ByteArrayOutputStream
public
class
ByteArrayOutputStream
extends OutputStream
java.lang.Object | ||
↳ | java.io.OutputStream | |
↳ | java.io.ByteArrayOutputStream |
This class implements an output stream in which the data is
written into a byte array. The buffer automatically grows as data
is written to it.
The data can be retrieved using toByteArray()
and
toString()
.
Closing a ByteArrayOutputStream
has no effect. The methods in
this class can be called after the stream has been closed without
generating an IOException
.
Summary
Fields | |
---|---|
protected
byte[] |
buf
The buffer where data is stored. |
protected
int |
count
The number of valid bytes in the buffer. |
Public constructors | |
---|---|
ByteArrayOutputStream()
Creates a new |
|
ByteArrayOutputStream(int size)
Creates a new |
Public methods | |
---|---|
void
|
close()
Closing a |
void
|
reset()
Resets the |
int
|
size()
Returns the current size of the buffer. |
byte[]
|
toByteArray()
Creates a newly allocated byte array. |
String
|
toString(String charsetName)
Converts the buffer's contents into a string by decoding the bytes using
the named |
String
|
toString(Charset charset)
Converts the buffer's contents into a string by decoding the bytes using
the specified |
String
|
toString()
Converts the buffer's contents into a string decoding bytes using the platform's default character set. |
String
|
toString(int hibyte)
This method was deprecated
in API level 15.
This method does not properly convert bytes into characters.
As of JDK 1.1, the preferred way to do this is via the
|
void
|
write(byte[] b, int off, int len)
Writes |
void
|
write(int b)
Writes the specified byte to this |
void
|
writeBytes(byte[] b)
Writes the complete contents of the specified byte array
to this |
void
|
writeTo(OutputStream out)
Writes the complete contents of this |
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Fields
Public constructors
ByteArrayOutputStream
public ByteArrayOutputStream ()
Creates a new ByteArrayOutputStream
. The buffer capacity is
initially 32 bytes, though its size increases if necessary.
ByteArrayOutputStream
public ByteArrayOutputStream (int size)
Creates a new ByteArrayOutputStream
, with a buffer capacity of
the specified size, in bytes.
Parameters | |
---|---|
size |
int : the initial size. |
Throws | |
---|---|
IllegalArgumentException |
if size is negative. |
Public methods
close
public void close ()
Closing a ByteArrayOutputStream
has no effect. The methods in
this class can be called after the stream has been closed without
generating an IOException
.
Throws | |
---|---|
IOException |
reset
public void reset ()
Resets the count
field of this ByteArrayOutputStream
to zero, so that all currently accumulated output in the
output stream is discarded. The output stream can be used again,
reusing the already allocated buffer space.
See also:
size
public int size ()
Returns the current size of the buffer.
Returns | |
---|---|
int |
the value of the count field, which is the number
of valid bytes in this output stream. |
See also:
toByteArray
public byte[] toByteArray ()
Creates a newly allocated byte array. Its size is the current size of this output stream and the valid contents of the buffer have been copied into it.
Returns | |
---|---|
byte[] |
the current contents of this output stream, as a byte array. |
See also:
toString
public String toString (String charsetName)
Converts the buffer's contents into a string by decoding the bytes using
the named charset
.
This method is equivalent to #toString(charset)
that takes a
charset
.
An invocation of this method of the form
ByteArrayOutputStream b = ...
b.toString("UTF-8")
ByteArrayOutputStream b = ...
b.toString(StandardCharsets.UTF_8)
Parameters | |
---|---|
charsetName |
String : the name of a supported
charset |
Returns | |
---|---|
String |
String decoded from the buffer's contents. |
Throws | |
---|---|
UnsupportedEncodingException |
If the named charset is not supported |
toString
public String toString (Charset charset)
Converts the buffer's contents into a string by decoding the bytes using
the specified charset
. The length of the new
String
is a function of the charset, and hence may not be equal
to the length of the byte array.
This method always replaces malformed-input and unmappable-character
sequences with the charset's default replacement string. The CharsetDecoder
class should be used when more control
over the decoding process is required.
Parameters | |
---|---|
charset |
Charset : the charset
to be used to decode the bytes |
Returns | |
---|---|
String |
String decoded from the buffer's contents. |
toString
public String toString ()
Converts the buffer's contents into a string decoding bytes using the
platform's default character set. The length of the new String
is a function of the character set, and hence may not be equal to the
size of the buffer.
This method always replaces malformed-input and unmappable-character sequences with the default replacement string for the platform's default character set. The CharsetDecoder class should be used when more control over the decoding process is required.
Returns | |
---|---|
String |
String decoded from the buffer's contents. |
toString
public String toString (int hibyte)
This method was deprecated
in API level 15.
This method does not properly convert bytes into characters.
As of JDK 1.1, the preferred way to do this is via the
toString(java.lang.String)
or toString(java.nio.charset.Charset)
method, which takes an encoding-name or charset argument,
or the toString()
method, which uses the platform's default
character encoding.
Creates a newly allocated string. Its size is the current size of the output stream and the valid contents of the buffer have been copied into it. Each character c in the resulting string is constructed from the corresponding element b in the byte array such that:
c == (char)(((hibyte & 0xff) << 8) | (b & 0xff))
Parameters | |
---|---|
hibyte |
int : the high byte of each resulting Unicode character. |
Returns | |
---|---|
String |
the current contents of the output stream, as a string. |
See also:
write
public void write (byte[] b, int off, int len)
Writes len
bytes from the specified byte array
starting at offset off
to this ByteArrayOutputStream
.
Parameters | |
---|---|
b |
byte : the data. |
off |
int : the start offset in the data. |
len |
int : the number of bytes to write. |
Throws | |
---|---|
NullPointerException |
if b is null . |
IndexOutOfBoundsException |
if off is negative,
len is negative, or len is greater than
b.length - off |
write
public void write (int b)
Writes the specified byte to this ByteArrayOutputStream
.
Parameters | |
---|---|
b |
int : the byte to be written. |
writeBytes
public void writeBytes (byte[] b)
Writes the complete contents of the specified byte array
to this ByteArrayOutputStream
.
API Note:
- This method is equivalent to
write(b, 0, b.length)
.
Parameters | |
---|---|
b |
byte : the data. |
Throws | |
---|---|
NullPointerException |
if b is null . |
writeTo
public void writeTo (OutputStream out)
Writes the complete contents of this ByteArrayOutputStream
to
the specified output stream argument, as if by calling the output
stream's write method using out.write(buf, 0, count)
.
Parameters | |
---|---|
out |
OutputStream : the output stream to which to write the data. |
Throws | |
---|---|
NullPointerException |
if out is null . |
IOException |
if an I/O error occurs. |