private long download()
throws NetworkErrorException, IOException, FileAlreadyExistException, NoMemoryException {
if (DEBUG) {
Log.v(TAG, "totalSize: " + totalSize);
}
/*
* check net work
*/
if (!NetworkUtils.isNetworkAvailable(context)) {
throw new NetworkErrorException("Network blocked.");
}
/*
* check file length
*/
client = AndroidHttpClient.newInstance("DownloadTask");
httpGet = new HttpGet(url);
response = client.execute(httpGet);
totalSize = response.getEntity().getContentLength();
if (!(response.getStatusLine().getStatusCode() == 200)) {
throw new NetworkErrorException("statusCode is not 200");
}
if (file.exists() && totalSize == file.length()) {
if (DEBUG) {
Log.v(null, "Output file already exists. Skipping download.");
}
throw new FileAlreadyExistException("Output file already exists. Skipping download.");
} else if (tempFile.exists()) {
httpGet.addHeader("Range", "bytes=" + tempFile.length() + "-");
previousFileSize = tempFile.length();
client.close();
client = AndroidHttpClient.newInstance("DownloadTask");
response = client.execute(httpGet);
if (DEBUG) {
Log.v(TAG, "File is not complete, download now.");
Log.v(TAG, "File length:" + tempFile.length() + " totalSize:" + totalSize);
}
}
/*
* check memory
*/
long storage = StorageUtils.getAvailableStorage();
if (DEBUG) {
Log.i(null, "storage:" + storage + " totalSize:" + totalSize);
}
if (totalSize - tempFile.length() > storage) {
throw new NoMemoryException("SD card no memory.");
}
/*
* start download
*/
outputStream = new ProgressReportingRandomAccessFile(tempFile, "rw");
publishProgress(0, (int) totalSize);
InputStream input = response.getEntity().getContent();
int bytesCopied = copy(input, outputStream);
if ((previousFileSize + bytesCopied) != totalSize || totalSize == -1 || interrupt) {
throw new IOException("Download incomplete: " + bytesCopied + " != " + totalSize);
}
if (DEBUG) {
Log.v(TAG, "Download completed successfully.");
}
return bytesCopied;
}
