Thursday, July 21, 2011

Sample code using android.app.DownloadManager

android.app.DownloadManager (introduced in API Level 9) is a system service that handles long-running HTTP downloads. Clients may request that a URI be downloaded to a particular destination file. The download manager will conduct the download in the background, taking care of HTTP interactions and retrying downloads after failures or across connectivity changes and system reboots.

android.app.DownloadManager
android.app.DownloadManager
android.app.DownloadManager

In order to permit your app download from internet, AndroidManifest.xml have to be modified to grant permission of "android.permission.INTERNET".

Java code:
package com.exercise.AndroidDownloadManager;

import java.io.FileInputStream;
import java.io.FileNotFoundException;

import android.app.Activity;
import android.app.DownloadManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.os.ParcelFileDescriptor;
import android.preference.PreferenceManager;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class AndroidDownloadManagerActivity extends Activity {

final String DOWNLOAD_FILE = "http://goo.gl/w3XV3";

final String strPref_Download_ID = "PREF_DOWNLOAD_ID";

SharedPreferences preferenceManager;
DownloadManager downloadManager;

ImageView image;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

preferenceManager
= PreferenceManager.getDefaultSharedPreferences(this);
downloadManager
= (DownloadManager)getSystemService(DOWNLOAD_SERVICE);

Button btnStartDownload = (Button)findViewById(R.id.startdownload);
btnStartDownload.setOnClickListener(btnStartDownloadOnClickListener);

image = (ImageView)findViewById(R.id.image);
}

Button.OnClickListener btnStartDownloadOnClickListener
= new Button.OnClickListener(){

@Override
public void onClick(View v) {
// TODO Auto-generated method stub

Uri downloadUri = Uri.parse(DOWNLOAD_FILE);
DownloadManager.Request request = new DownloadManager.Request(downloadUri);
long id = downloadManager.enqueue(request);

//Save the request id
Editor PrefEdit = preferenceManager.edit();
PrefEdit.putLong(strPref_Download_ID, id);
PrefEdit.commit();

}};

@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();

IntentFilter intentFilter
= new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE);
registerReceiver(downloadReceiver, intentFilter);
}

@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
unregisterReceiver(downloadReceiver);
}

private BroadcastReceiver downloadReceiver = new BroadcastReceiver() {

@Override
public void onReceive(Context arg0, Intent arg1) {
// TODO Auto-generated method stub
DownloadManager.Query query = new DownloadManager.Query();
query.setFilterById(preferenceManager.getLong(strPref_Download_ID, 0));
Cursor cursor = downloadManager.query(query);
if(cursor.moveToFirst()){
int columnIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS);
int status = cursor.getInt(columnIndex);
if(status == DownloadManager.STATUS_SUCCESSFUL){

//Retrieve the saved request id
long downloadID = preferenceManager.getLong(strPref_Download_ID, 0);

ParcelFileDescriptor file;
try {
file = downloadManager.openDownloadedFile(downloadID);
FileInputStream fileInputStream
= new ParcelFileDescriptor.AutoCloseInputStream(file);
Bitmap bm = BitmapFactory.decodeStream(fileInputStream);
image.setImageBitmap(bm);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
}
}
};
}


main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
<Button
android:id="@+id/startdownload"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Start Download"
/>
<ImageView
android:id="@+id/image"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</LinearLayout>



Download the files.

3 comments:

seifallah said...

Hi, i have some problems with the code above, DownloadManager.ACTION_DOWNLOAD_COMPLETE is not found... can you help me please? this is my mail : seifallah.azzabi@gmail.com

Andr.oid Eric said...

hello seifallah,

ACTION_DOWNLOAD_COMPLETE support API level 9 or higher.

akki said...

hi could u tell me how to download a file in android using service