public class ByteArrayInputStream extends InputStream
A ByteArrayInputStream
contains an internal buffer that contains bytes that may be read from the stream. An internal counter keeps track of the next byte to be supplied by the read
method.
Closing a ByteArrayInputStream
has no effect. The methods in this class can be called after the stream has been closed without generating an IOException
.
StringBufferInputStream
protected byte[] buf
An array of bytes that was provided by the creator of the stream. Elements buf[0]
through buf[count-1]
are the only bytes that can ever be read from the stream; element buf[pos]
is the next byte to be read.
protected int pos
The index of the next character to read from the input stream buffer. This value should always be nonnegative and not larger than the value of count
. The next byte to be read from the input stream buffer will be buf[pos]
.
protected int mark
The currently marked position in the stream. ByteArrayInputStream objects are marked at position zero by default when constructed. They may be marked at another position within the buffer by the mark()
method. The current buffer position is set to this point by the reset()
method.
If no mark has been set, then the value of mark is the offset passed to the constructor (or 0 if the offset was not supplied).
protected int count
The index one greater than the last valid character in the input stream buffer. This value should always be nonnegative and not larger than the length of buf
. It is one greater than the position of the last byte within buf
that can ever be read from the input stream buffer.
public ByteArrayInputStream(byte[] buf)
Creates a ByteArrayInputStream
so that it uses buf
as its buffer array. The buffer array is not copied. The initial value of pos
is 0
and the initial value of count
is the length of buf
.
buf
- the input buffer.public ByteArrayInputStream(byte[] buf, int offset, int length)
Creates ByteArrayInputStream
that uses buf
as its buffer array. The initial value of pos
is offset
and the initial value of count
is the minimum of offset+length
and buf.length
. The buffer array is not copied. The buffer's mark is set to the specified offset.
buf
- the input buffer.offset
- the offset in the buffer of the first byte to read.length
- the maximum number of bytes to read from the buffer.public int read()
Reads the next byte of data from this input stream. The value byte is returned as an int
in the range 0
to 255
. If no byte is available because the end of the stream has been reached, the value -1
is returned.
This read
method cannot block.
read
in class InputStream
-1
if the end of the stream has been reached.public int read(byte[] b, int off, int len)
Reads up to len
bytes of data into an array of bytes from this input stream. If pos
equals count
, then -1
is returned to indicate end of file. Otherwise, the number k
of bytes read is equal to the smaller of len
and count-pos
. If k
is positive, then bytes buf[pos]
through buf[pos+k-1]
are copied into b[off]
through b[off+k-1]
in the manner performed by System.arraycopy
. The value k
is added into pos
and k
is returned.
This read
method cannot block.
read
in class InputStream
b
- the buffer into which the data is read.off
- the start offset in the destination array b
len
- the maximum number of bytes read.-1
if there is no more data because the end of the stream has been reached.NullPointerException
- If b
is null
.IndexOutOfBoundsException
- If off
is negative, len
is negative, or len
is greater than b.length - off
InputStream.read()
public long skip(long n)
Skips n
bytes of input from this input stream. Fewer bytes might be skipped if the end of the input stream is reached. The actual number k
of bytes to be skipped is equal to the smaller of n
and count-pos
. The value k
is added into pos
and k
is returned.
skip
in class InputStream
n
- the number of bytes to be skipped.public int available()
Returns the number of remaining bytes that can be read (or skipped over) from this input stream.
The value returned is count - pos
, which is the number of bytes remaining to be read from the input buffer.
available
in class InputStream
public boolean markSupported()
Tests if this InputStream
supports mark/reset. The markSupported
method of ByteArrayInputStream
always returns true
.
markSupported
in class InputStream
true
if this stream instance supports the mark and reset methods; false
otherwise.InputStream.mark(int)
, InputStream.reset()
public void mark(int readAheadLimit)
Set the current marked position in the stream. ByteArrayInputStream objects are marked at position zero by default when constructed. They may be marked at another position within the buffer by this method.
If no mark has been set, then the value of the mark is the offset passed to the constructor (or 0 if the offset was not supplied).
Note: The readAheadLimit
for this class has no meaning.
mark
in class InputStream
readAheadLimit
- the maximum limit of bytes that can be read before the mark position becomes invalid.InputStream.reset()
public void reset()
Resets the buffer to the marked position. The marked position is 0 unless another position was marked or an offset was specified in the constructor.
reset
in class InputStream
InputStream.mark(int)
, IOException
public void close() throws IOException
Closing a ByteArrayInputStream
has no effect. The methods in this class can be called after the stream has been closed without generating an IOException
.
close
in interface Closeable
close
in interface AutoCloseable
close
in class InputStream
IOException
- if an I/O error occurs.
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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