/*
* Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
*
*
*
*
*
*
*
*
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*
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*
*
*
*/
package java.lang;
import sun.misc.
FloatingDecimal;
import java.util.
Arrays;
/**
* 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.
*
* <p>Unless otherwise noted, passing a {@code null} argument to a constructor
* or method in this class will cause a {@link NullPointerException} to be
* thrown.
*
* @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
*/
@
Override
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} argument.
* <li>Twice the old capacity, plus {@code 2}.
* </ul>
* If the {@code minimumCapacity} argument is nonpositive, this
* method takes no action and simply returns.
* Note that subsequent operations on this object can reduce the
* actual capacity below that requested here.
*
* @param minimumCapacity the minimum desired capacity.
*/
public void
ensureCapacity(int
minimumCapacity) {
if (
minimumCapacity > 0)
ensureCapacityInternal(
minimumCapacity);
}
/**
* For positive values of {@code minimumCapacity}, this method
* behaves like {@code ensureCapacity}, however it is never
* synchronized.
* If {@code minimumCapacity} is non positive due to numeric
* overflow, this method throws {@code OutOfMemoryError}.
*/
private void
ensureCapacityInternal(int
minimumCapacity) {
// overflow-conscious code
if (
minimumCapacity -
value.length > 0) {
value =
Arrays.
copyOf(
value,
newCapacity(
minimumCapacity));
}
}
/**
* The maximum size of array to allocate (unless necessary).
* Some VMs reserve some header words in an array.
* Attempts to allocate larger arrays may result in
* OutOfMemoryError: Requested array size exceeds VM limit
*/
private static final int
MAX_ARRAY_SIZE =
Integer.
MAX_VALUE - 8;
/**
* Returns a capacity at least as large as the given minimum capacity.
* Returns the current capacity increased by the same amount + 2 if
* that suffices.
* Will not return a capacity greater than {@code MAX_ARRAY_SIZE}
* unless the given minimum capacity is greater than that.
*
* @param minCapacity the desired minimum capacity
* @throws OutOfMemoryError if minCapacity is less than zero or
* greater than Integer.MAX_VALUE
*/
private int
newCapacity(int
minCapacity) {
// overflow-conscious code
int
newCapacity = (
value.length << 1) + 2;
if (
newCapacity -
minCapacity < 0) {
newCapacity =
minCapacity;
}
return (
newCapacity <= 0 ||
MAX_ARRAY_SIZE -
newCapacity < 0)
?
hugeCapacity(
minCapacity)
:
newCapacity;
}
private int
hugeCapacity(int
minCapacity) {
if (
Integer.
MAX_VALUE -
minCapacity < 0) { // overflow
throw new
OutOfMemoryError();
}
return (
minCapacity >
MAX_ARRAY_SIZE)
?
minCapacity :
MAX_ARRAY_SIZE;
}
/**
* 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 =
Arrays.
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 <i>k</i> less than {@code newLength}, 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 '\u005Cu0000'}.
*
* In other words, if the {@code newLength} argument is less than
* the current length, the length is changed to the specified length.
* <p>
* If the {@code newLength} argument is greater than or equal
* to the current length, sufficient null characters
* ({@code '\u005Cu0000'}) are appended so that
* length becomes the {@code newLength} argument.
* <p>
* The {@code newLength} argument must be greater than or equal
* to {@code 0}.
*
* @param newLength the new length
* @throws IndexOutOfBoundsException if the
* {@code newLength} argument is negative.
*/
public void
setLength(int
newLength) {
if (
newLength < 0)
throw new
StringIndexOutOfBoundsException(
newLength);
ensureCapacityInternal(
newLength);
if (
count <
newLength) {
Arrays.
fill(
value,
count,
newLength, '\0');
}
count =
newLength;
}
/**
* Returns the {@code char} value in this sequence at the specified index.
* The first {@code char} value is at index {@code 0}, the next at index
* {@code 1}, and so on, as in array indexing.
* <p>
* The index argument must be greater than or equal to
* {@code 0}, and less than the length of this sequence.
*
* <p>If the {@code char} 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} value.
