- All Implemented Interfaces:
Serializable
,CharSequence
java.lang.StringBuffer
and
java.lang.String
It has a special method getValue() which returns the internal char
array.
Hashcode and equals methods are also implemented.
This AppendingStringBuffer is not synchronized.- Author:
- Johan Compagner
- See Also:
-
Constructor Summary
ConstructorDescriptionConstructs a string buffer with no characters in it and an initial capacity of 16 characters.AppendingStringBuffer
(int length) Constructs a string buffer with no characters in it and an initial capacity specified by thelength
argument.Constructs a string buffer so that it represents the same sequence of characters as the string argument; in other words, the initial contents of the string buffer is a copy of the argument string. -
Method Summary
Modifier and TypeMethodDescriptionappend
(boolean b) Appends the string representation of theboolean
argument to the string buffer.append
(char c) Appends the string representation of thechar
argument to this string buffer.append
(char[] str) Appends the string representation of thechar
array argument to this string buffer.append
(char[] str, int offset, int len) Appends the string representation of a subarray of thechar
array argument to this string buffer.append
(double d) Appends the string representation of thedouble
argument to this string buffer.append
(float f) Appends the string representation of thefloat
argument to this string buffer.append
(int i) Appends the string representation of theint
argument to this string buffer.append
(long l) Appends the string representation of thelong
argument to this string buffer.Appends the string representation of theObject
argument to this string buffer.Appends the string to this string buffer.append
(StringBuilder sb) Appends the specified AppendingStringBuffer to this AppendingStringBuffer.Appends the specified AppendingStringBuffer to this AppendingStringBuffer.int
capacity()
Returns the current capacity of the String buffer.char
charAt
(int index) The specified character of the sequence currently represented by the string buffer, as indicated by theindex
argument, is returned.void
clear()
Clears the buffer contents, but leaves the allocated size intactdelete
(int start, int end) Removes the characters in a substring of thisAppendingStringBuffer
.deleteCharAt
(int index) Removes the character at the specified position in thisAppendingStringBuffer
(shortening theAppendingStringBuffer
by one character).boolean
endsWith
(CharSequence suffix) Tests if this AppendingStringBuffer ends with the specified suffix.void
ensureCapacity
(int minimumCapacity) Ensures that the capacity of the buffer is at least equal to the specified minimum.boolean
Compares this AppendingStringBuffer to the specified object.void
getChars
(int srcBegin, int srcEnd, char[] dst, int dstBegin) Characters are copied from this string buffer into the destination character arraydst
.final char[]
getValue()
This method returns the internal char array.int
hashCode()
Returns a hash code for this AppendingStringBuffer.int
Returns the index within this string of the first occurrence of the specified substring.int
Returns the index within this string of the first occurrence of the specified substring, starting at the specified index.insert
(int offset, boolean b) Inserts the string representation of theboolean
argument into this string buffer.insert
(int offset, char c) Inserts the string representation of thechar
argument into this string buffer.insert
(int offset, char[] str) Inserts the string representation of thechar
array argument into this string buffer.insert
(int index, char[] str, int offset, int len) Inserts the string representation of a subarray of thestr
array argument into this string buffer.insert
(int offset, double d) Inserts the string representation of thedouble
argument into this string buffer.insert
(int offset, float f) Inserts the string representation of thefloat
argument into this string buffer.insert
(int offset, int i) Inserts the string representation of the secondint
argument into this string buffer.insert
(int offset, long l) Inserts the string representation of thelong
argument into this string buffer.Inserts the string representation of theObject
argument into this string buffer.Inserts the string into this string buffer.insert
(int offset, StringBuffer str) Inserts the string into this string buffer.insert
(int offset, StringBuilder str) Inserts the string into this string buffer.int
lastIndexOf
(String str) Returns the index within this string of the rightmost occurrence of the specified substring.int
lastIndexOf
