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.
author: Arthur van Hoff version: 1.53, 05/05/07 See Also:java.io.StringBufferInputStream since: JDK1.0
Field Summary
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.
ByteArrayInputStream objects are marked at position zero by
default when constructed.
protected int
pos The index of the next character to read from the input stream buffer.
Constructor Summary
public
ByteArrayInputStream(byte buf) Creates a ByteArrayInputStream
so that it uses buf as its
buffer array.
public
ByteArrayInputStream(byte buf, int offset, int length) Creates ByteArrayInputStream
that uses buf as its
buffer array.
Method Summary
public synchronized int
available() Returns the number of remaining bytes that can be read (or skipped over)
from this input stream.
public void
close() Closing a ByteArrayInputStream has no effect.
public void
mark(int readAheadLimit) Set the current marked position in the stream.
ByteArrayInputStream objects are marked at position zero by
default when constructed.
public boolean
markSupported() Tests if this InputStream supports mark/reset.
public synchronized int
read() Reads the next byte of data from this input stream.
public synchronized int
read(byte b, int off, int len) Reads up to len bytes of data into an array of bytes
from this input stream.
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.
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.
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).
since: JDK1.1
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].
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.
Parameters: buf - the input buffer.
ByteArrayInputStream
public ByteArrayInputStream(byte buf, int offset, int length)(Code)
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.
Parameters: buf - the input buffer. Parameters: offset - the offset in the buffer of the first byte to read. Parameters: length - the maximum number of bytes to read from the buffer.
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.
the number of remaining bytes that can be read (or skippedover) from this input stream without blocking.
Closing a ByteArrayInputStream has no effect. The methods in
this class can be called after the stream has been closed without
generating an IOException.
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.
since: JDK1.1
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.
the next byte of data, or -1 if the end of thestream has been reached.
read
public synchronized int read(byte b, int off, int len)(Code)
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.
Parameters: b - the buffer into which the data is read. Parameters: off - the start offset in the destination array b Parameters: len - the maximum number of bytes read. the total number of bytes read into the buffer, or-1 if there is no more data because the end ofthe stream has been reached. exception: NullPointerException - If b is null. exception: IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off
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.
Parameters: n - the number of bytes to be skipped. the actual number of bytes skipped.