* @return the {@code char} value at the specified index.
* @throws IndexOutOfBoundsException if {@code index} is
* negative or greater than or equal to {@code length()}.
*/
@
Override
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} values
* (Unicode code units) and ranges from {@code 0} to
* {@link #length()}{@code - 1}.
*
* <p> If the {@code 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
* {@code 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 {@code char} value at the given index is returned.
*
* @param index the index to the {@code char} values
* @return the code point value of the character at the
* {@code index}
* @exception IndexOutOfBoundsException if the {@code 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.
codePointAtImpl(
value,
index,
count);
}
/**
* Returns the character (Unicode code point) before the specified
* index. The index refers to {@code char} values
* (Unicode code units) and ranges from {@code 1} to {@link
* #length()}.
*
* <p> If the {@code char} value at {@code (index - 1)}
* is in the low-surrogate range, {@code (index - 2)} is not
* negative, and the {@code char} value at {@code (index -
* 2)} is in the high-surrogate range, then the
* supplementary code point value of the surrogate pair is
* returned. If the {@code char} value at {@code 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 {@code 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.
codePointBeforeImpl(
value,
index, 0);
}
/**
* Returns the number of Unicode code points in the specified text
* range of this sequence. The text range begins at the specified
* {@code beginIndex} and extends to the {@code char} at
* index {@code endIndex - 1}. Thus the length (in
* {@code char}s) of the text range is
* {@code endIndex-beginIndex}. Unpaired surrogates within
* this sequence count as one code point each.
*
* @param beginIndex the index to the first {@code char} of
* the text range.
* @param endIndex the index after the last {@code char} of
* the text range.
* @return the number of Unicode code points in the specified text
* range
* @exception IndexOutOfBoundsException if the
* {@code beginIndex} is negative, or {@code endIndex}
* is larger than the length of this sequence, or
* {@code beginIndex} is larger than {@code 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 {@code index} by {@code codePointOffset} code
* points. Unpaired surrogates within the text range given by
* {@code index} and {@code 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 {@code index}
* is negative or larger then the length of this sequence,
* or if {@code codePointOffset} is positive and the subsequence
* starting with {@code index} has fewer than
* {@code codePointOffset} code points,
* or if {@code codePointOffset} is negative and the subsequence
* before {@code index} has fewer than the absolute value of
* {@code 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 {@code dst}. The first character to
* be copied is at index {@code srcBegin}; the last character to
* be copied is at index {@code srcEnd-1}. The total number of
* characters to be copied is {@code srcEnd-srcBegin}. The
* characters are copied into the subarray of {@code dst} starting
* at index {@code dstBegin} and ending at index:
* <pre>{@code
* dstbegin + (srcEnd-srcBegin) - 1
* }</pre>
*
* @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}.
* @throws IndexOutOfBoundsException if any of the following is true:
* <ul>
* <li>{@code srcBegin} is negative
* <li>{@code dstBegin} is negative
* <li>the {@code srcBegin} argument is greater than
* the {@code srcEnd} argument.
* <li>{@code srcEnd} is greater than
* {@code this.length()}.
* <li>{@code dstBegin+srcEnd-srcBegin} is greater than
* {@code dst.length}
* </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}. 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} at position {@code index}.
* <p>
* The index argument must be greater than or equal to
* {@code 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 {@code index} is
* negative or greater than or equal to {@code 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.
* <p>
* 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.
* <p>
* 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.
* <p>
* Let <i>n</i> be the length of this character sequence just prior to
* execution of the {@code append} 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}.
*
* @param str a string.
* @return a reference to this object.
