InputStreamProgressMonitor.java

/*
 *    InputStreamProgressMonitor.java
 *    Copyright (C) 2007 University of Waikato, Hamilton, New Zealand
 *    @author Richard Kirkby (rkirkby@cs.waikato.ac.nz)
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package tr.gov.ulakbim.jDenetX.core;

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;

public class InputStreamProgressMonitor extends FilterInputStream {

    /**
     * The number of bytes to read in total
     */
    protected int inputByteSize;

    /**
     * The number of bytes read so far
     */
    protected int inputBytesRead;

    public InputStreamProgressMonitor(InputStream in) {
        super(in);
        try {
            this.inputByteSize = in.available();
        } catch (IOException ioe) {
            this.inputByteSize = 0;
        }
        this.inputBytesRead = 0;
    }

    public int getBytesRead() {
        return this.inputBytesRead;
    }

    public int getBytesRemaining() {
        return this.inputByteSize - this.inputBytesRead;
    }

    public double getProgressFraction() {
        return ((double) this.inputBytesRead / (double) this.inputByteSize);
    }

    /*
      * (non-Javadoc)
      *
      * @see java.io.InputStream#read()
      */

    @Override
    public int read() throws IOException {
        int c = this.in.read();
        if (c > 0) {
            this.inputBytesRead++;
        }
        return c;
    }

    /*
      * (non-Javadoc)
      * 
      * @see java.io.InputStream#read(byte[])
      */

    @Override
    public int read(byte[] b) throws IOException {
        int numread = this.in.read(b);
        if (numread > 0) {
            this.inputBytesRead += numread;
        }
        return numread;
    }

    /*
      * (non-Javadoc)
      * 
      * @see java.io.InputStream#read(byte[], int, int)
      */

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        int numread = this.in.read(b, off, len);
        if (numread > 0) {
            this.inputBytesRead += numread;
        }
        return numread;
    }

    /*
      * (non-Javadoc)
      * 
      * @see java.io.InputStream#skip(long)
      */

    @Override
    public long skip(long n) throws IOException {
        long numskip = this.in.skip(n);
        if (numskip > 0) {
            this.inputBytesRead += numskip;
        }
        return numskip;
    }

    /*
      * (non-Javadoc)
      * 
      * @see java.io.FilterInputStream#reset()
      */

    @Override
    public synchronized void reset() throws IOException {
        this.in.reset();
        this.inputBytesRead = this.inputByteSize - this.in.available();
    }

}