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Android Series: Download files with Progress Dialog

26 Mar

Android Series: Download files with Progress Dialog

Today, I will present a short tutorial on how to download files in android displaying at the same time download progress based on the bytes downloaded. For the purpose of this tutorial we will use build in AsyncTask mechanism together with ProgressDialog class.
The whole application consists of one activity displaying a ‘Start Download’ button. Clicking our startbutton we initialize file download passing to the asynctask the url or the resource we want to download.


AndroAsync.java

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package com.softwarepassion;

import java.io.BufferedInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;

import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class AndroAsync extends Activity {

public static final int DIALOG_DOWNLOAD_PROGRESS = 0;
private Button startBtn;
private ProgressDialog mProgressDialog;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
startBtn = (Button)findViewById(R.id.startBtn);
startBtn.setOnClickListener(new OnClickListener(){
public void onClick(View v) {
startDownload();
}
});
}

private void startDownload() {
String url = “http://farm1.static.flickr.com/114/298125983_0e4bf66782_b.jpg”;
new DownloadFileAsync().execute(url);
}
@Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DIALOG_DOWNLOAD_PROGRESS:
mProgressDialog = new ProgressDialog(this);
mProgressDialog.setMessage(“Downloading file..”);
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
mProgressDialog.setCancelable(false);
mProgressDialog.show();
return mProgressDialog;
default:
return null;
}
}
class DownloadFileAsync extends AsyncTask<String, String, String> {

@Override
protected void onPreExecute() {
super.onPreExecute();
showDialog(DIALOG_DOWNLOAD_PROGRESS);
}

@Override
protected String doInBackground(String… aurl) {
int count;

try {
URL url = new URL(aurl[0]);
URLConnection conexion = url.openConnection();
conexion.connect();

int lenghtOfFile = conexion.getContentLength();
Log.d(“ANDRO_ASYNC”, “Lenght of file: ” + lenghtOfFile);

InputStream input = new BufferedInputStream(url.openStream());
OutputStream output = new FileOutputStream(“/sdcard/some_photo_from_gdansk_poland.jpg”);

byte data[] = new byte[1024];

long total = 0;

while ((count = input.read(data)) != -1) {
total += count;
publishProgress(“”+(int)((total*100)/lenghtOfFile));
output.write(data, 0, count);
}

output.flush();
output.close();
input.close();
} catch (Exception e) {}
return null;

}
protected void onProgressUpdate(String… progress) {
Log.d(“ANDRO_ASYNC”,progress[0]);
mProgressDialog.setProgress(Integer.parseInt(progress[0]));
}

@Override
protected void onPostExecute(String unused) {
dismissDialog(DIALOG_DOWNLOAD_PROGRESS);
}
}
}

layout file (main.xml) :

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<?xml version=”1.0″ encoding=”utf-8″?>
<LinearLayout xmlns:android=”http://schemas.android.com/apk/res/android&#8221;
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:text=”Start long running task..”
android:id=”@+id/startBtn”
android:layout_width=”fill_parent”
android:layout_height=”wrap_content”>
</Button>
</LinearLayout>

While downloadin a file from the internet remember to add INTERNET permission in AndroidManifest.xml

1
<uses-permission android:name=”android.permission.INTERNET” />

Check your sd card folder for what was downloaded and enjoy!

 

Referenced by: http://www.softwarepassion.com/android-series-download-files-with-progress-dialog/

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1 Comment

Posted by on March 26, 2012 in Android

 

One response to “Android Series: Download files with Progress Dialog

  1. Meera

    November 5, 2012 at 5:19 PM

    Very useful example.Thanks
    here is another useful example that lets you use ProgressDialog using threads and handlers also . http://blog.creatiosoft.com/?p=1316

     

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