*/
public
AbstractStringBuilder append(
String str) {
if (
str == null)
return
appendNull();
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
appendNull();
int
len =
sb.
length();
ensureCapacityInternal(
count +
len);
sb.
getChars(0,
len,
value,
count);
count +=
len;
return this;
}
/**
* @since 1.8
*/
AbstractStringBuilder append(
AbstractStringBuilder asb) {
if (
asb == null)
return
appendNull();
int
len =
asb.
length();
ensureCapacityInternal(
count +
len);
asb.
getChars(0,
len,
value,
count);
count +=
len;
return this;
}
// Documentation in subclasses because of synchro difference
@
Override
public
AbstractStringBuilder append(
CharSequence s) {
if (
s == null)
return
appendNull();
if (
s instanceof
String)
return this.
append((
String)
s);
if (
s instanceof
AbstractStringBuilder)
return this.
append((
AbstractStringBuilder)
s);
return this.
append(
s, 0,
s.
length());
}
private
AbstractStringBuilder appendNull() {
int
c =
count;
ensureCapacityInternal(
c + 4);
final char[]
value = this.
value;
value[
c++] = 'n';
value[
c++] = 'u';
value[
c++] = 'l';
value[
c++] = 'l';
count =
c;
return this;
}
/**
* Appends a subsequence of the specified {@code CharSequence} to this
* sequence.
* <p>
* 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}.
* <p>
* Let <i>n</i> be the length of this character sequence just prior to
* execution of the {@code append} 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}.
* <p>
* 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()}
*/
@
Override
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.
* <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
len =
str.length;
ensureCapacityInternal(
count +
len);
System.
arraycopy(
str, 0,
value,
count,
len);
count +=
len;
return this;
}
/**
* Appends the string representation of a subarray of the
* {@code char} array argument to this sequence.
* <p>
* 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}.
* <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} to append.
* @param len the number of {@code char}s to append.
* @return a reference to this object.
* @throws IndexOutOfBoundsException
* if {@code offset < 0} or {@code len < 0}
* or {@code offset+len > str.length}
*/
public
AbstractStringBuilder append(char
str[], int
offset, int
len) {
if (
len > 0) // let arraycopy report AIOOBE for len < 0
ensureCapacityInternal(
count +
len);
System.
arraycopy(
str,
offset,
value,
count,
len);
count +=
len;
return this;
}
/**
* Appends the string representation of the {@code boolean}
* argument to the sequence.
* <p>
* 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.
* <p>
* The argument is appended to the contents of this sequence.
* The length of this sequence increases by {@code 1}.
* <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}.
* @return a reference to this object.
*/
@
Override
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.
* <p>
* 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) {
if (
i ==
Integer.
MIN_VALUE) {
append("-2147483648");
return this;
}
int
appendedLength = (
i < 0) ?
Integer.
stringSize(-
i) + 1
:
Integer.
stringSize(
i);
int
spaceNeeded =
count +
appendedLength;
ensureCapacityInternal(
spaceNeeded);
Integer.
getChars(
i,
spaceNeeded,
value);
count =
spaceNeeded;
return this;
}
/**
* Appends the string representation of the {@code long}
* argument to this sequence.
* <p>
* 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.
* <p>
* 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) {
FloatingDecimal.
appendTo(
f,this);
return this;
}
/**
* Appends the string representation of the {@code double}
* argument to this sequence.
* <p>
* 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) {
FloatingDecimal.
appendTo(
d,this);
return this;
}
/**
* Removes the characters in a substring of this sequence.
* The substring begins at the specified {@code start} and extends to
* the character at index {@code end - 1} or to the end of the
* sequence if no such character exists. If
* {@code start} is equal to {@code end}, no changes are made.
*
* @param start The beginning index, inclusive.
* @param end The ending index, exclusive.
* @return This object.
* @throws StringIndexOutOfBoundsException if {@code start}
* is negative, greater than {@code length()}, or
* greater than {@code end}.
*/
public
AbstractStringBuilder delete(int
start, int
end) {
if (
start < 0)
throw new
StringIndexOutOfBoundsException(
start);
if (
end >
count)
end =
count;
if (
start >
end)
throw new
StringIndexOutOfBoundsException();
int
len =
end -
start;
if (
len > 0) {
System.
arraycopy(
value,
start+
len,
value,
start,
count-
end);
count -=
len;
}
return this;
}
/**
* Appends the string representation of the {@code codePoint}
* argument to this sequence.
*
* <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} 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 {@code char} at the specified position in this
* sequence. This sequence is shortened by one {@code char}.
