SourceFilter.java

/******************************************************************************************************************
* File:SourceFilter.java
* Course: 17655
* Project: Assignment 1
* Copyright: Copyright (c) 2003 Carnegie Mellon University
* Versions:
*	1.0 November 2008 - Sample Pipe and Filter code (ajl).
*
* Description:
*
* This class serves as an example for how to use the SourceFilterTemplate to create a source filter. This particular
* filter is a source filter that reads some input from the FlightData.dat file and writes the bytes up stream.
*
* Parameters: 		None
*
* Internal Methods: None
*
******************************************************************************************************************/

import java.io.*; // note we must add this here since we use BufferedReader class to read from the keyboard

public class SourceFilter extends FilterFramework
{
	public static void main(String[] args)
	{
		PipedOutputStream outputWritePort[] = new PipedOutputStream[2];
		outputWritePort[0] = new PipedOutputStream();
		outputWritePort[1] = new PipedOutputStream();		
		SourceFilter source = new SourceFilter(null,outputWritePort, "/Users/nanchen/eclipseWorkspace/analysis/Sample1/src/sample/SubSetA.dat", null);
		source.run();
	}
	
	private String filepath;
	
	public SourceFilter(PipedInputStream inputReadPort[], PipedOutputStream outputWritePort[], 
			String path, int[] idToProcess)
	{
		super(inputReadPort, outputWritePort, idToProcess);
		filepath = path;
	}
	
	public void run()
    {

		String fileName = filepath;	// Input data file.
		int bytesread = 0;					// Number of bytes read from the input file.
		int byteswritten = 0;				// Number of bytes written to the stream.
		DataInputStream in = null;			// File stream reference.
		byte databyte = 0;					// The byte of data read from the file

		try
		{
			/***********************************************************************************
			*	Here we open the file and write a message to the terminal.
			***********************************************************************************/
			in = new DataInputStream(new FileInputStream(fileName));
			System.out.println("\n" + this.getName() + "::Source reading file..." );

			/***********************************************************************************
			*	Here we read the data from the file and send it out the filter's output port one
			* 	byte at a time. The loop stops when it encounters an EOFExecption.
			***********************************************************************************/
			while(true)
			{
				databyte = in.readByte();
				bytesread++;
				WriteFilterOutputPort(databyte,0);
				byteswritten++;
			} // while

		} //try

		/***********************************************************************************
		*	The following exception is raised when we hit the end of input file. Once we
		* 	reach this point, we close the input file, close the filter ports and exit.
		***********************************************************************************/

		catch ( EOFException eoferr )
		{
			System.out.println("\n\n" + this.getName() + "::End of file reached..." );
			try
			{
				in.close();
				ClosePorts();
				System.out.println( "\n" + this.getName() + "::Read file complete, bytes read::" + bytesread + " bytes written: " + byteswritten );
			}
		/***********************************************************************************
		*	The following exception is raised should we have a problem closing the file.
		***********************************************************************************/
			catch (Exception closeerr)
			{
				System.out.println("\n" + this.getName() + "::Problem closing input data file::" + closeerr);
			} // catch

		} // catch

		/***********************************************************************************
		*	The following exception is raised should we have a problem openinging the file.
		***********************************************************************************/

		catch ( IOException iox )
		{
			System.out.println("\n" + this.getName() + "::Problem reading input data file::" + iox );
		} // catch

   } // run

} // SourceFilter