Android下载文件的进度条提示

try {

//set the download URL, a url that points to a file on the internet

//this is the file to be downloaded

URL url = new URL("http://somewhere.com/some/webhosted/file");

 

//create the new connection

HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

 

//set up some things on the connection

urlConnection.setRequestMethod("GET");

urlConnection.setDoOutput(true);

 

//and connect!

urlConnection.connect();

 

//set the path where we want to save the file

//in this case, going to save it on the root directory of the

//sd card.

File SDCardRoot = Environment.getExternalStorageDirectory();

//create a new file, specifying the path, and the filename

//which we want to save the file as.

File file = new File(SDCardRoot,"somefile.ext");

 

//this will be used to write the downloaded data into the file we created

FileOutputStream fileOutput = new FileOutputStream(file);

 

//this will be used in reading the data from the internet

InputStream inputStream = urlConnection.getInputStream();

 

//this is the total size of the file

int totalSize = urlConnection.getContentLength();

//variable to store total downloaded bytes

int downloadedSize = 0;

 

//create a buffer...

byte[] buffer = new byte[1024];

int bufferLength = 0; //used to store a temporary size of the buffer

 

//now, read through the input buffer and write the contents to the file

while ( (bufferLength = inputStream.read(buffer)) > 0 ) {

//add the data in the buffer to the file in the file output stream (the file on the sd card

fileOutput.write(buffer, 0, bufferLength);

//add up the size so we know how much is downloaded

downloadedSize += bufferLength;

//this is where you would do something to report the prgress, like this maybe

updateProgress(downloadedSize, totalSize);

 

}

//close the output stream when done

fileOutput.close();

 

//catch some possible errors...

} catch (MalformedURLException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}