(String str, int fromIndex) Returns the index within this string of the last occurrence of the specified substring.int
length()
Returns the length (character count) of this string buffer.Replaces the characters in a substring of thisAppendingStringBuffer
with characters in the specifiedString
.void
setCharAt
(int index, char ch) The character at the specified index of this string buffer is set toch
.void
setLength
(int newLength) Sets the length of this String buffer.boolean
startsWith
(CharSequence prefix) Tests if this AppendingStringBuffer starts with the specified prefix.boolean
startsWith
(CharSequence prefix, int toffset) Tests if this AppendingStringBuffer starts with the specified prefix beginning a specified index.subSequence
(int start, int end) Returns a new character sequence that is a subsequence of this sequence.substring
(int start) Returns a newString
that contains a subsequence of characters currently contained in thisAppendingStringBuffer
.The substring begins at the specified index and extends to the end of theAppendingStringBuffer
.substring
(int start, int end) Returns a newString
that contains a subsequence of characters currently contained in thisAppendingStringBuffer
.toString()
Converts to a string representing the data in this AppendingStringBuffer.Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.lang.CharSequence
chars, codePoints, isEmpty
-
Constructor Details
-
AppendingStringBuffer
public AppendingStringBuffer()Constructs a string buffer with no characters in it and an initial capacity of 16 characters. -
AppendingStringBuffer
Constructs a string buffer with no characters in it and an initial capacity specified by thelength
argument.- Parameters:
length
- the initial capacity.- Throws:
NegativeArraySizeException
- if thelength
argument is less than0
.
-
AppendingStringBuffer
Constructs a string buffer so that it represents the same sequence of characters as the string argument; in other words, the initial contents of the string buffer is a copy of the argument string. The initial capacity of the string buffer is16
plus the length of the string argument.- Parameters:
str
- the initial contents of the buffer.- Throws:
NullPointerException
- ifstr
isnull
-
-
Method Details
-
length
Returns the length (character count) of this string buffer.- Specified by:
length
in interfaceCharSequence
- Returns:
- the length of the sequence of characters currently represented by this string buffer.
-
capacity
Returns the current capacity of the String buffer. The capacity is the amount of storage available for newly inserted characters; beyond which an allocation will occur.- Returns:
- the current capacity of this string buffer.
-
ensureCapacity
Ensures that the capacity of the buffer is at least equal to the specified minimum. If the current capacity of this string buffer is less than the argument, then a new internal buffer is allocated with greater capacity. The new capacity is the larger of:- The
minimumCapacity
argument. - Twice the old capacity, plus
2
.
minimumCapacity
argument is nonpositive, this method takes no action and simply returns.- Parameters:
minimumCapacity
- the minimum desired capacity.
- The
-
setLength
Sets the length of this String buffer. This string buffer is altered to represent a new character sequence whose length is specified by the argument. For every nonnegative index k less thannewLength
, the character at index k in the new character sequence is the same as the character at index k in the old sequence if k is less than the length of the old character sequence; otherwise, it is the null character'\u0000'
. In other words, if thenewLength
argument is less than the current length of the string buffer, the string buffer is truncated to contain exactly the number of characters given by thenewLength
argument.If the
newLength
argument is greater than or equal to the current length, sufficient null characters ('\u0000'
) are appended to the string buffer so that length becomes thenewLength
argument.The
newLength
argument must be greater than or equal to0
.- Parameters:
newLength
- the new length of the buffer.- Throws:
IndexOutOfBoundsException
- if thenewLength
argument is negative.- See Also:
-
charAt
The specified character of the sequence currently represented by the string buffer, as indicated by theindex
argument, is returned. The first character of a string buffer is at index0
, the next at index1
, and so on, for array indexing.The index argument must be greater than or equal to
0
, and less than the length of this string buffer.- Specified by:
charAt
in interfaceCharSequence
- Parameters:
index
- the index of the desired character.- Returns:
- the character at the specified index of this string buffer.
