| java.lang.Object
 java.io.InputStream
java.io.FilterInputStream
All known Subclasses: sun.net.TelnetInputStream, sun.net.www.MeteredStream, java.io.BufferedInputStream, java.util.zip.InflaterInputStream, sun.audio.AudioStream, java.security.DigestInputStream, java.util.zip.CheckedInputStream, sun.audio.NativeAudioStream, java.io.PushbackInputStream,
| FilterInputStream | | public class FilterInputStream extends InputStream (Code) | | A FilterInputStream contains
some other input stream, which it uses as
its basic source of data, possibly transforming
the data along the way or providing additional
functionality. The class FilterInputStream
itself simply overrides all methods of
InputStream with versions that
pass all requests to the contained input
stream. Subclasses of FilterInputStream
may further override some of these methods
and may also provide additional methods
and fields.
author:
Jonathan Payne
version:
1.23, 02/02/00
since:
JDK1.0 |
| Field Summary | |
| protected InputStream | in
The input stream to be filtered. |
| Constructor Summary | |
| protected | FilterInputStream(InputStream in)
Creates a FilterInputStream
by assigning the argument in
to the field this.in so as
to remember it for later use. |
| Method Summary | |
| public int | available()
Returns the number of bytes that can be read from this input
stream without blocking. | | public void | close()
Closes this input stream and releases any system resources
associated with the stream. | | public synchronized void | mark(int readlimit)
Marks the current position in this input stream. | | public boolean | markSupported()
Tests if this input stream supports the mark
and reset methods. | | public int | read()
Reads the next byte of data from this input stream. | | public int | read(byte b)
Reads up to byte.length bytes of data from this
input stream into an array of bytes. | | 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. | | public synchronized void | reset()
Repositions this stream to the position at the time the
mark method was last called on this input stream. | | public long | skip(long n)
Skips over and discards n bytes of data from the
input stream. |
| FilterInputStream | | protected FilterInputStream(InputStream in)(Code) | | Creates a FilterInputStream
by assigning the argument in
to the field this.in so as
to remember it for later use.
Parameters:
in - the underlying input stream, or null if this instance is to be created without an underlying stream. |
| available | | public int available() throws IOException(Code) | | Returns the number of bytes that can be read from this input
stream without blocking.
This method
simply performs in.available() and
returns the result.
the number of bytes that can be read from the input streamwithout blocking.
exception:
IOException - if an I/O error occurs.
See Also: java.io.FilterInputStream.in |
| mark | | public synchronized void mark(int readlimit)(Code) | | Marks the current position in this input stream. A subsequent
call to the reset method repositions this stream at
the last marked position so that subsequent reads re-read the same bytes.
The readlimit argument tells this input stream to
allow that many bytes to be read before the mark position gets
invalidated.
This method simply performs in.mark(readlimit).
Parameters:
readlimit - the maximum limit of bytes that can be read beforethe mark position becomes invalid.
See Also: java.io.FilterInputStream.in
See Also: java.io.FilterInputStream.reset |
| read | | public int read() throws IOException(Code) | | 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 method blocks until input data
is available, the end of the stream is detected, or an exception
is thrown.
This method
simply performs in.read() and returns the result.
the next byte of data, or -1 if the end of thestream is reached.
exception:
IOException - if an I/O error occurs.
See Also: java.io.FilterInputStream.in |
| read | | public int read(byte b) throws IOException(Code) | | Reads up to byte.length bytes of data from this
input stream into an array of bytes. This method blocks until some
input is available.
This method simply performs the call
read(b, 0, b.length) and returns
the result. It is important that it does
not do in.read(b) instead;
certain subclasses of FilterInputStream
depend on the implementation strategy actually
used.
Parameters:
b - the buffer into which the data is 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:
IOException - if an I/O error occurs.
See Also: java.io.FilterInputStream.read(byte[]intint) |
| read | | public int read(byte b, int off, int len) throws IOException(Code) | | Reads up to len bytes of data from this input stream
into an array of bytes. This method blocks until some input is
available.
This method simply performs in.read(b, off, len)
and returns the result.
Parameters:
b - the buffer into which the data is read.
Parameters:
off - the start offset of the data.
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:
IOException - if an I/O error occurs.
See Also: java.io.FilterInputStream.in |
| reset | | public synchronized void reset() throws IOException(Code) | | Repositions this stream to the position at the time the
mark method was last called on this input stream.
This method
simply performs in.reset().
Stream marks are intended to be used in
situations where you need to read ahead a little to see what's in
the stream. Often this is most easily done by invoking some
general parser. If the stream is of the type handled by the
parse, it just chugs along happily. If the stream is not of
that type, the parser should toss an exception when it fails.
If this happens within readlimit bytes, it allows the outer
code to reset the stream and try another parser.
exception:
IOException - if the stream has not been marked or if themark has been invalidated.
See Also: java.io.FilterInputStream.in
See Also: java.io.FilterInputStream.mark(int) |
| skip | | public long skip(long n) throws IOException(Code) | | Skips over and discards n bytes of data from the
input stream. The skip method may, for a variety of
reasons, end up skipping over some smaller number of bytes,
possibly 0. The actual number of bytes skipped is
returned.
This method
simply performs in.skip(n).
Parameters:
n - the number of bytes to be skipped. the actual number of bytes skipped.
exception:
IOException - if an I/O error occurs. |
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