org.unix4j.processor

Interface InputProcessor

All Known Implementing Classes:

CountMatchingLinesProcessor, DefaultInputProcessor, WcFileProcessor, WriteFilesWithMatchingLinesProcessor

public interface InputProcessor

An InputProcessor is used by a MultipleInputLineProcessor to process line based data from multiple Input devices. It is very similar to a LineProcessor but has an extra begin(..) method and input and output is passed to every method.

Method Summary

Methods

Modifier and Type	Method and Description
void	begin(Input input, LineProcessor output) Indicates that the line processing task is about to start for the specified input device.
void	finish(Input input, LineProcessor output) Indicates that this line processing task is complete for the specified input device and can finished.
boolean	processLine(Input input, Line line, LineProcessor output) Processes a single line and returns true if this InputProcessor is ready to process more lines.

Method Detail

begin

void begin(Input input,
         LineProcessor output)

Indicates that the line processing task is about to start for the specified input device.

Parameters:

input - the input device whose lines are about to be processed next

output - the output to write to

processLine

boolean processLine(Input input,
                  Line line,
                  LineProcessor output)

Processes a single line and returns true if this InputProcessor is ready to process more lines. Returning false indicates that the process can be finished because subsequent lines would not change the result anyway.

Parameters:

input - the input device, the source of the given line

line - the line to process

output - the output to write to

Returns:

true if this InputProcessor is ready to process more lines, and false if it does not require any more input lines

finish

void finish(Input input,
          LineProcessor output)

Indicates that this line processing task is complete for the specified input device and can finished.

Simple output devices usually perform a flush operation in this method. More complex commands may perform the real operation in this method, for instance write the total count of lines or words to the target file or stream.

Parameters:

input - the input device whose lines have now all been processed

output - the output to write to