- Throws:
IndexOutOfBoundsException
- ifindex
is negative or greater than or equal tolength()
.- See Also:
-
getChars
Characters are copied from this string buffer into the destination character arraydst
. The first character to be copied is at indexsrcBegin
; the last character to be copied is at indexsrcEnd-1
. The total number of characters to be copied issrcEnd-srcBegin
. The characters are copied into the subarray ofdst
starting at indexdstBegin
and ending at index:dstbegin + (srcEnd - srcBegin) - 1
- Parameters:
srcBegin
- start copying at this offset in the string buffer.srcEnd
- stop copying at this offset in the string buffer.dst
- the array to copy the data into.dstBegin
- offset intodst
.- Throws:
NullPointerException
- ifdst
isnull
.IndexOutOfBoundsException
- if any of the following is true:srcBegin
is negativedstBegin
is negative- the
srcBegin
argument is greater than thesrcEnd
argument. srcEnd
is greater thanthis.length()
, the current length of this string buffer.dstBegin+srcEnd-srcBegin
is greater thandst.length
-
setCharAt
The character at the specified index of this string buffer is set toch
. The string buffer is altered to represent a new character sequence that is identical to the old character sequence, except that it contains the characterch
at positionindex
.The index argument must be greater than or equal to
0
, and less than the length of this string buffer.- Parameters:
index
- the index of the character to modify.ch
- the new character.- Throws:
IndexOutOfBoundsException
- ifindex
is negative or greater than or equal tolength()
.- See Also:
-
append
Appends the string representation of theObject
argument to this string buffer.The argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then appended to this string buffer.- Parameters:
obj
- anObject
.- Returns:
- a reference to this
AppendingStringBuffer
object. - See Also:
-
append
Appends the string to this string buffer.The characters of the
String
argument are appended, in order, to the contents of this string buffer, increasing the length of this string buffer by the length of the argument. Ifstr
isnull
, then the four characters"null"
are appended to this string buffer.Let n be the length of the old character sequence, the one contained in the string buffer just prior to execution of the
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 argumentstr
.- Parameters:
str
- a string.- Returns:
- a reference to this
AppendingStringBuffer
.
-
append
Appends the specified AppendingStringBuffer to this AppendingStringBuffer.The characters of the AppendingStringBuffer argument are appended, in order, to the contents of this AppendingStringBuffer, increasing the length of this AppendingStringBuffer by the length of the argument. If sb is null , then the four characters "null" are appended to this AppendingStringBuffer.
Let n be the length of the old character sequence, the one contained in the AppendingStringBuffer just prior to execution of the 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
sb
.The method ensureCapacity is first called on this AppendingStringBuffer with the new buffer length as its argument. (This ensures that the storage of this AppendingStringBuffer is adequate to contain the additional characters being appended.)
- Parameters:
sb
- the AppendingStringBuffer to append.- Returns:
- a reference to this AppendingStringBuffer.
- Since:
- 1.4
-
append
Appends the specified AppendingStringBuffer to this AppendingStringBuffer.The characters of the AppendingStringBuffer argument are appended, in order, to the contents of this AppendingStringBuffer, increasing the length of this AppendingStringBuffer by the length of the argument. If sb is null , then the four characters "null" are appended to this AppendingStringBuffer.
Let n be the length of the old character sequence, the one contained in the AppendingStringBuffer just prior to execution of the 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
sb
.The method ensureCapacity is first called on this AppendingStringBuffer with the new buffer length as its argument. (This ensures that the storage of this AppendingStringBuffer is adequate to contain the additional characters being appended.)
- Parameters:
sb
- the AppendingStringBuffer to append.- Returns:
- a reference to this AppendingStringBuffer.
- Since:
- 1.4
-
append
Appends the string representation of thechar
array argument to this string buffer.The characters of the array argument are appended, in order, to the contents of this string buffer. The length of this string buffer increases by the length of the argument.
The overall effect is exactly as if the argument were converted to a string by the method
String.valueOf(char[])
and the characters of that string were thenappended
to thisAppendingStringBuffer
object.- Parameters:
str
- the characters to be appended.- Returns:
- a reference to this
AppendingStringBuffer
object.
-
append
Appends the string representation of a subarray of thechar
array argument to this string buffer.Characters of the character array
str
, starting at indexoffset
, are appended, in order, to the contents of this string buffer. The length of this string buffer increases by the value oflen
.The overall effect is exactly as if the arguments were converted to a string by the method
String.valueOf(char[],int,int)
and the characters of that string were thenappended
to thisAppendingStringBuffer
object.- Parameters:
str
- the characters to be appended.offset
- the index of the first character to append.len
- the number of characters to append.- Returns:
- a reference to this
AppendingStringBuffer
object.
