Cancel/remove download from DownloadManager.

In the last exercise, "Set the title of Download on notification, setTitle()", The download query will be alway here after started, even close you app. Such that you always see the Toast of the status (such as "SUCCESSFUL") when you app start. So you have to call remove() method to clear the download, or if you want to stop it before finished.

package com.exercise.AndroidDownloadManager;

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

import android.app.Activity;
import android.app.DownloadManager;
import android.app.DownloadManager.Request;
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;
import android.widget.Toast;

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);
   
   /*
    *  request.setAllowedNetworkTypes()-
    *  Restrict the types of networks over which this download may proceed. 
    *  By default, all network types are allowed.
    *  - Request.NETWORK_WIFI
    *  - Request.NETWORK_MOBILE
    *  - Request.NETWORK_WIFI | Request.NETWORK_MOBILE
    *  
    *  request.setAllowedOverRoaming(false) -
    *  Set whether this download may proceed over a roaming connection. 
    *  By default, roaming is allowed.
    */
   request.setAllowedNetworkTypes(Request.NETWORK_WIFI);
   request.setAllowedOverRoaming(false);
   
   
   /*
    *  Set Title of Download
    */
   request.setTitle("Android-er Download!");
   
   /*
    *  (for API 11 or higher!)
    *  Display Download in Notification
    */
   //request.setNotificationVisibility(Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
     
   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();
  
  CheckDwnloadStatus();

  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
   CheckDwnloadStatus();
  } 
 };
 
 private void CheckDwnloadStatus(){

  // TODO Auto-generated method stub
  DownloadManager.Query query = new DownloadManager.Query();
  long id = preferenceManager.getLong(strPref_Download_ID, 0);
  query.setFilterById(id);
  Cursor cursor = downloadManager.query(query);
  if(cursor.moveToFirst()){
   int columnIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS);
   int status = cursor.getInt(columnIndex);
   int columnReason = cursor.getColumnIndex(DownloadManager.COLUMN_REASON);
   int reason = cursor.getInt(columnReason);
   
   switch(status){
   case DownloadManager.STATUS_FAILED:
    String failedReason = "";
    switch(reason){
    case DownloadManager.ERROR_CANNOT_RESUME:
     failedReason = "ERROR_CANNOT_RESUME";
     break;
    case DownloadManager.ERROR_DEVICE_NOT_FOUND:
     failedReason = "ERROR_DEVICE_NOT_FOUND";
     break;
    case DownloadManager.ERROR_FILE_ALREADY_EXISTS:
     failedReason = "ERROR_FILE_ALREADY_EXISTS";
     break;
    case DownloadManager.ERROR_FILE_ERROR:
     failedReason = "ERROR_FILE_ERROR";
     break;
    case DownloadManager.ERROR_HTTP_DATA_ERROR:
     failedReason = "ERROR_HTTP_DATA_ERROR";
     break;
    case DownloadManager.ERROR_INSUFFICIENT_SPACE:
     failedReason = "ERROR_INSUFFICIENT_SPACE";
     break;
    case DownloadManager.ERROR_TOO_MANY_REDIRECTS:
     failedReason = "ERROR_TOO_MANY_REDIRECTS";
     break;
    case DownloadManager.ERROR_UNHANDLED_HTTP_CODE:
     failedReason = "ERROR_UNHANDLED_HTTP_CODE";
     break;
    case DownloadManager.ERROR_UNKNOWN:
     failedReason = "ERROR_UNKNOWN";
     break;
    }

    Toast.makeText(AndroidDownloadManagerActivity.this, 
      "FAILED: " + failedReason, 
      Toast.LENGTH_LONG).show();
    break;
   case DownloadManager.STATUS_PAUSED:
    String pausedReason = "";
    
    switch(reason){
    case DownloadManager.PAUSED_QUEUED_FOR_WIFI:
     pausedReason = "PAUSED_QUEUED_FOR_WIFI";
     break;
    case DownloadManager.PAUSED_UNKNOWN:
     pausedReason = "PAUSED_UNKNOWN";
     break;
    case DownloadManager.PAUSED_WAITING_FOR_NETWORK:
     pausedReason = "PAUSED_WAITING_FOR_NETWORK";
     break;
    case DownloadManager.PAUSED_WAITING_TO_RETRY:
     pausedReason = "PAUSED_WAITING_TO_RETRY";
     break;
    }
    
    Toast.makeText(AndroidDownloadManagerActivity.this, 
      "PAUSED: " + pausedReason, 
      Toast.LENGTH_LONG).show();
    break;
   case DownloadManager.STATUS_PENDING:
    Toast.makeText(AndroidDownloadManagerActivity.this, 
      "PENDING", 
      Toast.LENGTH_LONG).show();
    break;
   case DownloadManager.STATUS_RUNNING:
    Toast.makeText(AndroidDownloadManagerActivity.this, 
      "RUNNING", 
      Toast.LENGTH_LONG).show();
    break;
   case DownloadManager.STATUS_SUCCESSFUL:
    
    Toast.makeText(AndroidDownloadManagerActivity.this, 
      "SUCCESSFUL", 
      Toast.LENGTH_LONG).show();
    GetFile();
    downloadManager.remove(id);
    break;
   } 
  } 
 }
 
 private void GetFile(){
  //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();
  } 
 }
}