Java example source code file (AbstractStringBuilder.java)
The AbstractStringBuilder.java Java example source code/*
* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
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);
}
/**
* This method has the same contract as ensureCapacity, but is
* never synchronized.
*/
private void ensureCapacityInternal(int minimumCapacity) {
// overflow-conscious code
if (minimumCapacity - value.length > 0)
expandCapacity(minimumCapacity);
}
/**
* This implements the expansion semantics of ensureCapacity with no
* size check or synchronization.
*/
void expandCapacity(int minimumCapacity) {
int newCapacity = value.length * 2 + 2;
if (newCapacity - minimumCapacity < 0)
newCapacity = minimumCapacity;
if (newCapacity < 0) {
if (minimumCapacity < 0) // overflow
throw new OutOfMemoryError();
newCapacity = Integer.MAX_VALUE;
}
value = Arrays.copyOf(value, newCapacity);
}
/**
* Attempts to reduce storage used for the character sequence.
* If the buffer is larger than necessary to hold its current sequence of
* characters, then it may be resized to become more space efficient.
* Calling this method may, but is not required to, affect the value
* returned by a subsequent call to the {@link #capacity()} method.
*/
public void trimToSize() {
if (count < value.length) {
value = 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 less than {@code newLength}, the character at
* index <i>k in the new character sequence is the same as the
* character at index <i>k in the old sequence if k 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, 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 be the length of this character sequence just prior to
* execution of the {@code append} method. Then the character at
* index <i>k in the new character sequence is equal to the character
* at index <i>k in the old character sequence, if k is less
* than <i>n; otherwise, it is equal to the character at index
* <i>k-n in the argument {@code str}.
*
* @param str a string.
* @return a reference to this object.
*/
public AbstractStringBuilder append(String str) {
if (str == null)
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 be the length of this character sequence just prior to
* execution of the {@code append} method. Then the character at
* index <i>k in this character sequence becomes equal to the
* character at index <i>k in this sequence, if k is less than
* <i>n; otherwise, it is equal to the character at index
* <i>k+start-n 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 in the new character sequence is
* equal to:
* <ul>
* <li>the character at index k in the old character sequence, if
* <i>k is less than {@code offset}
* <li>the character at index k{@code -offset} in the
* argument {@code str}, if <i>k is not less than
* {@code offset} but is less than {@code offset+str.length()}
* <li>the character at index k{@code -str.length()} in the
* old character sequence, if <i>k is not less than
* {@code offset+str.length()}
* </ul>
Other Java examples (source code examples)Here is a short list of links related to this Java AbstractStringBuilder.java source code file: |
The search page
Other Java source code examples at this package level
Click here to learn more about this project
