* 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. * *
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: *
* 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. *
* 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. *
* The index argument must be greater than or equal to * {@code 0}, and less than the length of this sequence. * *
If the {@code char} value specified by the index is a * 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}. * *
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()}. * *
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: *
{@code
* dstbegin + (srcEnd-srcBegin) - 1
* }
*
* @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:
* * 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. *
* The overall effect is exactly as if the argument were converted * to a string by the method {@link String#valueOf(Object)}, * and the characters of that string were then * {@link #append(String) appended} to this character sequence. * * @param obj an {@code Object}. * @return a reference to this object. */ public AbstractStringBuilder append(Object obj) { return append(String.valueOf(obj)); } /** * Appends the specified string to this character sequence. *
* The characters of the {@code String} argument are appended, in * order, increasing the length of this sequence by the length of the * argument. If {@code str} is {@code null}, then the four * characters {@code "null"} are appended. *
* Let n be the length of this character sequence just prior to * execution of the {@code append} method. Then the character at * index k in the new character sequence is equal to the character * at index k in the old character sequence, if k is less * than n; otherwise, it is equal to the character at index * k-n in the argument {@code str}. * * @param str a string. * @return a reference to this object. */ public AbstractStringBuilder append(String str) { if (str == null) 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. *
* Characters of the argument {@code s}, starting at * index {@code start}, are appended, in order, to the contents of * this sequence up to the (exclusive) index {@code end}. The length * of this sequence is increased by the value of {@code end - start}. *
* Let n be the length of this character sequence just prior to * execution of the {@code append} method. Then the character at * index k in this character sequence becomes equal to the * character at index k in this sequence, if k is less than * n; otherwise, it is equal to the character at index * k+start-n in the argument {@code s}. *
* If {@code s} is {@code null}, then this method appends * characters as if the s parameter was a sequence containing the four * characters {@code "null"}. * * @param s the sequence to append. * @param start the starting index of the subsequence to be appended. * @param end the end index of the subsequence to be appended. * @return a reference to this object. * @throws IndexOutOfBoundsException if * {@code start} is negative, or * {@code start} is greater than {@code end} or * {@code end} is greater than {@code s.length()} */ @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 StringIndexOutOfBoundsException( "start " + start + ", end " + end + ", s.length() " + s.length()); int len = end - start; ensureCapacityInternal(count + len); if (s instanceof String) { ((String)s).getChars(start, end, value, count); } else { for (int i = start, j = count; i < end; i++, j++) value[j] = s.charAt(i); } count += len; return this; } /** * Appends the string representation of the {@code char} array * argument to this sequence. *
* The characters of the array argument are appended, in order, to * the contents of this sequence. The length of this sequence * increases by the length of the argument. *
* The overall effect is exactly as if the argument were converted * to a string by the method {@link String#valueOf(char[])}, * and the characters of that string were then * {@link #append(String) appended} to this character sequence. * * @param str the characters to be appended. * @return a reference to this object. */ public AbstractStringBuilder append(char[] str) { int len = str.length; ensureCapacityInternal(count + len); System.arraycopy(str, 0, value, count, len); count += len; return this; } /** * Appends the string representation of a subarray of the * {@code char} array argument to this sequence. *
* Characters of the {@code char} array {@code str}, starting at * index {@code offset}, are appended, in order, to the contents * of this sequence. The length of this sequence increases * by the value of {@code len}. *
* The overall effect is exactly as if the arguments were converted * to a string by the method {@link String#valueOf(char[],int,int)}, * and the characters of that string were then * {@link #append(String) appended} to this character sequence. * * @param str the characters to be appended. * @param offset the index of the first {@code char} to append. * @param len the number of {@code char}s to append. * @return a reference to this object. * @throws IndexOutOfBoundsException * if {@code offset < 0} or {@code len < 0} * or {@code offset+len > str.length} */ public AbstractStringBuilder append(char str[], int offset, int len) { if (len > 0) // let arraycopy report AIOOBE for len < 0 ensureCapacityInternal(count + len); System.arraycopy(str, offset, value, count, len); count += len; return this; } /** * Appends the string representation of the {@code boolean} * argument to the sequence. *
