java.lang.Object | |||
↳ | java.io.InputStream | ||
↳ | java.io.FilterInputStream | ||
↳ | java.io.LineNumberInputStream |
This class is deprecated.
Use LineNumberReader
Wraps an existing InputStream
and counts the line terminators
encountered while reading the data. Line numbering starts at 0. Recognized
line terminator sequences are '\r'
, '\n'
and "\r\n"
.
When using read
, line terminator sequences are always translated into
'\n'
.
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Inherited Fields | |||||||||||
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From class
java.io.FilterInputStream
|
Public Constructors | |||||||||||
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Public Methods | |||||||||||
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Returns an estimated number of bytes that can be read or skipped without blocking for more
input.
Note that the source stream may just be a sequence of | |||||||||||
Returns the current line number for this stream.
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Sets a mark position in this stream.
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Reads a single byte from the filtered stream and returns it as an integer
in the range from 0 to 255.
| |||||||||||
Reads at most
length bytes from the filtered stream and stores
them in the byte array buffer starting at offset . | |||||||||||
Resets this stream to the last marked location.
| |||||||||||
Sets the line number of this stream to the specified
lineNumber . | |||||||||||
Skips
count number of bytes in this stream. |
[Expand]
Inherited Methods | |||||||||||
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From class java.io.FilterInputStream
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From class java.io.InputStream
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From class java.lang.Object
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From interface java.io.Closeable
|
Constructs a new LineNumberInputStream
on the InputStream
in
. Line numbers are counted for all data read from this stream.
Warning: passing a null source creates an invalid
LineNumberInputStream
. All operations on such a stream will fail.
in | The non-null input stream to count line numbers. |
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Returns an estimated number of bytes that can be read or skipped without blocking for more input.
Note that this method provides such a weak guarantee that it is not very useful in practice.
Firstly, the guarantee is "without blocking for more input" rather than "without blocking": a read may still block waiting for I/O to complete — the guarantee is merely that it won't have to wait indefinitely for data to be written. The result of this method should not be used as a license to do I/O on a thread that shouldn't be blocked.
Secondly, the result is a conservative estimate and may be significantly smaller than the actual number of bytes available. In particular, an implementation that always returns 0 would be correct. In general, callers should only use this method if they'd be satisfied with treating the result as a boolean yes or no answer to the question "is there definitely data ready?".
Thirdly, the fact that a given number of bytes is "available" does not guarantee that a read or skip will actually read or skip that many bytes: they may read or skip fewer.
It is particularly important to realize that you must not use this method to
size a container and assume that you can read the entirety of the stream without needing
to resize the container. Such callers should probably write everything they read to a
ByteArrayOutputStream
and convert that to a byte array. Alternatively, if you're
reading from a file, length()
returns the current length of the file (though
assuming the file's length can't change may be incorrect, reading a file is inherently
racy).
The default implementation of this method in InputStream
always returns 0.
Subclasses should override this method if they are able to indicate the number of bytes
available.
Note that the source stream may just be a sequence of "\r\n"
bytes
which are converted into '\n'
by this stream. Therefore,
available
returns only in.available() / 2
bytes as
result.
IOException |
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Returns the current line number for this stream. Numbering starts at 0.
Sets a mark position in this stream. The parameter readlimit
indicates how many bytes can be read before the mark is invalidated.
Sending reset()
will reposition this stream back to the marked
position, provided that readlimit
has not been surpassed.
The line number count will also be reset to the last marked
line number count.
This implementation sets a mark in the filtered stream.
readlimit | the number of bytes that can be read from this stream before the mark is invalidated. |
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Reads a single byte from the filtered stream and returns it as an integer in the range from 0 to 255. Returns -1 if the end of this stream has been reached.
The line number count is incremented if a line terminator is encountered.
Recognized line terminator sequences are '\r'
, '\n'
and
"\r\n"
. Line terminator sequences are always translated into
'\n'
.
IOException | if the stream is closed or another IOException occurs. |
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Reads at most length
bytes from the filtered stream and stores
them in the byte array buffer
starting at offset
.
Returns the number of bytes actually read or -1 if no bytes have been
read and the end of this stream has been reached.
The line number count is incremented if a line terminator is encountered.
Recognized line terminator sequences are '\r'
, '\n'
and
"\r\n"
. Line terminator sequences are always translated into
'\n'
.
buffer | the array in which to store the bytes read. |
---|---|
offset | the initial position in buffer to store the bytes read
from this stream. |
length | the maximum number of bytes to store in buffer . |
IndexOutOfBoundsException | if offset < 0 or length < 0 , or if
offset + length is greater than the length of
buffer . |
---|---|
IOException | if this stream is closed or another IOException occurs. |
NullPointerException | if buffer is null .
|
Resets this stream to the last marked location. It also resets the line count to what is was when this stream was marked.
IOException | if this stream is already closed, no mark has been set or the
mark is no longer valid because more than readlimit
bytes have been read since setting the mark. |
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Skips count
number of bytes in this stream. Subsequent
read()
's will not return these bytes unless reset()
is
used. This implementation skips count
number of bytes in the
filtered stream and increments the line number count whenever line
terminator sequences are skipped.
count | the number of bytes to skip. |
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IOException | if this stream is closed or another IOException occurs. |
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