public class ProgressInputStream extends FilterInputStream
in
Constructor and Description |
---|
ProgressInputStream(InputStream in,
int totalBytes,
IProgressMonitor monitor)
Creates a progress input stream with a listener specifying the total number of bytes to read.
|
Modifier and Type | Method and Description |
---|---|
void |
mark(int readlimit)
Marks the current position in this input stream.
|
boolean |
markSupported()
Tests if this input stream supports the
mark and reset methods. |
int |
read()
Reads the next byte of data from this input stream.
|
int |
read(byte[] b,
int off,
int len)
Reads up to
len bytes of data from this input stream into an array of bytes. |
void |
reset()
Repositions this stream to the position at the time the
mark method was last called
on this input stream. |
long |
skip(long n)
Skips over and discards
n bytes of data from the input stream. |
available, close, read
public ProgressInputStream(InputStream in, int totalBytes, IProgressMonitor monitor)
in
- the underlying input stream.monitor
- the listener to notify or null
.totalBytes
- the total number of bytes to be read.public void mark(int readlimit)
FilterInputStream
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)
.
mark
in class FilterInputStream
readlimit
- the maximum limit of bytes that can be read before the mark position becomes invalid.FilterInputStream.in
,
FilterInputStream.reset()
public boolean markSupported()
FilterInputStream
mark
and reset
methods. This
method simply performs in.markSupported()
.markSupported
in class FilterInputStream
true
if this stream type supports the mark
and
reset
method; false
otherwise.FilterInputStream.in
,
InputStream.mark(int)
,
InputStream.reset()
public int read() throws IOException
FilterInputStream
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.
read
in class FilterInputStream
-1
if the end of the stream is reached.IOException
- if an I/O error occurs.FilterInputStream.in
public int read(byte[] b, int off, int len) throws IOException
FilterInputStream
len
bytes of data from this input stream into an array of bytes. If
len
is not zero, the method blocks until some input is available; otherwise, no
bytes are read and 0
is returned.
This method simply performs in.read(b, off, len)
and returns the result.
read
in class FilterInputStream
b
- the buffer into which the data is read.off
- the start offset in the destination array b
len
- the maximum number of bytes read.-1
if there is no more
data because the end of the stream has been reached.IOException
- if an I/O error occurs.FilterInputStream.in
public void reset() throws IOException
FilterInputStream
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.
reset
in class FilterInputStream
IOException
- if the stream has not been marked or if the mark has been invalidated.FilterInputStream.in
,
FilterInputStream.mark(int)
public long skip(long n) throws IOException
FilterInputStream
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)
.
skip
in class FilterInputStream
n
- the number of bytes to be skipped.IOException
- if the stream does not support seek, or if some other I/O error occurs.