| java.lang.Object
 java.lang.AbstractStringBuilder
java.lang.StringBuffer
| StringBuffer | | final public class StringBuffer extends AbstractStringBuilder implements java.io.Serializable,CharSequence(Code) | | A thread-safe, mutable sequence of characters.
A string buffer is like a
String , but can be modified. 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.
String buffers are safe for use by multiple threads. The methods
are synchronized where necessary so that all the operations on any
particular instance behave as if they occur in some serial order
that is consistent with the order of the method calls made by each of
the individual threads involved.
The principal operations on a StringBuffer are the
append and insert methods, which are
overloaded so as to accept data of any type. Each effectively
converts a given datum to a string and then appends or inserts the
characters of that string to the string buffer. The
append method always adds these characters at the end
of the buffer; the insert method adds the characters at
a specified point.
For example, if z refers to a string buffer object
whose current contents are "start", then
the method call z.append("le") would cause the string
buffer to contain "startle", whereas
z.insert(4, "le") would alter the string buffer to
contain "starlet".
In general, if sb refers to an instance of a StringBuffer,
then sb.append(x) has the same effect as
sb.insert(sb.length(), x).
Whenever an operation occurs involving a source sequence (such as
appending or inserting from a source sequence) this class synchronizes
only on the string buffer performing the operation, not on the source.
Every string buffer has a capacity. As long as the length of the
character sequence contained in the string buffer does not exceed
the capacity, it is not necessary to allocate a new internal
buffer array. If the internal buffer overflows, it is
automatically made larger.
As of release JDK 5, this class has been supplemented with an equivalent
class designed for use by a single thread,
StringBuilder . The
StringBuilder class should generally be used in preference to
this one, as it supports all of the same operations but it is faster, as
it performs no synchronization.
author:
Arthur van Hoff
version:
1.107, 05/05/07
See Also: java.lang.StringBuilder
See Also: java.lang.String
since:
JDK1.0 |
| Constructor Summary | |
| public | StringBuffer()
Constructs a string buffer with no characters in it and an
initial capacity of 16 characters. | | public | StringBuffer(int capacity)
Constructs a string buffer with no characters in it and
the specified initial capacity. | | public | StringBuffer(String str)
Constructs a string buffer initialized to the contents of the
specified string. | | public | StringBuffer(CharSequence seq)
Constructs a string buffer that contains the same characters
as the specified CharSequence. |
| Method Summary | |
| public synchronized StringBuffer | append(Object obj)
| | public synchronized StringBuffer | append(String str)
| | public synchronized StringBuffer | append(StringBuffer sb)
Appends the specified StringBuffer to this sequence.
The characters of the StringBuffer argument are appended,
in order, to the contents of this StringBuffer, increasing the
length of this StringBuffer by the length of the argument. | | public StringBuffer | append(CharSequence s)
Appends the specified CharSequence to this
sequence.
The characters of the CharSequence argument are appended,
in order, increasing the length of this sequence by the length of the
argument.
The result of this method is exactly the same as if it were an
invocation of this.append(s, 0, s.length());
This method synchronizes on this (the destination)
object but does not synchronize on the source (s).
If s is null, then the four characters
"null" are appended.