* The overall effect is exactly as if the argument were converted * to a string by the method {@link String#valueOf(boolean)}, * and the characters of that string were then * {@link #append(String) appended} to this character sequence. * * @param b a {@code boolean}. * @return a reference to this object. */ public AbstractStringBuilder append(boolean b) { if (b) { ensureCapacityInternal(count + 4); value[count++] = 't'; value[count++] = 'r'; value[count++] = 'u'; value[count++] = 'e'; } else { ensureCapacityInternal(count + 5); value[count++] = 'f'; value[count++] = 'a'; value[count++] = 'l'; value[count++] = 's'; value[count++] = 'e'; } return this; } /** * Appends the string representation of the {@code char} * argument to this sequence. *
* The argument is appended to the contents of this sequence. * The length of this sequence increases by {@code 1}. *
* The overall effect is exactly as if the argument were converted * to a string by the method {@link String#valueOf(char)}, * and the character in that string were then * {@link #append(String) appended} to this character sequence. * * @param c a {@code char}. * @return a reference to this object. */ @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. *
* 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. *
* The overall effect is exactly as if the argument were converted * to a string by the method {@link String#valueOf(long)}, * and the characters of that string were then * {@link #append(String) appended} to this character sequence. * * @param l a {@code long}. * @return a reference to this object. */ public AbstractStringBuilder append(long l) { if (l == Long.MIN_VALUE) { append("-9223372036854775808"); return this; } int appendedLength = (l < 0) ? Long.stringSize(-l) + 1 : Long.stringSize(l); int spaceNeeded = count + appendedLength; ensureCapacityInternal(spaceNeeded); Long.getChars(l, spaceNeeded, value); count = spaceNeeded; return this; } /** * Appends the string representation of the {@code float} * argument to this sequence. *
* The overall effect is exactly as if the argument were converted * to a string by the method {@link String#valueOf(float)}, * and the characters of that string were then * {@link #append(String) appended} to this character sequence. * * @param f a {@code float}. * @return a reference to this object. */ public AbstractStringBuilder append(float f) { FloatingDecimal.appendTo(f,this); return this; } /** * Appends the string representation of the {@code double} * argument to this sequence. *
* The overall effect is exactly as if the argument were converted * to a string by the method {@link String#valueOf(double)}, * and the characters of that string were then * {@link #append(String) appended} to this character sequence. * * @param d a {@code double}. * @return a reference to this object. */ public AbstractStringBuilder append(double d) { 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. * *
The argument is appended to the contents of this sequence. * The length of this sequence increases by * {@link Character#charCount(int) Character.charCount(codePoint)}. * *
The overall effect is exactly as if the argument were * converted to a {@code char} array by the method * {@link Character#toChars(int)} and the character in that array * were then {@link #append(char[]) appended} to this character * sequence. * * @param codePoint a Unicode code point * @return a reference to this object. * @exception IllegalArgumentException if the specified * {@code codePoint} isn't a valid Unicode code point */ public AbstractStringBuilder appendCodePoint(int codePoint) { final int count = this.count; if (Character.isBmpCodePoint(codePoint)) { ensureCapacityInternal(count + 1); value[count] = (char) codePoint; this.count = count + 1; } else if (Character.isValidCodePoint(codePoint)) { ensureCapacityInternal(count + 2); Character.toSurrogates(codePoint, value, count); this.count = count + 2; } else { throw new IllegalArgumentException(); } return this; } /** * Removes the {@code char} at the specified position in this * sequence. This sequence is shortened by one {@code char}. * *
Note: If the character at the given index is a supplementary * character, this method does not remove the entire character. If * correct handling of supplementary characters is required, * determine the number of {@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. * *
An invocation of this method of the form * *
{@code
* sb.subSequence(begin, end)}
*
* behaves in exactly the same way as the invocation
*
* {@code
* sb.substring(begin, end)}
*
* This method is provided so that this class can
* implement the {@link CharSequence} interface.
*
* @param start the start index, inclusive.
* @param end the end index, exclusive.
* @return the specified subsequence.
*
* @throws IndexOutOfBoundsException
* if {@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.