*
* <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}s to remove by calling
* {@code Character.charCount(thisSequence.codePointAt(index))},
* where {@code thisSequence} is this sequence.
*
* @param index Index of {@code char} to remove
* @return This object.
* @throws StringIndexOutOfBoundsException if the {@code index}
* is negative or greater than or equal to
* {@code length()}.
*/
public
AbstractStringBuilder deleteCharAt(int
index) {
if ((
index < 0) || (
index >=
count))
throw new
StringIndexOutOfBoundsException(
index);
System.
arraycopy(
value,
index+1,
value,
index,
count-
index-1);
count--;
return this;
}
/**
* Replaces the characters in a substring of this sequence
* with characters in the specified {@code String}. 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. First the
* characters in the substring are removed and then the specified
* {@code String} is inserted at {@code 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 {@code start}
* is negative, greater than {@code length()}, or
* greater than {@code end}.
*/
public
AbstractStringBuilder replace(int
start, int
end,
String str) {
if (
start < 0)
throw new
StringIndexOutOfBoundsException(
start);
if (
start >
count)
throw new
StringIndexOutOfBoundsException("start > length()");
if (
start >
end)
throw new
StringIndexOutOfBoundsException("start > end");
if (
end >
count)
end =
count;
int
len =
str.
length();
int
newCount =
count +
len - (
end -
start);
ensureCapacityInternal(
newCount);
System.
arraycopy(
value,
end,
value,
start +
len,
count -
end);
str.
getChars(
value,
start);
count =
newCount;
return this;
}
/**
* Returns a new {@code 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 {@code 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.
*
* <p> An invocation of this method of the form
*
* <pre>{@code
* sb.subSequence(begin, end)}</pre>
*
* behaves in exactly the same way as the invocation
*
* <pre>{@code
* sb.substring(begin, end)}</pre>
*
* 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 {@code start} or {@code end} are negative,
* if {@code end} is greater than {@code length()},
* or if {@code start} is greater than {@code end}
* @spec JSR-51
*/
@
Override
public
CharSequence subSequence(int
start, int
end) {
return
substring(
start,
end);
}
/**
* Returns a new {@code String} that contains a subsequence of
* characters currently contained in this sequence. The
* substring begins at the specified {@code start} and
* extends to the character at index {@code end - 1}.
*
* @param start The beginning index, inclusive.
* @param end The ending index, exclusive.
* @return The new string.
* @throws StringIndexOutOfBoundsException if {@code start}
* or {@code end} are negative or greater than
* {@code length()}, or {@code start} is
* greater than {@code end}.
*/
public
String substring(int
start, int
end) {
if (
start < 0)
throw new
StringIndexOutOfBoundsException(
start);
if (
end >
count)
throw new
StringIndexOutOfBoundsException(
end);
if (
start >
end)
throw new
StringIndexOutOfBoundsException(
end -
start);
return new
String(
value,
start,
end -
start);
}
/**
* Inserts the string representation of a subarray of the {@code str}
* array argument into this sequence. The subarray begins at the
* specified {@code offset} and extends {@code len} {@code char}s.
* The characters of the subarray are inserted into this sequence at
* the position indicated by {@code index}. The length of this
* sequence increases by {@code len} {@code char}s.
*
* @param index position at which to insert subarray.
* @param str A {@code char} array.
* @param offset the index of the first {@code char} in subarray to
* be inserted.
* @param len the number of {@code char}s in the subarray to
* be inserted.
* @return This object
* @throws StringIndexOutOfBoundsException if {@code index}
* is negative or greater than {@code length()}, or
* {@code offset} or {@code len} are negative, or
* {@code (offset+len)} is greater than
* {@code str.length}.
*/
public
AbstractStringBuilder insert(int
index, char[]
str, int
offset,
int
len)
{
if ((
index < 0) || (
index >
length()))
throw new
StringIndexOutOfBoundsException(
index);
if ((
offset < 0) || (
len < 0) || (
offset >
str.length -
len))
throw new
StringIndexOutOfBoundsException(
"offset " +
offset + ", len " +
len + ", str.length "
+
str.length);
ensureCapacityInternal(
count +
len);
System.
arraycopy(
value,
index,
value,
index +
len,
count -
index);
System.
arraycopy(
str,
offset,
value,
index,
len);
count +=
len;
return this;
}
/**
* Inserts the string representation of the {@code Object}
* argument into this character sequence.