-
append
Appends the string representation of theboolean
argument to the string buffer.The argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then appended to this string buffer.- Parameters:
b
- aboolean
.- Returns:
- a reference to this
AppendingStringBuffer
. - See Also:
-
append
Appends the string representation of thechar
argument to this string buffer.The argument is appended to the contents of this string buffer. The length of this string buffer increases by
1
.The overall effect is exactly as if the argument were converted to a string by the method
String.valueOf(char)
and the character in that string were thenappended
to thisAppendingStringBuffer
object.- Parameters:
c
- achar
.- Returns:
- a reference to this
AppendingStringBuffer
object.
-
append
Appends the string representation of theint
argument to this string buffer.The argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then appended to this string buffer.- Parameters:
i
- anint
.- Returns:
- a reference to this
AppendingStringBuffer
object. - See Also:
-
append
Appends the string representation of thelong
argument to this string buffer.The argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then appended to this string buffer.- Parameters:
l
- along
.- Returns:
- a reference to this
AppendingStringBuffer
object. - See Also:
-
append
Appends the string representation of thefloat
argument to this string buffer.The argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then appended to this string buffer.- Parameters:
f
- afloat
.- Returns:
- a reference to this
AppendingStringBuffer
object. - See Also:
-
append
Appends the string representation of thedouble
argument to this string buffer.The argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then appended to this string buffer.- Parameters:
d
- adouble
.- Returns:
- a reference to this
AppendingStringBuffer
object. - See Also:
-
delete
Removes the characters in a substring of thisAppendingStringBuffer
. The substring begins at the specifiedstart
and extends to the character at indexend - 1
or to the end of theAppendingStringBuffer
if no such character exists. Ifstart
is equal toend
, no changes are made.- Parameters:
start
- The beginning index, inclusive.end
- The ending index, exclusive.- Returns:
- This string buffer.
- Throws:
StringIndexOutOfBoundsException
- ifstart
is negative, greater thanlength()
, or greater thanend
.- Since:
- 1.2
-
deleteCharAt
Removes the character at the specified position in thisAppendingStringBuffer
(shortening theAppendingStringBuffer
by one character).- Parameters:
index
- Index of character to remove- Returns:
- This string buffer.
- Throws:
StringIndexOutOfBoundsException
- if theindex
is negative or greater than or equal tolength()
.- Since:
- 1.2
-
replace
Replaces the characters in a substring of thisAppendingStringBuffer
with characters in the specifiedString
. The substring begins at the specifiedstart
and extends to the character at indexend - 1
or to the end of theAppendingStringBuffer
if no such character exists. First the characters in the substring are removed and then the specifiedString
is inserted atstart
. (TheAppendingStringBuffer
will be lengthened to accommodate the specified String if necessary.)- Parameters:
start
- The beginning index, inclusive.end
- The ending index, exclusive.str
- String that will replace previous contents.- Returns:
- This string buffer.
- Throws:
StringIndexOutOfBoundsException
- ifstart
is negative, greater thanlength()
, or greater thanend
.- Since:
- 1.2
-
substring
Returns a newString
that contains a subsequence of characters currently contained in thisAppendingStringBuffer
.The substring begins at the specified index and extends to the end of theAppendingStringBuffer
.- Parameters:
start
- The beginning index, inclusive.- Returns:
- The new string.
- Throws:
StringIndexOutOfBoundsException
- ifstart
is less than zero, or greater than the length of thisAppendingStringBuffer
.- Since:
- 1.2
-
subSequence
Returns a new character sequence that is a subsequence of this sequence.An invocation of this method of the form
sb.subSequence(begin, end)
sb.substring(begin, end)
CharSequence
interface.- Specified by:
subSequence
in interfaceCharSequence
- Parameters:
start
- the start index, inclusive.end
- the end index, exclusive.- Returns:
- the specified subsequence.
