Class CountingInputStream
- java.lang.Object
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- java.io.InputStream
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- java.io.FilterInputStream
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- com.google.common.io.CountingInputStream
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- All Implemented Interfaces:
Closeable
,AutoCloseable
@Beta @GwtIncompatible public final class CountingInputStream extends FilterInputStream
AnInputStream
that counts the number of bytes read.- Since:
- 1.0
- Author:
- Chris Nokleberg
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Field Summary
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Fields inherited from class java.io.FilterInputStream
in
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Constructor Summary
Constructors Constructor Description CountingInputStream(InputStream in)
Wraps another input stream, counting the number of bytes read.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description long
getCount()
Returns the number of bytes read.void
mark(int readlimit)
Marks the current position in this input stream.int
read()
Reads the next byte of data from this input stream.int
read(byte[] b, int off, int len)
Reads up tolen
bytes of data from this input stream into an array of bytes.void
reset()
Repositions this stream to the position at the time themark
method was last called on this input stream.long
skip(long n)
Skips over and discardsn
bytes of data from the input stream.-
Methods inherited from class java.io.FilterInputStream
available, close, markSupported, read
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Methods inherited from class java.io.InputStream
nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo
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Constructor Detail
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CountingInputStream
public CountingInputStream(InputStream in)
Wraps another input stream, counting the number of bytes read.- Parameters:
in
- the input stream to be wrapped
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Method Detail
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getCount
public long getCount()
Returns the number of bytes read.
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read
public int read() throws IOException
Description copied from class:java.io.FilterInputStream
Reads the next byte of data from this input stream. The value byte is returned as anint
in the range0
to255
. 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.- Overrides:
read
in classFilterInputStream
- Returns:
- the next byte of data, or
-1
if the end of the stream is reached. - Throws:
IOException
- if an I/O error occurs.- See Also:
FilterInputStream.in
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read
public int read(byte[] b, int off, int len) throws IOException
Description copied from class:java.io.FilterInputStream
Reads up tolen
bytes of data from this input stream into an array of bytes. Iflen
is not zero, the method blocks until some input is available; otherwise, no bytes are read and0
is returned.This method simply performs
in.read(b, off, len)
and returns the result.- Overrides:
read
in classFilterInputStream
- Parameters:
b
- the buffer into which the data is read.off
- the start offset in the destination arrayb
len
- the maximum number of bytes read.- Returns:
- the total number of bytes read into the buffer, or
-1
if there is no more data because the end of the stream has been reached. - Throws:
IOException
- if an I/O error occurs.- See Also:
FilterInputStream.in
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skip
public long skip(long n) throws IOException
Description copied from class:java.io.FilterInputStream
Skips over and discardsn
bytes of data from the input stream. Theskip
method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly0
. The actual number of bytes skipped is returned.This method simply performs
in.skip(n)
.- Overrides:
skip
in classFilterInputStream
- Parameters:
n
- the number of bytes to be skipped.- Returns:
- the actual number of bytes skipped.
- Throws:
IOException
- ifin.skip(n)
throws an IOException.
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mark
public void mark(int readlimit)
Description copied from class:java.io.FilterInputStream
Marks the current position in this input stream. A subsequent call to thereset
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)
.- Overrides:
mark
in classFilterInputStream
- Parameters:
readlimit
- the maximum limit of bytes that can be read before the mark position becomes invalid.- See Also:
FilterInputStream.in
,FilterInputStream.reset()
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reset
public void reset() throws IOException
Description copied from class:java.io.FilterInputStream
Repositions this stream to the position at the time themark
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.
- Overrides:
reset
in classFilterInputStream
- Throws:
IOException
- if the stream has not been marked or if the mark has been invalidated.- See Also:
FilterInputStream.in
,FilterInputStream.mark(int)
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