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.
| 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. |
readprotected 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 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.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 pos
count. The next byte to
be read from the input stream buffer will be buf[pos].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 available()
The value returned is count - pos, which is the number of bytes remaining
to be read from the input buffer.
available in class InputStreampublic void close()
throws IOException
close in interface Closeableclose in interface AutoCloseableclose in class InputStreamIOException - if an I/O error occurs.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 InputStreamreadAheadLimit - the maximum limit of bytes that can be read before the mark position becomes invalid.InputStream.reset()public boolean markSupported()
InputStream supports mark/reset. The markSupported
method of ByteArrayInputStream always returns true.markSupported in class InputStreamtrue if this stream instance supports the mark and reset methods;
false otherwise.InputStream.mark(int),
InputStream.reset()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 InputStreamb - the buffer into which the data is read.off - the start offset in the destination array blen - 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 - offInputStream.read()public void reset()
reset in class InputStreamInputStream.mark(int),
IOExceptionpublic 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 InputStreamn - the number of bytes to be skipped.