* * The overall effect is exactly as if the second argument were * converted to a string by the method {@link String#valueOf(Object)}, * and the characters of that string were then * {@link #insert(int,String) inserted} into this character * sequence at the indicated offset. *
* The {@code offset} argument must be greater than or equal to * {@code 0}, and less than or equal to the {@linkplain #length() length} * of this sequence. * * @param offset the offset. * @param obj an {@code Object}. * @return a reference to this object. * @throws StringIndexOutOfBoundsException if the offset is invalid. */ public AbstractStringBuilder insert(int offset, Object obj) { return insert(offset, String.valueOf(obj)); } /** * Inserts the string into this character sequence. *
* The characters of the {@code String} argument are inserted, in * order, into this sequence at the indicated offset, moving up any * characters originally above that position and increasing the length * of this sequence by the length of the argument. If * {@code str} is {@code null}, then the four characters * {@code "null"} are inserted into this sequence. *
* The character at index k in the new character sequence is * equal to: *
* The {@code offset} argument must be greater than or equal to * {@code 0}, and less than or equal to the {@linkplain #length() length} * of this sequence. * * @param offset the offset. * @param str a string. * @return a reference to this object. * @throws StringIndexOutOfBoundsException if the offset is invalid. */ public AbstractStringBuilder insert(int offset, String str) { if ((offset < 0) || (offset > length())) throw new StringIndexOutOfBoundsException(offset); if (str == null) str = "null"; int len = str.length(); ensureCapacityInternal(count + len); System.arraycopy(value, offset, value, offset + len, count - offset); str.getChars(value, offset); count += len; return this; } /** * Inserts the string representation of the {@code char} array * argument into this sequence. *
* The characters of the array argument are inserted into the * contents of this sequence at the position indicated by * {@code offset}. The length of this sequence increases by * the length of the argument. *
* The overall effect is exactly as if the second argument were * converted to a string by the method {@link String#valueOf(char[])}, * and the characters of that string were then * {@link #insert(int,String) inserted} into this character * sequence at the indicated offset. *
* The {@code offset} argument must be greater than or equal to * {@code 0}, and less than or equal to the {@linkplain #length() length} * of this sequence. * * @param offset the offset. * @param str a character array. * @return a reference to this object. * @throws StringIndexOutOfBoundsException if the offset is invalid. */ public AbstractStringBuilder insert(int offset, char[] str) { if ((offset < 0) || (offset > length())) throw new StringIndexOutOfBoundsException(offset); int len = str.length; ensureCapacityInternal(count + len); System.arraycopy(value, offset, value, offset + len, count - offset); System.arraycopy(str, 0, value, offset, len); count += len; return this; } /** * Inserts the specified {@code CharSequence} into this sequence. *
* The characters of the {@code CharSequence} argument are inserted, * in order, into this sequence at the indicated offset, moving up * any characters originally above that position and increasing the length * of this sequence by the length of the argument s. *
* The result of this method is exactly the same as if it were an * invocation of this object's * {@link #insert(int,CharSequence,int,int) insert}(dstOffset, s, 0, s.length()) * method. * *
If {@code s} is {@code null}, then the four characters * {@code "null"} are inserted into this sequence. * * @param dstOffset the offset. * @param s the sequence to be inserted * @return a reference to this object. * @throws IndexOutOfBoundsException if the offset is invalid. */ public AbstractStringBuilder insert(int dstOffset, CharSequence s) { if (s == null) s = "null"; if (s instanceof String) return this.insert(dstOffset, (String)s); return this.insert(dstOffset, s, 0, s.length()); } /** * Inserts a subsequence of the specified {@code CharSequence} into * this sequence. *
* The subsequence of the argument {@code s} specified by * {@code start} and {@code end} are inserted, * in order, into this sequence at the specified destination offset, moving * up any characters originally above that position. The length of this * sequence is increased by {@code end - start}. *
* The character at index k in this sequence becomes equal to: *
* The {@code dstOffset} argument must be greater than or equal to * {@code 0}, and less than or equal to the {@linkplain #length() length} * of this sequence. *
The start argument must be nonnegative, and not greater than * {@code end}. *
The end argument must be greater than or equal to * {@code start}, and less than or equal to the length of s. * *
If {@code s} is {@code null}, then this method inserts
* characters as if the s parameter was a sequence containing the four
* characters {@code "null"}.
