Class LineNumberInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

java.io.LineNumberInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

@Deprecated
public class LineNumberInputStream
extends FilterInputStream

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.

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 by 1 when a read returns a newline character.

Since:

1.0

See Also:

• LineNumberReader

Field Summary

Fields declared in class FilterInputStream

in

Modifier and Type	Field	Description
protected InputStream	in	The input stream to be filtered.

Constructor Summary

Constructors

Constructor	Description
LineNumberInputStream(InputStream in)	Deprecated. Constructs a newline number input stream that reads its input from the specified input stream.

Method Summary

Modifier and Type	Method	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 to len bytes of data from this input stream into an array of bytes.
void	reset()	Deprecated. Repositions this stream to the position at the time the mark 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 discards n bytes of data from this input stream.

Methods declared in class FilterInputStream

close, markSupported, read

Modifier and Type	Method	Description
void	close()	Closes this input stream and releases any system resources associated with the stream.
boolean	markSupported()	Tests if this input stream supports the mark and reset methods.
int	read(byte[] b)	Reads up to b.length bytes of data from this input stream into an array of bytes.

Methods declared in class InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Modifier and Type	Method	Description
static InputStream	nullInputStream()	Returns a new InputStream that reads no bytes.
byte[]	readAllBytes()	Reads all remaining bytes from the input stream.
int	readNBytes(byte[] b, int off, int len)	Reads the requested number of bytes from the input stream into the given byte array.
byte[]	readNBytes(int len)	Reads up to a specified number of bytes from the input stream.
void	skipNBytes(long n)	Skips over and discards exactly n bytes of data from this input stream.
long	transferTo(OutputStream out)	Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Constructor Details

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.

Method Details

read

public int read()
         throws IOException

Deprecated.

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.

The read method of LineNumberInputStream calls the read 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 class FilterInputStream

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 to len bytes of data from this input stream into an array of bytes. This method blocks until some input is available.

The read method of LineNumberInputStream repeatedly calls the read method of zero arguments to fill in the byte array.

Overrides:

read in class FilterInputStream

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 discards n bytes of data from this 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. If n is negative, no bytes are skipped.

The skip method of LineNumberInputStream creates a byte array and then repeatedly reads into it until n bytes have been read or the end of the stream has been reached.

Overrides:

skip in class FilterInputStream

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 class FilterInputStream

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 the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

The mark method of LineNumberInputStream remembers the current line number in a private variable, and then calls the mark method of the underlying input stream.

Overrides:

mark in class FilterInputStream

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 the mark method was last called on this input stream.

The reset method of LineNumberInputStream resets the line number to be the line number at the time the mark method was called, and then calls the reset 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 class FilterInputStream

Throws:

IOException - if an I/O error occurs.

See Also:

• FilterInputStream.in
• mark(int)