* <p>
* 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.
* <p>
* 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.
* <p>
* 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.
* <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}
* <li>the character at index <i>k</i>{@code -offset} in the
* argument {@code str}, if <i>k</i> is not less than
* {@code offset} but is less than {@code offset+str.length()}
* <li>the character at index <i>k</i>{@code -str.length()} in the
* old character sequence, if <i>k</i> is not less than
* {@code offset+str.length()}
* </ul><p>
* The {@code offset} argument must be greater than or equal to
* {@code 0}, and less than or equal to the {@linkplain #length() length}
* of this sequence.
*
* @param offset the offset.
* @param str a string.
* @return a reference to this object.
* @throws StringIndexOutOfBoundsException if the offset is invalid.
*/
public
AbstractStringBuilder insert(int
offset,
String str) {
if ((
offset < 0) || (
offset >
length()))
throw new
StringIndexOutOfBoundsException(
offset);
if (
str == null)
str = "null";
int
len =
str.
length();
ensureCapacityInternal(
count +
len);
System.
arraycopy(
value,
offset,
value,
offset +
len,
count -
offset);
str.
getChars(
value,
offset);
count +=
len;
return this;
}
/**
* Inserts the string representation of the {@code char} array
* argument into this sequence.
* <p>
* 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.
* <p>
* 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.
* <p>
* The {@code offset} argument must be greater than or equal to
* {@code 0}, and less than or equal to the {@linkplain #length() length}
* of this sequence.
*
* @param offset the offset.
* @param str a character array.
* @return a reference to this object.
* @throws StringIndexOutOfBoundsException if the offset is invalid.
*/
public
AbstractStringBuilder insert(int
offset, char[]
str) {
if ((
offset < 0) || (
offset >
length()))
throw new
StringIndexOutOfBoundsException(
offset);
int
len =
str.length;
ensureCapacityInternal(
count +
len);
System.
arraycopy(
value,
offset,
value,
offset +
len,
count -
offset);
System.
arraycopy(
str, 0,
value,
offset,
len);
count +=
len;
return this;
}
/**
* Inserts the specified {@code CharSequence} into this sequence.
* <p>
* 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.
* <p>
* 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.
*
* <p>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.
* <p>
* 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}.
* <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}
* <li>the character at index <i>k</i>{@code +start-dstOffset} in
* the argument {@code s}, if <i>k</i> is greater than or equal to
* {@code dstOffset} but is less than {@code dstOffset+end-start}
* <li>the character at index <i>k</i>{@code -(end-start)} in this
* sequence, if <i>k</i> is greater than or equal to
* {@code dstOffset+end-start}
* </ul><p>
* 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.
* <p>The start argument must be nonnegative, and not greater than
* {@code end}.
* <p>The end argument must be greater than or equal to
* {@code start}, and less than or equal to the length of s.
*
* <p>If {@code s} is {@code null}, then this method inserts
* characters as if the s parameter was a sequence containing the four
* characters {@code "null"}.
*
* @param dstOffset the offset in this sequence.
* @param s the sequence to be inserted.
* @param start the starting index of the subsequence to be inserted.
* @param end the end index of the subsequence to be inserted.
* @return a reference to this object.