*
* @param dstOffset the offset in this sequence.
* @param s the sequence to be inserted.
* @param start the starting index of the subsequence to be inserted.
* @param end the end index of the subsequence to be inserted.
* @return a reference to this object.
* @throws IndexOutOfBoundsException if {@code dstOffset}
* is negative or greater than {@code this.length()}, or
* {@code start} or {@code end} are negative, or
* {@code start} is greater than {@code end} or
* {@code end} is greater than {@code s.length()}
*/
public AbstractStringBuilder insert(int dstOffset, CharSequence s,
int start, int end) {
if (s == null)
s = "null";
if ((dstOffset < 0) || (dstOffset > this.length()))
throw new IndexOutOfBoundsException("dstOffset "+dstOffset);
if ((start < 0) || (end < 0) || (start > end) || (end > s.length()))
throw new IndexOutOfBoundsException(
"start " + start + ", end " + end + ", s.length() "
+ s.length());
int len = end - start;
ensureCapacityInternal(count + len);
System.arraycopy(value, dstOffset, value, dstOffset + len,
count - dstOffset);
for (int i=start; i
* The {@code offset} argument must be greater than or equal to
* {@code 0}, and less than or equal to the {@linkplain #length() length}
* of this sequence.
*
* @param offset the offset.
* @param b a {@code boolean}.
* @return a reference to this object.
* @throws StringIndexOutOfBoundsException if the offset is invalid.
*/
public AbstractStringBuilder insert(int offset, boolean b) {
return insert(offset, String.valueOf(b));
}
/**
* Inserts the string representation of the {@code char}
* argument into this sequence.
*
* The overall effect is exactly as if the second argument were
* converted to a string by the method {@link String#valueOf(char)},
* and the character in that string were then
* {@link #insert(int,String) inserted} into this character
* sequence at the indicated offset.
*
* The {@code offset} argument must be greater than or equal to
* {@code 0}, and less than or equal to the {@linkplain #length() length}
* of this sequence.
*
* @param offset the offset.
* @param c a {@code char}.
* @return a reference to this object.
* @throws IndexOutOfBoundsException if the offset is invalid.
*/
public AbstractStringBuilder insert(int offset, char c) {
ensureCapacityInternal(count + 1);
System.arraycopy(value, offset, value, offset + 1, count - offset);
value[offset] = c;
count += 1;
return this;
}
/**
* Inserts the string representation of the second {@code int}
* argument into this sequence.
*
* The overall effect is exactly as if the second argument were
* converted to a string by the method {@link String#valueOf(int)},
* and the characters of that string were then
* {@link #insert(int,String) inserted} into this character
* sequence at the indicated offset.
*
* The {@code offset} argument must be greater than or equal to
* {@code 0}, and less than or equal to the {@linkplain #length() length}
* of this sequence.
*
* @param offset the offset.
* @param i an {@code int}.
* @return a reference to this object.
* @throws StringIndexOutOfBoundsException if the offset is invalid.
*/
public AbstractStringBuilder insert(int offset, int i) {
return insert(offset, String.valueOf(i));
}
/**
* Inserts the string representation of the {@code long}
* argument into this sequence.
*
* The overall effect is exactly as if the second argument were
* converted to a string by the method {@link String#valueOf(long)},
* and the characters of that string were then
* {@link #insert(int,String) inserted} into this character
* sequence at the indicated offset.
*
* The {@code offset} argument must be greater than or equal to
* {@code 0}, and less than or equal to the {@linkplain #length() length}
* of this sequence.
*
* @param offset the offset.
* @param l a {@code long}.
* @return a reference to this object.
* @throws StringIndexOutOfBoundsException if the offset is invalid.
*/
public AbstractStringBuilder insert(int offset, long l) {
return insert(offset, String.valueOf(l));
}
/**
* Inserts the string representation of the {@code float}
* argument into this sequence.
*
* The overall effect is exactly as if the second argument were
* converted to a string by the method {@link String#valueOf(float)},
* and the characters of that string were then
* {@link #insert(int,String) inserted} into this character
* sequence at the indicated offset.
