Download.java

/**
 * KKMulticopterFlashTool, a avrdude GUI for flashing KK boards and other
 *   equipment.
 *   Copyright (C) 2011 Christian Moll
 *
 *   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 3 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, see <http://www.gnu.org/licenses/>.
 */
package de.lazyzero.kkMulticopterFlashTool.utils.download;

import java.io.InputStream;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Date;
import java.util.Observable;

import de.lazyzero.kkMulticopterFlashTool.KKMulticopterFlashTool;

// This class downloads a file from a URL.
public class Download extends Observable implements Runnable {
    
    // Max size of download buffer.
    private static final int MAX_BUFFER_SIZE = 1024;
    
    // These are the status names.
    public static final String STATUSES[] = {"Downloading",
    "Paused", "Complete", "Cancelled", "Error"};
    
    // These are the status codes.
    public static final int DOWNLOADING = 0;
    public static final int PAUSED = 1;
    public static final int COMPLETE = 2;
    public static final int CANCELLED = 3;
    public static final int ERROR = 4;
    
    private URL url; // download URL
    private String name; // the download name
    private int size; // size of download in bytes
    private int downloaded; // number of bytes downloaded
    private int status; // current status of download
    
    // Constructor for Download.
    public Download(URL url) {
        this.url = url;
        size = -1;
        downloaded = 0;
        status = DOWNLOADING;
        this.name = this.url.getFile();
        this.name = (String) this.name.subSequence(this.name.lastIndexOf("/")+1, this.name.length());
//        this.name = this.name.split("\\.")[0];
//        this.name = new String(this.name.charAt(0)+"").toUpperCase() + this.name.substring(1);
        // Begin the download.
        download();
    }
    
 // Constructor for Download.
    public Download(URL url, String name) {
        this.url = url;
        size = -1;
        downloaded = 0;
        status = DOWNLOADING;
        this.name = name;
        // Begin the download.
        download();
    }
    
    // Get this download's URL.
    public String getUrl() {
        return url.toString();
    }
    
    // Get this download's size.
    public int getSize() {
        return size;
    }
    
    // Get this download's progress.
    public float getProgress() {
        return ((float) downloaded / size) * 100;
    }
    
    // Get this download's status.
    public int getStatus() {
        return status;
    }
    
    // Pause this download.
    public void pause() {
        status = PAUSED;
        stateChanged();
    }
    
    // Resume this download.
    public void resume() {
        status = DOWNLOADING;
        stateChanged();
        download();
    }
    
    // Cancel this download.
    public void cancel() {
        status = CANCELLED;
        stateChanged();
    }
    
    // Mark this download as having an error.
    private void error() {
        status = ERROR;
        stateChanged();
    }
    
    // Start or resume downloading.
    private void download() {
        Thread thread = new Thread(this);
        thread.start();
    }
    
    // Get file name portion of URL.
    private String getFileName(URL url) {
        String fileName = url.getFile();
        return fileName.substring(fileName.lastIndexOf('/') + 1);
    }
    
    // Download file.
    public void run() {
        RandomAccessFile file = null;
        InputStream stream = null;
        
        try {
            // Open connection to URL.
            HttpURLConnection connection =
                    (HttpURLConnection) url.openConnection();
            
            // Specify what portion of file to download.
            connection.setRequestProperty("Range",
                    "bytes=" + downloaded + "-");
            
            // Connect to server.
            connection.connect();
            
            // Make sure response code is in the 200 range.
            if (connection.getResponseCode() / 100 != 2) {
                error();
            }
            
            // Check for valid content length.
            int contentLength = connection.getContentLength();
            if (contentLength < 1) {
                error();
            }
            
      /* Set the size for this download if it
         hasn't been already set. */
            if (size == -1) {
                size = contentLength;
                stateChanged();
            }
            
            // Open file and seek to the end of it.
            file = new RandomAccessFile(KKMulticopterFlashTool.getTempFolder() + getFileName(url), "rw");
            file.seek(downloaded);
            
            stream = connection.getInputStream();
            while (status == DOWNLOADING) {
        /* Size buffer according to how much of the
           file is left to download. */
                byte buffer[];
                if (size - downloaded > MAX_BUFFER_SIZE) {
                    buffer = new byte[MAX_BUFFER_SIZE];
                } else {
                    buffer = new byte[size - downloaded];
                }
                
                // Read from server into buffer.
                int read = stream.read(buffer);
                if (read == -1)
                    break;
                
                // Write buffer to file.
                file.write(buffer, 0, read);
                downloaded += read;
                stateChanged();
            }
            
      /* Change status to complete if this point was
         reached because downloading has finished. */
            if (status == DOWNLOADING) {
                status = COMPLETE;
                stateChanged();
            }
        } catch (Exception e) {
            error();
        } finally {
            // Close file.
            if (file != null) {
                try {
                    file.close();
                } catch (Exception e) {}
            }
            
            // Close connection to server.
            if (stream != null) {
                try {
                    stream.close();
                } catch (Exception e) {}
            }
        }
    }
    
    // Notify observers that this download's status has changed.
    private void stateChanged() {
        setChanged();
        notifyObservers();
    }

	public double getSpeed() {
		int d1 = new Integer(downloaded);
		Date t1 = new Date();
		while ((new Date()).getTime()-t1.getTime()<500){
			
		}
		int d2 = new Integer(downloaded);
		return (double)(d2-d1)/512;
	}

	public String getName() {
		return name;
	}
}