- Throws:
IndexOutOfBoundsException
- if start or end are negative, if end is greater than length(), or if start is greater than end- Since:
- 1.4 Specification: JSR-51
-
substring
Returns a newString
that contains a subsequence of characters currently contained in thisAppendingStringBuffer
. The substring begins at the specifiedstart
and extends to the character at indexend - 1
. An exception is thrown if- Parameters:
start
- The beginning index, inclusive.end
- The ending index, exclusive.- Returns:
- The new string.
- Throws:
StringIndexOutOfBoundsException
- ifstart
orend
are negative or greater thanlength()
, orstart
is greater thanend
.- Since:
- 1.2
-
insert
Inserts the string representation of a subarray of thestr
array argument into this string buffer. The subarray begins at the specifiedoffset
and extendslen
characters. The characters of the subarray are inserted into this string buffer at the position indicated byindex
. The length of thisAppendingStringBuffer
increases bylen
characters.- Parameters:
index
- position at which to insert subarray.str
- A character array.offset
- the index of the first character in subarray to to be inserted.len
- the number of characters in the subarray to to be inserted.- Returns:
- This string buffer.
- Throws:
StringIndexOutOfBoundsException
- ifindex
is negative or greater thanlength()
, oroffset
orlen
are negative, or(offset+len)
is greater thanstr.length
.- Since:
- 1.2
-
insert
Inserts the string representation of theObject
argument into this string buffer.The second argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then inserted into this string buffer at the indicated offset.The offset argument must be greater than or equal to
0
, and less than or equal to the length of this string buffer.- Parameters:
offset
- the offset.obj
- anObject
.- Returns:
- a reference to this
AppendingStringBuffer
object. - Throws:
StringIndexOutOfBoundsException
- if the offset is invalid.- See Also:
-
insert
Inserts the string into this string buffer.The characters of the
String
argument are inserted, in order, into this string buffer at the indicated offset, moving up any characters originally above that position and increasing the length of this string buffer by the length of the argument. Ifstr
isnull
, then the four characters"null"
are inserted into this string buffer.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
offset
- the character at index k
-offset
in the argumentstr
, if k is not less thanoffset
but is less thanoffset+str.length()
- the character at index k
-str.length()
in the old character sequence, if k is not less thanoffset+str.length()
The offset argument must be greater than or equal to
0
, and less than or equal to the length of this string buffer.- Parameters:
offset
- the offset.str
- a string.- Returns:
- a reference to this
AppendingStringBuffer
object. - Throws:
StringIndexOutOfBoundsException
- if the offset is invalid.- See Also:
- the character at index k in the old character sequence, if k is less than
-
insert
Inserts the string into this string buffer.The characters of the
StringBuilder
argument are inserted, in order, into this string buffer at the indicated offset, moving up any characters originally above that position and increasing the length of this string buffer by the length of the argument. Ifstr
isnull
, then the four characters"null"
are inserted into this string buffer.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
offset
- the character at index k
-offset
in the argumentstr
, if k is not less thanoffset
but is less thanoffset+str.length()
- the character at index k
-str.length()
in the old character sequence, if k is not less thanoffset+str.length()
The offset argument must be greater than or equal to
0
, and less than or equal to the length of this string buffer.- Parameters:
offset
- the offset.str
- a string.- Returns:
- a reference to this
AppendingStringBuffer
object. - Throws:
StringIndexOutOfBoundsException
- if the offset is invalid.- See Also:
- the character at index k in the old character sequence, if k is less than
-
insert
Inserts the string into this string buffer.The characters of the
StringBuffer
argument are inserted, in order, into this string buffer at the indicated offset, moving up any characters originally above that position and increasing the length of this string buffer by the length of the argument. Ifstr
isnull
, then the four characters"null"
are inserted into this string buffer.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
offset
- the character at index k
-offset
in the argumentstr
, if k is not less thanoffset
but is less thanoffset+str.length()
- the character at index k
-str.length()
in the old character sequence, if k is not less thanoffset+str.length()
The offset argument must be greater than or equal to
0
, and less than or equal to the length of this string buffer.- Parameters:
offset
- the offset.str
- a string.- Returns:
- a reference to this
AppendingStringBuffer
object. - Throws:
StringIndexOutOfBoundsException
- if the offset is invalid.- See Also:
- the character at index k in the old character sequence, if k is less than
-
insert
Inserts the string representation of thechar
array argument into this string buffer.The characters of the array argument are inserted into the contents of this string buffer at the position indicated by
offset
. The length of this string buffer increases by the length of the argument.The overall effect is exactly as if the argument were converted to a string by the method
String.valueOf(char[])
and the characters of that string were theninserted
into thisAppendingStringBuffer
object at the position indicated byoffset
.- Parameters:
offset
- the offset.str
- a character array.- Returns:
- a reference to this
AppendingStringBuffer
object. - Throws:
StringIndexOutOfBoundsException
- if the offset is invalid.
