/**
* Starts the download component.
*
* @throws SmartFrogException in case of error in starting
* @throws RemoteException in case of network/emi error
*/
@Override
public synchronized void sfStart() throws SmartFrogException, RemoteException {
super.sfStart();
log = sfGetApplicationLog();
String url = "NOT YET SET";
String localFile = "NOT YET SET";
try {
url = (String) sfResolve(ATTR_URL);
localFile = FileSystem.lookupAbsolutePath(this, ATTR_LOCALFILE, null, null, true, null);
int blocksize = ((Integer) sfResolve(ATTR_BLOCKSIZE)).intValue();
int maxCacheAge = -1;
maxCacheAge = sfResolve(ATTR_MAX_CACHE_AGE, maxCacheAge, false);
if (sfLog().isInfoEnabled()) {
sfLog().info(" Downloading '" + url + "' to '" + localFile + "'. Blocksize: " + blocksize);
}
File target = new File(localFile);
bind(target);
download(url, target, blocksize, maxCacheAge);
if (sfLog().isInfoEnabled()) {
sfLog().info(" Download complete. File in: " + target);
}
new ComponentHelper(this)
.sfSelfDetachAndOrTerminate(null, "Download completed. File in: " + target, null, null);
} catch (Exception e) {
String errStr = ERROR_IN_DOWNLOAD + url + " to " + localFile;
if (log.isErrorEnabled()) {
log.error(errStr, e);
}
throw SmartFrogLifecycleException.forward(errStr, e, this);
}
}
/**
* Simple Download
*
* @param url url to download from
* @param localFile local file name
* @param blocksize block size to download
* @param maxCacheAge the max time (in seconds) that proxies should cache things. -1 = forever.
* @throws IOException for IO error
*/
public static void download(String url, File localFile, int blocksize, int maxCacheAge)
throws IOException {
// FileOutputStream object.
FileOutputStream fs = null;
// InputStream.
InputStream is = null;
byte[] b = new byte[blocksize];
int bytesRead;
boolean finished = false;
// create our output directories.
localFile.getParentFile().mkdirs();
try {
// open the URL,
URL endpoint = new URL(url);
URLConnection connection = endpoint.openConnection();
if (maxCacheAge >= 0) {
connection.addRequestProperty(CACHE_CONTROL, Integer.toString(maxCacheAge));
}
is = connection.getInputStream();
// open the file,
fs = new FileOutputStream(localFile);
// transfer the data
do {
bytesRead = is.read(b, 0, blocksize);
if (bytesRead > 0) {
fs.write(b, 0, bytesRead);
}
} while (bytesRead > 0);
// mark as finished
finished = true;
fs.close();
} finally {
FileSystem.close(fs);
FileSystem.close(is);
// delete any half-downloaded local file if
// something went wrong during download.
if (!finished && localFile.exists()) {
localFile.delete();
}
}
}