*
* The {@code offset} argument must be greater than or equal to
* {@code 0}, and less than or equal to the {@linkplain #length() length}
* of this sequence.
*
* @param offset the offset.
* @param f a {@code float}.
* @return a reference to this object.
* @throws StringIndexOutOfBoundsException if the offset is invalid.
*/
public AbstractStringBuilder insert(int offset, float f) {
return insert(offset, String.valueOf(f));
}
/**
* Inserts the string representation of the {@code double}
* argument into this sequence.
*
* The overall effect is exactly as if the second argument were
* converted to a string by the method {@link String#valueOf(double)},
* and the characters of that string were then
* {@link #insert(int,String) inserted} into this character
* sequence at the indicated offset.
*
* The {@code offset} argument must be greater than or equal to
* {@code 0}, and less than or equal to the {@linkplain #length() length}
* of this sequence.
*
* @param offset the offset.
* @param d a {@code double}.
* @return a reference to this object.
* @throws StringIndexOutOfBoundsException if the offset is invalid.
*/
public AbstractStringBuilder insert(int offset, double d) {
return insert(offset, String.valueOf(d));
}
/**
* Returns the index within this string of the first occurrence of the
* specified substring.
*
* The returned index is the smallest value {@code k} for which:
* The returned index is the smallest value {@code k} for which:
* The returned index is the largest value {@code k} for which:
* The returned index is the largest value {@code k} for which:
* 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();
/**
* {@inheritDoc}
* @since 1.9
*/
@Override
public IntStream chars() {
// Reuse String-based spliterator. This requires a supplier to
// capture the value and count when the terminal operation is executed
return StreamSupport.intStream(
() -> new String.IntCharArraySpliterator(value, 0, count, 0),
Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED,
false);
}
/**
* {@inheritDoc}
* @since 1.9
*/
@Override
public IntStream codePoints() {
// Reuse String-based spliterator. This requires a supplier to
// capture the value and count when the terminal operation is executed
return StreamSupport.intStream(
() -> new String.CodePointsSpliterator(value, 0, count, 0),
Spliterator.ORDERED,
false);
}
/**
* Needed by {@code String} for the contentEquals method.
*/
final char[] getValue() {
return value;
}
}
{@code
* this.toString().startsWith(str, k)
* }
* If no such value of {@code k} exists, then {@code -1} is returned.
*
* @param str the substring to search for.
* @return the index of the first occurrence of the specified substring,
* or {@code -1} if there is no such occurrence.
*/
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.
*
* {@code
* k >= Math.min(fromIndex, this.length()) &&
* this.toString().startsWith(str, k)
* }
* If no such value of {@code k} exists, then {@code -1} is returned.
*
* @param str the substring to search for.
* @param fromIndex the index from which to start the search.
* @return the index of the first occurrence of the specified substring,
* starting at the specified index,
* or {@code -1} if there is no such occurrence.
*/
public int indexOf(String str, int fromIndex) {
return String.indexOf(value, 0, count, str, fromIndex);
}
/**
* Returns the index within this string of the last occurrence of the
* specified substring. The last occurrence of the empty string "" is
* considered to occur at the index value {@code this.length()}.
*
* {@code
* this.toString().startsWith(str, k)
* }
* If no such value of {@code k} exists, then {@code -1} is returned.
*
* @param str the substring to search for.
* @return the index of the last occurrence of the specified substring,
* or {@code -1} if there is no such occurrence.
*/
public int lastIndexOf(String str) {
return lastIndexOf(str, count);
}
/**
* Returns the index within this string of the last occurrence of the
* specified substring, searching backward starting at the specified index.
*
* {@code
* k <= Math.min(fromIndex, this.length()) &&
* this.toString().startsWith(str, k)
* }
* If no such value of {@code k} exists, then {@code -1} is returned.
*
* @param str the substring to search for.
* @param fromIndex the index to start the search from.
* @return the index of the last occurrence of the specified substring,
* searching backward from the specified index,
* or {@code -1} if there is no such occurrence.
*/
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 n 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 k in the new character sequence is
* equal to the character at index n-k-1 in the old
* character sequence.
*
*