THE PACKAGE JAVA.IO

java.io.LineNumberInputStream

22.12

22.12 The Class

java.io.LineNumberInputStream

A

LineNumberInputStream

 adds functionality to another input stream, namely

the ability to count lines. When the

LineNumberInputStream

 is created, the line

number counter is set to zero. As bytes from the stream are read or skipped, the

counter is incremented whenever a line terminator (

\n

,

\r

, or

\r\n

) is encoun 

tered. Such line terminators are also converted to a single

 \n 

 character. The

method

getLineNumber

 returns the current value of the counter, and the method

setLineNumber

 sets the counter to a given integer value. If the contained input

stream supports the

mark

 operation, then so does the

LineNumberInputStream

;

the

mark

 operation remembers the line number counter and the

reset

 operation

sets the counter to the value remembered by the

mark

 operation.

public class LineNumberInputStream extends FilterInputStream {

public LineNumberInputStream(InputStream in);

public int read() throws IOException;

public int read(byte[] b)

throws IOException, NullPointerException;

public int read(byte[] b, int off, int len)

throws IOException, NullPointerException,

IndexOutOfBoundsException;

public long skip(long n) throws IOException;

public int available() throws IOException;

public void mark(int readlimit);

public void reset() throws IOException;

public int getLineNumber();

public void setLineNumber(int lineNumber);

}

22.12.1

public LineNumberInputStream(InputStream in)

This constructor initializes a newly created

LineNumberInputStream

 by saving

its argument, the input stream

in

, for later use.

22.12.2

public int read() throws IOException

See the general contract of the

read

 method of

InputStream

 ( 22.3.1).

As bytes are read from the contained input stream, line terminators are recog 

nized and counted. For each line terminator recognized in the contained input

stream, a single character

 \n 

 is returned.

Overrides the

read

 method of

FilterInputStream

 ( 22.9.3).

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