package de.yaams.core.helper;
import java.io.File;
import java.io.InputStream;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Observable;
import de.yaams.core.helper.gui.YProgressWindowRepeat;
// 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
private int size; // size of download in bytes
private int downloaded; // number of bytes downloaded
private int status; // current status of download
private boolean viewMonitor;
private File dest;
// Constructor for Download.
public Download(URL url, File dest, boolean viewMonitor) {
this.url = url;
this.viewMonitor = viewMonitor;
this.dest = dest;
size = -1;
downloaded = 0;
status = DOWNLOADING;
// 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();
run();
}
// Download file.
@Override
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(dest, "rw");
file.seek(downloaded);
final YProgressWindowRepeat p = new YProgressWindowRepeat(I18N.t("Download {0} ({1})", url.toString(),
FileHelper.humanReadableByteCount(size, false)), "web");
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;
if (viewMonitor) {
p.setNote((I18N.t("{0}% / {1}", Math.round(getProgress()), FileHelper.humanReadableByteCount(downloaded, false))));
}
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();
}
}