-
insert
Inserts the string representation of theboolean
argument into this string buffer.The second argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then inserted into this string buffer at the indicated offset.The offset argument must be greater than or equal to
0
, and less than or equal to the length of this string buffer.- Parameters:
offset
- the offset.b
- aboolean
.- Returns:
- a reference to this
AppendingStringBuffer
object. - Throws:
StringIndexOutOfBoundsException
- if the offset is invalid.- See Also:
-
insert
Inserts the string representation of thechar
argument into this string buffer.The second argument is inserted into the contents of this string buffer at the position indicated by
offset
. The length of this string buffer increases by one.The overall effect is exactly as if the argument were converted to a string by the method
String.valueOf(char)
and the character in that string were theninserted
into thisAppendingStringBuffer
object at the position indicated byoffset
.The offset argument must be greater than or equal to
0
, and less than or equal to the length of this string buffer.- Parameters:
offset
- the offset.c
- achar
.- Returns:
- a reference to this
AppendingStringBuffer
object. - Throws:
IndexOutOfBoundsException
- if the offset is invalid.- See Also:
-
insert
Inserts the string representation of the secondint
argument into this string buffer.The second argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then inserted into this string buffer at the indicated offset.The offset argument must be greater than or equal to
0
, and less than or equal to the length of this string buffer.- Parameters:
offset
- the offset.i
- anint
.- Returns:
- a reference to this
AppendingStringBuffer
object. - Throws:
StringIndexOutOfBoundsException
- if the offset is invalid.- See Also:
-
insert
Inserts the string representation of thelong
argument into this string buffer.The second argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then inserted into this string buffer at the position indicated byoffset
.The offset argument must be greater than or equal to
0
, and less than or equal to the length of this string buffer.- Parameters:
offset
- the offset.l
- along
.- Returns:
- a reference to this
AppendingStringBuffer
object. - Throws:
StringIndexOutOfBoundsException
- if the offset is invalid.- See Also:
-
insert
Inserts the string representation of thefloat
argument into this string buffer.The second argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then inserted into this string buffer at the indicated offset.The offset argument must be greater than or equal to
0
, and less than or equal to the length of this string buffer.- Parameters:
offset
- the offset.f
- afloat
.- Returns:
- a reference to this
AppendingStringBuffer
object. - Throws:
StringIndexOutOfBoundsException
- if the offset is invalid.- See Also:
-
insert
Inserts the string representation of thedouble
argument into this string buffer.The second argument is converted to a string as if by the method
String.valueOf
, and the characters of that string are then inserted into this string buffer at the indicated offset.The offset argument must be greater than or equal to
0
, and less than or equal to the length of this string buffer.- Parameters:
offset
- the offset.d
- adouble
.- Returns:
- a reference to this
AppendingStringBuffer
object. - Throws:
StringIndexOutOfBoundsException
- if the offset is invalid.- See Also:
-
indexOf
Returns the index within this string of the first occurrence of the specified substring. The integer returned is the smallest value k such that:this.toString().startsWith(str, <i>k</i>)
true
.- Parameters:
str
- any string.- Returns:
- if the string argument occurs as a substring within this object, then the index of
the first character of the first such substring is returned; if it does not occur as
a substring,
-1
is returned. - Throws:
NullPointerException
- ifstr
isnull
.- Since:
- 1.4
-
indexOf
Returns the index within this string of the first occurrence of the specified substring, starting at the specified index. The integer returned is the smallest value k for which:k >= Math.min(fromIndex, str.length()) && this.toString().startsWith(str, k)
- Parameters:
str
- the substring for which to search.fromIndex
- the index from which to start the search.- Returns:
- the index within this string of the first occurrence of the specified substring, starting at the specified index.
