java.io
Class ByteArrayOutputStream
java.lang.Object
|
+--java.io.OutputStream
|
+--java.io.ByteArrayOutputStream
This class allows data to be written to a byte array buffer and
and then retrieved by an application. The internal byte array
buffer is dynamically resized to hold all the data written. Please
be aware that writing large amounts to data to this stream will
cause large amounts of memory to be allocated.
The size of the internal buffer defaults to 32 and it is resized
by doubling the size of the buffer. This default size can be
overridden by using the
gnu.java.io.ByteArrayOutputStream.initialBufferSize
property.
There is a constructor that specified the initial buffer size and
that is the preferred way to set that value because it it portable
across all Java class library implementations.
Note that this class also has methods that convert the byte array
buffer to a String
using either the system default or an
application specified character encoding. Thus it can handle
multibyte character encodings.
Authors:- Aaron M. Renn (arenn@urbanophile.com)
- Tom Tromey <tromey@cygnus.com>
buf
protected byte[] buf
The internal buffer where the data written is stored
count
protected int count
The number of bytes that have been written to the buffer
ByteArrayOutputStream
public ByteArrayOutputStream()
This method initializes a new ByteArrayOutputStream
with the default buffer size of 32 bytes. If a different initial
buffer size is desired, see the constructor
ByteArrayOutputStream(int size)
. For applications
where the source code is not available, the default buffer size
can be set using the system property
gnu.java.io.ByteArrayOutputStream.initialBufferSize
ByteArrayOutputStream
public ByteArrayOutputStream(int size)
This method initializes a new ByteArrayOutputStream
with
a specified initial buffer size.
Parameters:
reset
public synchronized void reset()
This method discards all of the bytes that have been written to
the internal buffer so far by setting the count
variable to 0. The internal buffer remains at its currently
allocated size.
size
public int size()
This method returns the number of bytes that have been written to
the buffer so far. This is the same as the value of the protected
count
variable. If the reset
method is
called, then this value is reset as well. Note that this method does
not return the length of the internal buffer, but only the number
of bytes that have been written to it.
Returns:
- The number of bytes in the internal buffer
See Also:
toByteArray
public synchronized byte[] toByteArray()
This method returns a byte array containing the bytes that have been
written to this stream so far. This array is a copy of the valid
bytes in the internal buffer and its length is equal to the number of
valid bytes, not necessarily to the the length of the current
internal buffer. Note that since this method allocates a new array,
it should be used with caution when the internal buffer is very large.
toString
public String toString()
Returns the bytes in the internal array as a String
. The
bytes in the buffer are converted to characters using the system default
encoding. There is an overloaded toString()
method that
allows an application specified character encoding to be used.
Returns:
- A
String
containing the data written to this
stream so far
toString
public String toString(int hibyte)
This method returns the bytes in the internal array as a
String
. It uses each byte in the array as the low
order eight bits of the Unicode character value and the passed in
parameter as the high eight bits.
This method does not convert bytes to characters in the proper way and
so is deprecated in favor of the other overloaded toString
methods which use a true character encoding.
Parameters:
Returns:
- A
String
containing the data written to this
stream so far
toString
public String toString(java.lang.String enc)
Returns the bytes in the internal array as a String
. The
bytes in the buffer are converted to characters using the specified
encoding.
Parameters:
Returns:
- A
String
containing the data written to this
stream so far
Throws:
write
public synchronized void write(byte[] buffer, int offset, int add)
This method writes len
bytes from the passed in array
buf
starting at index offset
into the
internal buffer.
Parameters:
write
public synchronized void write(int oneByte)
This method writes the writes the specified byte into the internal
buffer.
Parameters:
writeTo
public synchronized void writeTo(java.io.OutputStream out)
This method writes all the bytes that have been written to this stream
from the internal buffer to the specified OutputStream
.
Parameters:
Throws:
The size of the internal buffer defaults to 32 and it is resized by doubling the size of the buffer. This default size can be overridden by using the
gnu.java.io.ByteArrayOutputStream.initialBufferSize
property.There is a constructor that specified the initial buffer size and that is the preferred way to set that value because it it portable across all Java class library implementations.
Note that this class also has methods that convert the byte array buffer to a
String
using either the system default or an application specified character encoding. Thus it can handle multibyte character encodings.