Parameters:
s - the CharSequence to append. | | public synchronized StringBuffer | append(CharSequence s, int start, int end)
| | public synchronized StringBuffer | append(char str)
| | public synchronized StringBuffer | append(char str, int offset, int len)
| | public synchronized StringBuffer | append(boolean b)
| | public synchronized StringBuffer | append(char c)
| | public synchronized StringBuffer | append(int i)
| | public synchronized StringBuffer | append(long lng)
| | public synchronized StringBuffer | append(float f)
| | public synchronized StringBuffer | append(double d)
| | public synchronized StringBuffer | appendCodePoint(int codePoint)
| | public synchronized int | capacity()
| | public synchronized char | charAt(int index)
| | public synchronized int | codePointAt(int index)
| | public synchronized int | codePointBefore(int index)
| | public synchronized int | codePointCount(int beginIndex, int endIndex)
| | public synchronized StringBuffer | delete(int start, int end)
| | public synchronized StringBuffer | deleteCharAt(int index)
| | public synchronized void | ensureCapacity(int minimumCapacity)
| | public synchronized void | getChars(int srcBegin, int srcEnd, char dst, int dstBegin)
| | public int | indexOf(String str)
| | public synchronized int | indexOf(String str, int fromIndex)
| | public synchronized StringBuffer | insert(int index, char str, int offset, int len)
| | public synchronized StringBuffer | insert(int offset, Object obj)
| | public synchronized StringBuffer | insert(int offset, String str)
| | public synchronized StringBuffer | insert(int offset, char str)
| | public StringBuffer | insert(int dstOffset, CharSequence s)
| | public synchronized StringBuffer | insert(int dstOffset, CharSequence s, int start, int end)
| | public StringBuffer | insert(int offset, boolean b)
| | public synchronized StringBuffer | insert(int offset, char c)
| | public StringBuffer | insert(int offset, int i)
| | public StringBuffer | insert(int offset, long l)
| | public StringBuffer | insert(int offset, float f)
| | public StringBuffer | insert(int offset, double d)
| | public int | lastIndexOf(String str)
| | public synchronized int | lastIndexOf(String str, int fromIndex)
| | public synchronized int | length()
| | public synchronized int | offsetByCodePoints(int index, int codePointOffset)
| | public synchronized StringBuffer | replace(int start, int end, String str)
| | public synchronized StringBuffer | reverse()
| | public synchronized void | setCharAt(int index, char ch)
| | public synchronized void | setLength(int newLength)
| | public synchronized CharSequence | subSequence(int start, int end)
| | public synchronized String | substring(int start)
| | public synchronized String | substring(int start, int end)
| | public synchronized String | toString()
| | public synchronized void | trimToSize()
|
| serialVersionUID | | final static long serialVersionUID(Code) | | use serialVersionUID from JDK 1.0.2 for interoperability
|
| StringBuffer | | public StringBuffer()(Code) | | Constructs a string buffer with no characters in it and an
initial capacity of 16 characters.
|
| StringBuffer | | public StringBuffer(int capacity)(Code) | | Constructs a string buffer with no characters in it and
the specified initial capacity.
Parameters:
capacity - the initial capacity.
exception:
NegativeArraySizeException - if the capacityargument is less than 0. |
| StringBuffer | | public StringBuffer(String str)(Code) | | Constructs a string buffer initialized to the contents of the
specified string. The initial capacity of the string buffer is
16 plus the length of the string argument.
Parameters:
str - the initial contents of the buffer.
exception:
NullPointerException - if str is null |
| StringBuffer | | public StringBuffer(CharSequence seq)(Code) | | Constructs a string buffer that contains the same characters
as the specified CharSequence. The initial capacity of
the string buffer is 16 plus the length of the
CharSequence argument.
If the length of the specified CharSequence is
less than or equal to zero, then an empty buffer of capacity
16 is returned.
Parameters:
seq - the sequence to copy.
exception:
NullPointerException - if seq is null
since:
1.5 |
| append | | public synchronized StringBuffer append(StringBuffer sb)(Code) | | Appends the specified StringBuffer to this sequence.
The characters of the StringBuffer argument are appended,
in order, to the contents of this StringBuffer, increasing the
length of this StringBuffer by the length of the argument.
If sb is null, then the four characters
"null" are appended to this StringBuffer.
Let n be the length of the old character sequence, the one
contained in the StringBuffer 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.
This method synchronizes on this (the destination)
object but does not synchronize on the source (sb).
Parameters:
sb - the StringBuffer to append. a reference to this object.
since:
1.4 |
| append | | public StringBuffer append(CharSequence s)(Code) | | Appends the specified CharSequence to this
sequence.
The characters of the CharSequence argument are appended,
in order, increasing the length of this sequence by the length of the
argument.
The result of this method is exactly the same as if it were an
invocation of this.append(s, 0, s.length());
This method synchronizes on this (the destination)
object but does not synchronize on the source (s).
If s is null, then the four characters
"null" are appended.
