SequenceInputStream
public
class
SequenceInputStream
extends InputStream
java.lang.Object | ||
↳ | java.io.InputStream | |
↳ | java.io.SequenceInputStream |
A SequenceInputStream
represents
the logical concatenation of other input
streams. It starts out with an ordered
collection of input streams and reads from
the first one until end of file is reached,
whereupon it reads from the second one,
and so on, until end of file is reached
on the last of the contained input streams.
Summary
Public constructors | |
---|---|
SequenceInputStream(Enumeration<? extends InputStream> e)
Initializes a newly created |
|
SequenceInputStream(InputStream s1, InputStream s2)
Initializes a newly
created |
Public methods | |
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int
|
available()
Returns an estimate of the number of bytes that can be read (or skipped over) from the current underlying input stream without blocking by the next invocation of a method for the current underlying 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 this input stream. |
int
|
read(byte[] b, int off, int len)
Reads up to |
Inherited methods | |
---|---|
Public constructors
SequenceInputStream
public SequenceInputStream (Enumeration<? extends InputStream> e)
Initializes a newly created SequenceInputStream
by remembering the argument, which must
be an Enumeration
that produces
objects whose run-time type is InputStream
.
The input streams that are produced by
the enumeration will be read, in order,
to provide the bytes to be read from this
SequenceInputStream
. After
each input stream from the enumeration
is exhausted, it is closed by calling its
close
method.
Parameters | |
---|---|
e |
Enumeration : an enumeration of input streams. |
See also:
SequenceInputStream
public SequenceInputStream (InputStream s1, InputStream s2)
Initializes a newly
created SequenceInputStream
by remembering the two arguments, which
will be read in order, first s1
and then s2
, to provide the
bytes to be read from this SequenceInputStream
.
Parameters | |
---|---|
s1 |
InputStream : the first input stream to read. |
s2 |
InputStream : the second input stream to read. |
Public methods
available
public int available ()
Returns an estimate of the number of bytes that can be read (or skipped over) from the current underlying input stream without blocking by the next invocation of a method for the current underlying input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.
This method simply calls available
of the current underlying
input stream and returns the result.
Returns | |
---|---|
int |
an estimate of the number of bytes that can be read (or
skipped over) from the current underlying input stream
without blocking or 0 if this input stream
has been closed by invoking its close() method |
Throws | |
---|---|
IOException |
if an I/O error occurs. |
close
public void close ()
Closes this input stream and releases any system resources
associated with the stream.
A closed SequenceInputStream
cannot perform input operations and cannot
be reopened.
If this stream was created
from an enumeration, all remaining elements
are requested from the enumeration and closed
before the close
method returns.
Throws | |
---|---|
IOException |
if an I/O error occurs. |
read
public int read ()
Reads the next byte of data from this input stream. The 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 method blocks until input data is available, the end of the
stream is detected, or an exception is thrown.
This method
tries to read one character from the current substream. If it
reaches the end of the stream, it calls the close
method of the current substream and begins reading from the next
substream.
Returns | |
---|---|
int |
the next byte of data, or -1 if the end of the
stream is reached. |
Throws | |
---|---|
IOException |
if an I/O error occurs. |
read
public int read (byte[] b, int off, int len)
Reads up to len
bytes of data from this input stream
into an array of bytes. If len
is not zero, the method
blocks until at least 1 byte of input is available; otherwise, no
bytes are read and 0
is returned.
The read
method of SequenceInputStream
tries to read the data from the current substream. If it fails to
read any characters because the substream has reached the end of
the stream, it calls the close
method of the current
substream and begins reading from the next substream.
Parameters | |
---|---|
b |
byte : the buffer into which the data is read. |
off |
int : the start offset in array b
at which the data is written. |
len |
int : the maximum number of bytes read. |
Returns | |
---|---|
int |
int the number of bytes read. |
Throws | |
---|---|
NullPointerException |
If b is null . |
IndexOutOfBoundsException |
If off is negative,
len is negative, or len is greater than
b.length - off |
IOException |
if an I/O error occurs. |