Class LineNumberInputStream
- java.lang.Object
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- java.io.InputStream
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- java.io.FilterInputStream
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- java.io.LineNumberInputStream
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- All Implemented Interfaces:
- Closeable, AutoCloseable
Deprecated.This class incorrectly assumes that bytes adequately represent characters. As of JDK 1.1, the preferred way to operate on character streams is via the new character-stream classes, which include a class for counting line numbers.
@Deprecated public class LineNumberInputStream extends FilterInputStream
This class is an input stream filter that provides the added functionality of keeping track of the current line number.A line is a sequence of bytes ending with a carriage return character (
'\r'
), a newline character ('\n'
), or a carriage return character followed immediately by a linefeed character. In all three cases, the line terminating character(s) are returned as a single newline character.The line number begins at
0
, and is incremented by1
when aread
returns a newline character.- Since:
- JDK1.0
- See Also:
-
LineNumberReader
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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 and Description LineNumberInputStream(InputStream in)
Deprecated.Constructs a newline number input stream that reads its input from the specified input stream.
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Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method and Description int
available()
Deprecated.Returns the number of bytes that can be read from this input stream without blocking.int
getLineNumber()
Deprecated.Returns the current line number.void
mark(int readlimit)
Deprecated.Marks the current position in this input stream.int
read()
Deprecated.Reads the next byte of data from this input stream.int
read(byte[] b, int off, int len)
Deprecated.Reads up tolen
bytes of data from this input stream into an array of bytes.void
reset()
Deprecated.Repositions this stream to the position at the time themark
method was last called on this input stream.void
setLineNumber(int lineNumber)
Deprecated.Sets the line number to the specified argument.long
skip(long n)
Deprecated.Skips over and discardsn
bytes of data from this input stream.-
Methods inherited from class java.io.FilterInputStream
close, markSupported, read
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Constructor Detail
LineNumberInputStream
public LineNumberInputStream(InputStream in)
Deprecated.Constructs a newline number input stream that reads its input from the specified input stream.- Parameters:
-
in
- the underlying input stream.
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Method Detail
read
public int read() throws IOException
Deprecated.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.The
read
method ofLineNumberInputStream
calls theread
method of the underlying input stream. It checks for carriage returns and newline characters in the input, and modifies the current line number as appropriate. A carriage-return character or a carriage return followed by a newline character are both converted into a single newline character.- Overrides:
-
read
in classFilterInputStream
- Returns:
-
the next byte of data, or
-1
if the end of this stream is reached. - Throws:
-
IOException
- if an I/O error occurs. - See Also:
-
FilterInputStream.in
,getLineNumber()
read
public int read(byte[] b, int off, int len) throws IOException
Deprecated.Reads up tolen
bytes of data from this input stream into an array of bytes. This method blocks until some input is available.The
read
method ofLineNumberInputStream
repeatedly calls theread
method of zero arguments to fill in the byte array.- Overrides:
-
read
in classFilterInputStream
- Parameters:
-
b
- the buffer into which the data is read. -
off
- the start offset of the data. -
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 this stream has been reached. - Throws:
-
IOException
- if an I/O error occurs. - See Also:
-
read()
skip
public long skip(long n) throws IOException
Deprecated.Skips over and discardsn
bytes of data from this 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. Ifn
is negative, no bytes are skipped.The
skip
method ofLineNumberInputStream
creates a byte array and then repeatedly reads into it untiln
bytes have been read or the end of the stream has been reached.- Overrides:
-
skip
in classFilterInputStream
- Parameters:
-
n
- the number of bytes to be skipped. - Returns:
- the actual number of bytes skipped.
- Throws:
-
IOException
- if an I/O error occurs. - See Also:
-
FilterInputStream.in
setLineNumber
public void setLineNumber(int lineNumber)
Deprecated.Sets the line number to the specified argument.- Parameters:
-
lineNumber
- the new line number. - See Also:
-
getLineNumber()
getLineNumber
public int getLineNumber()
Deprecated.Returns the current line number.- Returns:
- the current line number.
- See Also:
-
setLineNumber(int)
available
public int available() throws IOException
Deprecated.Returns the number of bytes that can be read from this input stream without blocking.Note that if the underlying input stream is able to supply k input characters without blocking, the
LineNumberInputStream
can guarantee only to provide k/2 characters without blocking, because the k characters from the underlying input stream might consist of k/2 pairs of'\r'
and'\n'
, which are converted to just k/2'\n'
characters.- Overrides:
-
available
in classFilterInputStream
- Returns:
- the number of bytes that can be read from this input stream without blocking.
- Throws:
-
IOException
- if an I/O error occurs. - See Also:
-
FilterInputStream.in
mark
public void mark(int readlimit)
Deprecated.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
mark
method ofLineNumberInputStream
remembers the current line number in a private variable, and then calls themark
method of the underlying input stream.- 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
,reset()
reset
public void reset() throws IOException
Deprecated.Repositions this stream to the position at the time themark
method was last called on this input stream.The
reset
method ofLineNumberInputStream
resets the line number to be the line number at the time themark
method was called, and then calls thereset
method of the underlying input stream.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 parser, it just chugs along happily. If the stream is not of that type, the parser should toss an exception when it fails, which, if it happens within readlimit bytes, allows the outer code to reset the stream and try another parser.
- Overrides:
-
reset
in classFilterInputStream
- Throws:
-
IOException
- if an I/O error occurs. - See Also:
-
FilterInputStream.in
,mark(int)
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