* @throws IndexOutOfBoundsException if {@code dstOffset}
* is negative or greater than {@code this.length()}, or
* {@code start} or {@code end} are negative, or
* {@code start} is greater than {@code end} or
* {@code end} is greater than {@code s.length()}
*/
public
AbstractStringBuilder insert(int
dstOffset,
CharSequence s,
int
start, int
end) {
if (
s == null)
s = "null";
if ((
dstOffset < 0) || (
dstOffset > this.
length()))
throw new
IndexOutOfBoundsException("dstOffset "+
dstOffset);
if ((
start < 0) || (
end < 0) || (
start >
end) || (
end >
s.
length()))
throw new
IndexOutOfBoundsException(
"start " +
start + ", end " +
end + ", s.length() "
+
s.
length());
int
len =
end -
start;
ensureCapacityInternal(
count +
len);
System.
arraycopy(
value,
dstOffset,
value,
dstOffset +
len,
count -
dstOffset);
for (int
i=
start;
i<
end;
i++)
value[
dstOffset++] =
s.
charAt(
i);
count +=
len;
return this;
}
/**
* Inserts the string representation of the {@code boolean}
* argument into this sequence.
* <p>
* The overall effect is exactly as if the second argument were
* converted to a string by the method {@link String#valueOf(boolean)},
* and the characters of that string were then
* {@link #insert(int,String) inserted} into this character
* sequence at the indicated offset.
* <p>
* 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.
* <p>
* 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.
* <p>
* The {@code offset} argument must be greater than or equal to
* {@code 0}, and less than or equal to the {@linkplain #length() length}
* of this sequence.
*
* @param offset the offset.
* @param c a {@code char}.
* @return a reference to this object.
* @throws IndexOutOfBoundsException if the offset is invalid.
*/
public
AbstractStringBuilder insert(int
offset, char
c) {
ensureCapacityInternal(
count + 1);
System.
arraycopy(
value,
offset,
value,
offset + 1,
count -
offset);
value[
offset] =
c;
count += 1;
return this;
}
/**
* Inserts the string representation of the second {@code int}
* argument into this sequence.
* <p>
* 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.
* <p>
* 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.
* <p>
* 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.
* <p>
* 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.
* <p>
* 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.
* <p>
* 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.
* <p>
* 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.
* <p>
* 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
* <i>k</i> such that:
* <pre>{@code
* this.toString().startsWith(str, <i>k</i>)
* }</pre>
* is {@code 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, {@code -1} is returned.
*/
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 {@code k} for which:
* <pre>{@code
* k >= Math.min(fromIndex, this.length()) &&
* this.toString().startsWith(str, k)
* }</pre>
* 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.
*/
public int
indexOf(
String str, int
fromIndex) {
return
String.
indexOf(
value, 0,
count,
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 {@code this.length()}.
* The returned index is the largest value <i>k</i> such that
* <pre>{@code
* this.toString().startsWith(str, k)
* }</pre>
* 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} is returned.
*/
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:
* <pre>{@code
* k <= Math.min(fromIndex, this.length()) &&
* this.toString().startsWith(str, k)
* }</pre>
* 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.
*/
public int
lastIndexOf(
String str, int
fromIndex) {
return
String.
lastIndexOf(
value, 0,
count,
str,
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} values) just prior to
* execution of the {@code reverse} 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
* "\u005CuDC00\u005CuD800" produces "\u005CuD800\u005CuDC00" which is
* a valid surrogate pair.
*
* @return a reference to this object.
*/
public
AbstractStringBuilder reverse() {
boolean
hasSurrogates = false;
int
n =
count - 1;
for (int
j = (
n-1) >> 1;
j >= 0;
j--) {
int
k =
n -
j;
char
cj =
value[
j];
char
ck =
value[
k];
value[
j] =
ck;
value[
k] =
cj;
if (
Character.
isSurrogate(
cj) ||
Character.
isSurrogate(
ck)) {
hasSurrogates = true;
}
}
if (
hasSurrogates) {
reverseAllValidSurrogatePairs();
}
return this;
}
/** Outlined helper method for reverse() */
private void
reverseAllValidSurrogatePairs() {
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;
}
}
}
}
/**
* Returns a string representing the data in this sequence.
* A new {@code String} object is allocated and initialized to
* contain the character sequence currently represented by this
* object. This {@code String} is then returned. Subsequent
* changes to this sequence do not affect the contents of the
* {@code String}.
*
* @return a string representation of this sequence of characters.
*/
@
Override
public abstract
String toString();
/**
* Needed by {@code String} for the contentEquals method.
*/
final char[]
getValue() {
return
value;
}
}