/*######################################################################
#
# Project: DLApplet
# URL: http://www.nabber.org/projects/
# E-mail: webmaster@nabber.org
#
# Copyright: (C) 2009, Neil McNab
# License: GNU General Public License Version 2
# (http://www.gnu.org/copyleft/gpl.html)
#
# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# Filename: $URL$
# Last Updated: $Date$
# Author(s): Neil McNab
#
# Description:
# Class to handle normal downloads. Tries alternate URLs if failure.
######################################################################*/
// FROM: http://www.java-tips.org/java-se-tips/javax.swing/how-to-create-a-download-manager-in-java.html
import java.io.*;
import java.net.*;
import java.util.*;
// This class downloads a file from a URL.
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
ArrayList <String> urls = new ArrayList <String> ();
private String filename;
private String path;
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(MetalinkFile ml, String pathin) {
filename = ml.filename;
path = pathin;
urls = ml.get_urls();
size = -1;
downloaded = 0;
status = DOWNLOADING;
// Begin the download.
download();
}
/*public void setUrl(URL url) {
this.url = url;
}*/
/*public void setPath(String path) {
this.download_path = path;
}*/
// 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();
}
public String displayFileName() {
return filename;
}
public String getFileName() {
return path;// + "/" + filename;
}
// Download file.
public void run() {
RandomAccessFile file = null;
InputStream stream = null;
URL url = null;
for (String urlstr : urls) {
if (status == ERROR) {
status = DOWNLOADING;
}
System.out.println("trying url normally: " + urlstr);
try {
url = new URL(urlstr);
} catch (MalformedURLException e) {
e.printStackTrace();
}
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(getFileName(), "rw");
//file = new RandomAccessFile(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) {}
}
}
if (status != ERROR) {
break;
}
}
}
// Notify observers that this download's status has changed.
private void stateChanged() {
setChanged();
notifyObservers();
}
}