public class ChunkedInputStream extends InputStream
Constructor and Description |
---|
ChunkedInputStream(DataInputStream in) |
Modifier and Type | Method and Description |
---|---|
int |
available()
Returns an estimate of the number of bytes that can be read (or skipped over) from this input
stream without blocking by the next invocation of a method for this input stream.
|
void |
close()
Closes this input stream and releases any system resources associated with the stream.
|
int |
read()
Reads the next byte of data from the input stream.
|
int |
read(byte[] b,
int off,
int len)
Reads up to
len bytes of data from the input stream into an array of bytes. |
long |
skip(long n)
Skips over and discards
n bytes of data from this input stream. |
mark, markSupported, read, reset
public ChunkedInputStream(DataInputStream in)
in
- public int available() throws IOException
InputStream
Note that while some implementations of InputStream
will return the total number of bytes
in the stream, many will not. It is never correct to use the return value of this method to
allocate a buffer intended to hold all data in this stream.
A subclass' implementation of this method may choose to throw an IOException
if this
input stream has been closed by invoking the InputStream.close()
method.
The available
method for class InputStream
always returns 0
.
This method should be overridden by subclasses.
available
in class InputStream
0
when it reaches the end of the input stream.IOException
- if an I/O error occurs.public void close() throws IOException
InputStream
The close
method of InputStream
does nothing.
close
in interface Closeable
close
in interface AutoCloseable
close
in class InputStream
IOException
- if an I/O error occurs.public int read() throws IOException
InputStream
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 method blocks
until input data is available, the end of the stream is detected, or an exception is thrown.
A subclass must provide an implementation of this method.
read
in class InputStream
-1
if the end of the stream is reached.IOException
- if an I/O error occurs.public int read(byte[] b, int off, int len) throws IOException
InputStream
len
bytes of data from the input stream into an array of bytes. An
attempt is made to read as many as len
bytes, but a smaller number may be read. The
number of bytes actually read is returned as an integer.
This method blocks until input data is available, end of file is detected, or an exception is thrown.
If len
is zero, then no bytes are read and 0
is returned; otherwise,
there is an attempt to read at least one byte. If no byte is available because the stream is at
end of file, the value -1
is returned; otherwise, at least one byte is read and
stored into b
.
The first byte read is stored into element b[off]
, the next one into
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.
In every case, elements b[0]
through b[off]
and elements
b[off+len]
through b[b.length-1]
are unaffected.
The read(b,
off,
len)
method for class
InputStream
simply calls the method read()
repeatedly. If the first
such call results in an IOException
, that exception is returned from the call to the
read(b,
off,
len)
method. If any subsequent call to
read()
results in a IOException
, the exception is caught and treated as
if it were end of file; the bytes read up to that point are stored into b
and the
number of bytes read before the exception occurred is returned. The default implementation of
this method blocks until the requested amount of input data len
has been read, end
of file is detected, or an exception is thrown. Subclasses are encouraged to provide a more
efficient implementation of this method.
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.IOException
- If the first byte cannot be read for any reason other than end of file, or if the
input stream has been closed, or if some other I/O error occurs.InputStream.read()
public long skip(long n) throws IOException
InputStream
n
bytes of data from this input stream. The
skip
method may, for a variety of reasons, end up skipping over some smaller number
of bytes, possibly 0
. This may result from any of a number of conditions; reaching
end of file before n
bytes have been skipped is only one possibility. The actual
number of bytes skipped is returned. If n
is negative, no bytes are skipped.
The skip
method of this class creates a byte array and then repeatedly reads into it
until n
bytes have been read or the end of the stream has been reached. Subclasses
are encouraged to provide a more efficient implementation of this method. For instance, the
implementation may depend on the ability to seek.
skip
in class InputStream
n
- the number of bytes to be skipped.IOException
- if the stream does not support seek, or if some other I/O error occurs.