public class ByteArrayInputStream extends InputStream
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
Modifier and Type | Field and Description |
---|---|
protected byte[] |
buf
An array of bytes that was provided
by the creator of the stream.
|
protected int |
count
The index one greater than the last valid character in the input
stream buffer.
|
protected int |
mark
The currently marked position in the stream.
|
protected int |
pos
The index of the next character to read from the input stream buffer.
|
Constructor and Description |
---|
ByteArrayInputStream(byte[] buf)
Creates a
ByteArrayInputStream
so that it uses buf as its
buffer array. |
ByteArrayInputStream(byte[] buf,
int offset,
int length)
Creates
ByteArrayInputStream
that uses buf as its
buffer array. |
Modifier and Type | Method and Description |
---|---|
int |
available()
Returns the number of remaining bytes that can be read (or skipped over)
from this input stream.
|
void |
close()
Closing a ByteArrayInputStream has no effect.
|
void |
mark(int readAheadLimit)
Set the current marked position in the stream.
|
boolean |
markSupported()
Tests if this
InputStream supports mark/reset. |
int |
read()
Reads the next byte of data from this input stream.
|
int |
read(byte[] b,
int off,
int len)
Reads up to
len bytes of data into an array of bytes
from this input stream. |
void |
reset()
Resets the buffer to the marked position.
|
long |
skip(long n)
Skips
n bytes of input from this input stream. |
read
protected byte[] buf
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
count
.
The next byte to be read from the input stream buffer
will be buf[pos]
.protected int mark
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
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)
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)
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()
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)
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)
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()
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()
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)
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()
reset
in class InputStream
InputStream.mark(int)
,
IOException
public void close() throws IOException
close
in interface Closeable
close
in interface AutoCloseable
close
in class InputStream
IOException
- if an I/O error occurs. Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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