Parameters:
s - the CharSequence to append. a reference to this object.
since:
1.5 |
| appendCodePoint | | public synchronized StringBuffer appendCodePoint(int codePoint)(Code) | |
since:
1.5 |
| capacity | | public synchronized int capacity()(Code) | | |
| codePointAt | | public synchronized int codePointAt(int index)(Code) | |
since:
1.5 |
| codePointBefore | | public synchronized int codePointBefore(int index)(Code) | |
since:
1.5 |
| codePointCount | | public synchronized int codePointCount(int beginIndex, int endIndex)(Code) | |
since:
1.5 |
| ensureCapacity | | public synchronized void ensureCapacity(int minimumCapacity)(Code) | | |
| length | | public synchronized int length()(Code) | | |
| offsetByCodePoints | | public synchronized int offsetByCodePoints(int index, int codePointOffset)(Code) | |
since:
1.5 |
| trimToSize | | public synchronized void trimToSize()(Code) | |
since:
1.5 |
| Methods inherited from java.lang.AbstractStringBuilder | public AbstractStringBuilder append(Object obj)(Code)(Java Doc)
public AbstractStringBuilder append(String str)(Code)(Java Doc)
public AbstractStringBuilder append(StringBuffer sb)(Code)(Java Doc)
public AbstractStringBuilder append(CharSequence s)(Code)(Java Doc)
public AbstractStringBuilder append(CharSequence s, int start, int end)(Code)(Java Doc)
public AbstractStringBuilder append(char str)(Code)(Java Doc)
public AbstractStringBuilder append(char str, int offset, int len)(Code)(Java Doc)
public AbstractStringBuilder append(boolean b)(Code)(Java Doc)
public AbstractStringBuilder append(char c)(Code)(Java Doc)
public AbstractStringBuilder append(int i)(Code)(Java Doc)
public AbstractStringBuilder append(long l)(Code)(Java Doc)
public AbstractStringBuilder append(float f)(Code)(Java Doc)
public AbstractStringBuilder append(double d)(Code)(Java Doc)
public AbstractStringBuilder appendCodePoint(int codePoint)(Code)(Java Doc)
public int capacity()(Code)(Java Doc)
public char charAt(int index)(Code)(Java Doc)
public int codePointAt(int index)(Code)(Java Doc)
public int codePointBefore(int index)(Code)(Java Doc)
public int codePointCount(int beginIndex, int endIndex)(Code)(Java Doc)
public AbstractStringBuilder delete(int start, int end)(Code)(Java Doc)
public AbstractStringBuilder deleteCharAt(int index)(Code)(Java Doc)
public void ensureCapacity(int minimumCapacity)(Code)(Java Doc)
void expandCapacity(int minimumCapacity)(Code)(Java Doc)
public void getChars(int srcBegin, int srcEnd, char dst, int dstBegin)(Code)(Java Doc)
final char[] getValue()(Code)(Java Doc)
public int indexOf(String str)(Code)(Java Doc)
public int indexOf(String str, int fromIndex)(Code)(Java Doc)
public AbstractStringBuilder insert(int index, char str, int offset, int len)(Code)(Java Doc)
public AbstractStringBuilder insert(int offset, Object obj)(Code)(Java Doc)
public AbstractStringBuilder insert(int offset, String str)(Code)(Java Doc)
public AbstractStringBuilder insert(int offset, char str)(Code)(Java Doc)
public AbstractStringBuilder insert(int dstOffset, CharSequence s)(Code)(Java Doc)
public AbstractStringBuilder insert(int dstOffset, CharSequence s, int start, int end)(Code)(Java Doc)
public AbstractStringBuilder insert(int offset, boolean b)(Code)(Java Doc)
public AbstractStringBuilder insert(int offset, char c)(Code)(Java Doc)
public AbstractStringBuilder insert(int offset, int i)(Code)(Java Doc)
public AbstractStringBuilder insert(int offset, long l)(Code)(Java Doc)
public AbstractStringBuilder insert(int offset, float f)(Code)(Java Doc)
public AbstractStringBuilder insert(int offset, double d)(Code)(Java Doc)
public int lastIndexOf(String str)(Code)(Java Doc)
public int lastIndexOf(String str, int fromIndex)(Code)(Java Doc)
public int length()(Code)(Java Doc)
public int offsetByCodePoints(int index, int codePointOffset)(Code)(Java Doc)
public AbstractStringBuilder replace(int start, int end, String str)(Code)(Java Doc)
public AbstractStringBuilder reverse()(Code)(Java Doc)
public void setCharAt(int index, char ch)(Code)(Java Doc)
public void setLength(int newLength)(Code)(Java Doc)
public CharSequence subSequence(int start, int end)(Code)(Java Doc)
public String substring(int start)(Code)(Java Doc)
public String substring(int start, int end)(Code)(Java Doc)
abstract public String toString()(Code)(Java Doc)
public void trimToSize()(Code)(Java Doc)
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