- Throws:
NullPointerException
- ifstr
isnull
.- Since:
- 1.4
-
lastIndexOf
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 valuethis.length()
. The returned index is the largest value k such thatthis.toString().startsWith(str, k)
- Parameters:
str
- the substring to search for.- Returns:
- 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,
-1
is returned. - Throws:
NullPointerException
- ifstr
isnull
.- Since:
- 1.4
-
lastIndexOf
Returns the index within this string of the last occurrence of the specified substring. The integer returned is the largest value k such that:k <= Math.min(fromIndex, str.length()) && this.toString().startsWith(str, k)
- Parameters:
str
- the substring to search for.fromIndex
- the index to start the search from.- Returns:
- the index within this string of the last occurrence of the specified substring.
- Throws:
NullPointerException
- ifstr
isnull
.- Since:
- 1.4
-
startsWith
Tests if this AppendingStringBuffer starts with the specified prefix beginning a specified index.- Parameters:
prefix
- the prefix.toffset
- where to begin looking in the string.- Returns:
true
if the character sequence represented by the argument is a prefix of the substring of this object starting at indextoffset
;false
otherwise. The result isfalse
iftoffset
is negative or greater than the length of thisString
object; otherwise the result is the same as the result of the expressionthis.subString(toffset).startsWith(prefix)
-
startsWith
Tests if this AppendingStringBuffer starts with the specified prefix.- Parameters:
prefix
- the prefix.- Returns:
true
if the character sequence represented by the argument is a prefix of the character sequence represented by this AppendingStringBuffer;false
otherwise. Note also thattrue
will be returned if the argument is an empty string or is equal to thisAppendingStringBuffer
object as determined by theequals(Object)
method.- Since:
- 1. 0
-
endsWith
Tests if this AppendingStringBuffer ends with the specified suffix.- Parameters:
suffix
- the suffix.- Returns:
true
if the character sequence represented by the argument is a suffix of the character sequence represented by this AppendingStringBuffer;false
otherwise. Note that the result will betrue
if the argument is the empty string or is equal to thisAppendingStringBuffer
object as determined by theequals(Object)
method.
-
toString
Converts to a string representing the data in this AppendingStringBuffer. A newString
object is allocated and initialized to contain the character sequence currently represented by this string buffer. ThisString
is then returned. Subsequent changes to the string buffer do not affect the contents of theString
.Implementation advice: This method can be coded so as to create a new
String
object without allocating new memory to hold a copy of the character sequence. Instead, the string can share the memory used by the string buffer. Any subsequent operation that alters the content or capacity of the string buffer must then make a copy of the internal buffer at that time. This strategy is effective for reducing the amount of memory allocated by a string concatenation operation when it is implemented using a string buffer.- Specified by:
toString
in interfaceCharSequence
- Overrides:
toString
in classObject
- Returns:
- a string representation of the string buffer.
-
getValue
This method returns the internal char array. So it is not- Returns:
- The internal char array
-
equals
Compares this AppendingStringBuffer to the specified object. The result istrue
if and only if the argument is notnull
and is aAppendingStringBuffer
object or another charsequence object! that represents the same sequence of characters as this object. -
hashCode
Returns a hash code for this AppendingStringBuffer. The hash code for aAppendingStringBuffer
object is computed ass[0]*31ˆ(n-1) + s[1]*31ˆ(n-2) + ... + s[n-1]
int
arithmetic, wheres[i]
is the ith character of the AppendingStringBuffer,n
is the length of the AppendingStringBuffer, and^
indicates exponentiation. (The hash value of the empty AppendingStringBuffer is zero.) -
clear
Clears the buffer contents, but leaves the allocated size intact
-