycopy(value, offset, value, offset + 1, count - offset);
value[offset] = c;
count = newCount;
return this;
}
/**
* Inserts the string representation of the second <code>int</code>
* argument into this sequence.
* <p>
* The second argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then inserted into this sequence at the indicated
* offset.
* <p>
* The offset argument must be greater than or equal to
* <code>0</code>, and less than or equal to the length of this
* sequence.
*
* @param offset the offset.
* @param i an <code>int</code>.
* @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</code>
* argument into this sequence.
* <p>
* The second argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then inserted into this sequence at the position
* indicated by <code>offset</code>.
* <p>
* The offset argument must be greater than or equal to
* <code>0</code>, and less than or equal to the length of this
* sequence.
*
* @param offset the offset.
* @param l a <code>long</code>.
* @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</code>
* argument into this sequence.
* <p>
* The second argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then inserted into this sequence at the indicated
* offset.
* <p>
* The offset argument must be greater than or equal to
* <code>0</code>, and less than or equal to the length of this
* sequence.
*
* @param offset the offset.
* @param f a <code>float</code>.
* @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</code>
* argument into this sequence.
* <p>
* The second argument is converted to a string as if by the method
* <code>String.valueOf</code>, and the characters of that
* string are then inserted into this sequence at the indicated
* offset.
* <p>
* The offset argument must be greater than or equal to
* <code>0</code>, and less than or equal to the length of this
* sequence.
*
* @param offset the offset.
* @param d a <code>double</code>.
* @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
* <i>k</i> such that:
* <blockquote><pre>
* this.toString().startsWith(str, <i>k</i>)
* </pre></blockquote>
* is <code>true</code>.
*
* @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, <code>-1</code> is returned.
* @throws java.lang.NullPointerException if <code>str</code> is
* <code>null</code>.
*/
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 <tt>k</tt> for which:
* <blockquote><pre>
* k >= Math.min(fromIndex, str.length()) &&
* this.toString().startsWith(str, k)
* </pre></blockquote>
* If no such value of <i>k</i> 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 <code>str</code> is
* <code>null</code>.
*/
public int indexOf(String str, int fromIndex) {
return String.indexOf(value, 0, count,
str.toCharArray(), 0, str.length(), 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 <code>this.length()</code>.
* The returned index is the largest value <i>k</i> such that
* <blockquote><pre>
* this.toString().startsWith(str, k)
* </pre></blockquote>
* 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, <code>-1</code> is returned.
* @throws java.lang.NullPointerException if <code>str</code> is
* <code>null</code>.
*/
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 <i>k</i>
* such that:
* <blockquote><pre>
* k <= Math.min(fromIndex, str.length()) &&
* this.toString().startsWith(str, k)
* </pre></blockquote>
* If no such value of <i>k</i> 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 <code>str</code> is
* <code>null</code>.
*/
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 <i>n</i> be the character length of this character sequence
* (not the length in <code>char</code> values) just prior to
* execution of the <code>reverse</code> method. Then the
* character at index <i>k</i> in the new character sequence is
* equal to the character at index <i>n-k-1</i> in the old
* character sequence.
*
* <p>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 <code>String</code> object is allocated and initialized to
* contain the character sequence currently represented by this
* object. This <code>String</code> is then returned. Subsequent
* changes to this sequence do not affect the contents of the
* <code>String</code>.
*
* @return a string representation of this sequence of characters.
*/
public abstract String toString();
/**
* Needed by <tt>String</tt> for the contentEquals method.
*/
final char[] getValue() {
return value;
}
}
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