Closeable
, AutoCloseable
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 | 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 byte in the input stream buffer. |
protected int |
mark |
The currently marked position in the stream. |
protected int |
pos |
The index of the next byte to read from the input stream buffer. |
Constructor | Description |
---|---|
ByteArrayInputStream |
Creates a ByteArrayInputStream so that it uses buf as its buffer array. |
ByteArrayInputStream |
Creates ByteArrayInputStream that uses buf as its buffer array. |
Modifier and Type | Method | 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 |
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 |
Reads up to len bytes of data into an array of bytes from this input stream. |
byte[] |
readAllBytes() |
Reads all remaining bytes from the input stream. |
int |
readNBytes |
Reads the requested number of bytes from the input stream into the given byte array. |
void |
reset() |
Resets the buffer to the marked position. |
long |
skip |
Skips n bytes of input from this input stream. |
nullInputStream, read, readNBytes, skipNBytes, transferTo
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 is 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. Unlike the overridden method
of InputStream
, this method returns -1
instead of zero if the end of the stream has been reached and len == 0
.
This read
method cannot block.
read
in class InputStream
b
- the buffer into which the data is read.off
- the start offset in array b
at which the data is written.len
- the maximum number of bytes to 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
public byte[] readAllBytes()
InputStream
When this stream reaches end of stream, further invocations of this method will return an empty byte array.
Note that this method is intended for simple cases where it is convenient to read all bytes into a byte array. It is not intended for reading input streams with large amounts of data.
The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified.
If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.
readAllBytes
in class InputStream
public int readNBytes(byte[] b, int off, int len)
InputStream
len
bytes of input data have been read, end of stream is detected, or an exception is thrown. The number of bytes actually read, possibly zero, is returned. This method does not close the input stream. In the case where end of stream is reached before len
bytes have been read, then the actual number of bytes read will be returned. When this stream reaches end of stream, further invocations of this method will return zero.
If len
is zero, then no bytes are read and 0
is returned; otherwise, there is an attempt to read up to len
bytes.
The first byte read is stored into element b[off]
, the next one in to b[off+1]
, and so on. The number of bytes read is, at most, equal to len
. Let k be the number of bytes actually read; these bytes will be stored in elements b[off]
through b[off+
k-1]
, leaving elements b[off+
k ]
through b[off+len-1]
unaffected.
The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified.
If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes of b
have been updated with data from the input stream. Consequently the input stream and b
may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.
readNBytes
in class InputStream
b
- the byte array into which the data is readoff
- the start offset in b
at which the data is writtenlen
- the maximum number of bytes to readpublic 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.markSupported
in class InputStream
markSupported
method of ByteArrayInputStream
always returns true
.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.public void reset()
reset
in class InputStream
public void close() throws IOException
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 AutoCloseable
close
in interface Closeable
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.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/io/ByteArrayInputStream.html