Download and install android app

Question

In my android app i have 1 button to download the .apk and and then im adding another to install the .apk, when you click the download button it downloads the .apk from my website and puts it in the root of your sdcard storage! what do i have to add so when the user clicks the button named "install" it takes them to the install screen??

MainActvity.java

package cydia.jb.download;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import android.app.Activity;
import android.app.Dialog;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

ProgressBar pb;
Dialog dialog;
int downloadedSize = 0;
int totalSize = 0;
TextView cur_val;
String dwnload_file_path = "http://diordnakclab.net23.net/cydia/Cydia.apk";
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Button b = (Button) findViewById(R.id.button1);
    b.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
             showProgress(dwnload_file_path);

                new Thread(new Runnable() {
                    public void run() {
                         downloadFile();
                    }
                  }).start();
        }
    });
}

void downloadFile(){

    try {
        URL url = new URL(dwnload_file_path);
        HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
        urlConnection.setRequestMethod("GET");
        urlConnection.setDoOutput(true);

        //connect
        urlConnection.connect();

        //set the path where we want to save the file           
        File SDCardRoot = Environment.getExternalStorageDirectory(); 
        //create a new file, to save the downloaded file 
        File file = new File(SDCardRoot,"Cydia.apk");

        FileOutputStream fileOutput = new FileOutputStream(file);

        //Stream used for reading the data from the internet
        InputStream inputStream = urlConnection.getInputStream();

        //this is the total size of the file which we are downloading
        totalSize = urlConnection.getContentLength();

        runOnUiThread(new Runnable() {
            public void run() {
                pb.setMax(totalSize);
            }               
        });

        //create a buffer...
        byte[] buffer = new byte[1024];
        int bufferLength = 0;

        while ( (bufferLength = inputStream.read(buffer)) > 0 ) {
            fileOutput.write(buffer, 0, bufferLength);
            downloadedSize += bufferLength;
            // update the progressbar //
            runOnUiThread(new Runnable() {
                public void run() {
                    pb.setProgress(downloadedSize);
                    float per = ((float)downloadedSize/totalSize) * 100;
                    cur_val.setText("Downloaded " + downloadedSize + "KB / " +   totalSize + "KB (" + (int)per + "%)" );
                }
            });
        }
        //close the output stream when complete //
        fileOutput.close();
        runOnUiThread(new Runnable() {
            public void run() {
                // pb.dismiss(); // if you want close it..
            }
        });         

    } catch (final MalformedURLException e) {
        showError("Error : MalformedURLException " + e);        
        e.printStackTrace();
    } catch (final IOException e) {
        showError("Error : IOException " + e);          
        e.printStackTrace();
    }
    catch (final Exception e) {
        showError("Error : Please check your internet connection " + e);
    }       
}

void showError(final String err){
    runOnUiThread(new Runnable() {
        public void run() {
            Toast.makeText(MainActivity.this, err, Toast.LENGTH_LONG).show();
        }
    });
}

void showProgress(String file_path){
    dialog = new Dialog(MainActivity.this);
    dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
    dialog.setContentView(R.layout.myprogressdialog);
    dialog.setTitle("Download Progress");

    TextView text = (TextView) dialog.findViewById(R.id.tv1);
    text.setText("Downloading file from ... " + file_path);
    cur_val = (TextView) dialog.findViewById(R.id.cur_pg_tv);
    cur_val.setText("Starting download...");
    dialog.show();

    pb = (ProgressBar)dialog.findViewById(R.id.progress_bar);
    pb.setProgress(0);
    pb.setProgressDrawable(getResources().getDrawable(R.drawable.green_progress));  
}
}

CydiaManafest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="cydia.jb.download"
android:versionCode="4"
android:versionName="4.0" >

<uses-sdk
    android:minSdkVersion="16"
    android:targetSdkVersion="17" />
    <uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="cydia.jb.download.MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

</manifest>

Answer 1

here is the code

button1 = (Button) findViewById(R.id.button1);

button1.setOnClickListener(new OnClickListener()
{
    public void onClick(View v1) 
    {
        Intent promptInstall = new Intent(Intent.ACTION_VIEW)
            .setData(Uri.parse("file:///path/to/your.apk"))
            .setType("application/vnd.android.package-archive");
        startActivity(promptInstall);
    } 
}