【发布时间】：2014-04-18 09:48:17
【问题描述】：
我正在尝试创建一个服务来从我的本地网络中的服务器下载文件。每个想法似乎都很好，服务启动，当下载结束时，当我检查 sdcard 中的文件时找到了一个emty文件，谁能帮我解决这个问题，先谢谢了。
此服务 DownloadService ：
public class DownloadService extends Service{
private static String file_url = "http://192.168.1.150:8080/TestAndroid/DownloadServlet/Desert.pdf";
public int onStartCommand(Intent intent, int flags, int startId) {
Toast.makeText(getBaseContext(), "Service started", Toast.LENGTH_LONG).show();
new DownloadFileFromURL().execute(file_url);//Appel vers Asynctask
return START_STICKY;
}
/**
* Background Async Task to download file
* */
class DownloadFileFromURL extends AsyncTask<String, String, String> {
/**
* Before starting background thread
* Show Progress Bar Dialog
* */
public String[] listDebitDown = new String[163] ;
int compteur = 0;
@Override
protected void onPreExecute() {
super.onPreExecute();
// showDialog(progress_bar_type);
}
/**
* Downloading file in background thread
* */
@Override
protected String doInBackground(String... f_url) {
int count;
try {
URL url = new URL(f_url[0]);
URLConnection conection = url.openConnection();
conection.connect();
// this will be useful so that you can show a tipical 0-100% progress bar
int lenghtOfFile = conection.getContentLength();
// download the file
InputStream input = new BufferedInputStream(url.openStream(), 8192);
// Output stream
OutputStream output = new FileOutputStream("/sdcard/downloadedfile.pdf");//jpg
int nombrePaquets ;
nombrePaquets = (lenghtOfFile / 1024 ) + (lenghtOfFile % 1024 );
byte data[] = new byte[1024];
String tabResult [] = new String [nombrePaquets];
long total = 0;
long startTotalTime = System.currentTimeMillis();
long passedTime =0;
// Get ListView object from xml
// listView = (ListView) findViewById(R.id.listView1);
while ((count = input.read(data)) != -1) {
total += count;
// writing data to file
output.write(data, 0, count);
}
// flushing output
output.flush();
// closing streams
output.close();
input.close();
} catch (Exception e) {
Log.e("Error***: ", e.getMessage());
}
return null;
}
/**
* After completing background task
* Dismiss the progress dialog
* **/
@Override
protected void onPostExecute(String file_url) {
Toast.makeText(getApplicationContext(),
"téléchargement términé " , Toast.LENGTH_LONG)
.show();
Toast.makeText(getApplicationContext(),
"Passagr "+ listDebitDown[10] , Toast.LENGTH_LONG)
.show();
// Displaying downloaded image into image view
// Reading image path from sdcard
String imagePath = Environment.getExternalStorageDirectory().toString() + "/downloadedfile.pdf";//jpg
Log.i("imagePath", imagePath);
Log.i("isExternalStorageWritable", isExternalStorageWritable() + "true" );
}
}
public boolean isExternalStorageWritable() {
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
Log.i("isExternalStorageWritable", "true" );
return true;
}
return false;
}
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
}
PS：我添加了权限，服务器可以ping到手机，wamp服务器是ON的。
【问题讨论】：
-
您没有在 doInBackground() 中返回文件路径。你只返回null。
-
感谢您的回复。所以它应该返回什么？ @Yuvaraja
-
对不起！我想你会在执行后考虑文件路径。你没有考虑返回的文件路径。