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public  class  java.io.LineNumberInputStream
    extends  java.io.FilterInputStream  (I-§2.11)
{
        // Constructors
    public LineNumberInputStream(InputStream  in);	§2.14.1

        // Methods
    public int available();	§2.14.2
    public int getLineNumber();	§2.14.3
    public void mark(int  readlimit);	§2.14.4
    public int read();	§2.14.5
    public int read(byte  b[], int  off, int  len);	§2.14.6
    public void reset();	§2.14.7
    public void setLineNumber(int  lineNumber);	§2.14.8
    public long skip(long  n);	§2.14.9
}

A line is a sequence of bytes ending with either a carriage return character ('\r'), a newline character ('\n'), or a carriage return character followed immediately by a line feed character. In all three cases the line terminating character(s) are returned as a single newline character.

The line number begins at zero, and is incremented by 1 when a read returns a newline character.

Constructs a new line number input stream that reads its input from the specified input stream.

Parameters:

in - the underlying input stream

Determines the number of bytes that can be read from this input stream without blocking.

Note that if the underlying input stream (I-§2.11.1) is able to supply k input characters without blocking, the LineNumberInputStream can guarantee only to provide characters without blocking, because the k characters from the underlyhing input stream might consist of pairs of '\r' and '\n', which are converted to just '\n' characters.

Returns:

the number of bytes that can be read from this input stream without blocking.

Throws

IOException (I-§2.29)

If an I/O error occurs.

Overrides:

available in class FilterInputStream (I-§2.11.3).

Returns:

the current line number.

Marks the current position in this input stream. A subsequent call to the reset method (I-§2.14.7) 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 (I-§2.11.1).

Parameters:

readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.

Overrides:

mark in class FilterInputStream (I-§2.11.5).

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 either 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 (I-§2.11.1). It checks for carriage returns and newline characters in the input, and modifies the current line number (I-§2.14.3) as appropriate. A carriage return character or a carriage return followed by a newline character are both converted into a single newline character.

Returns:

the next byte of data, or -1 if the end of this stream is reached

Throws

IOException (I-§2.29)

If an I/O error occurs.

Overrides:

read in class FilterInputStream (I-§2.11.7).

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 (I-§2.14.5) to fill in the byte array.

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 is there is no more data because the end of this stream has been reached.

Throws

IOException (I-§2.29)

If an I/O error occurs.

Overrides:

read in class FilterInputStream (I-§2.11.9).

Repositions this stream to the position at the time the mark method (I-§2.14.4) 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 mark method of the underlying input stream (I-§2.11.1).

Throws

IOException (I-§2.29)

If an I/O error occurs.

Overrides:

reset in class FilterInputStream (I-§2.11.10).

Sets the line number to the specified argument.

Parameters:

lineNumber - the new line number

Skips over and discards n bytes of data from the input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly zero. The actual number of bytes skipped is returned.

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

Parameters:

n - the number of bytes to be skipped

Returns:

the actual number of bytes skipped.

Throws

IOException (I-§2.29)

If an I/O error occurs.

Overrides:

skip in class FilterInputStream (I-§2.11.11).

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