How to Download a PDF File and open it in Android using an installed PDF Reader?

Actually this is fairly simple.

This simple code does this.

Uri path = Uri.fromFile(downloadFile(download_file_url));
				try {
					Intent intent = new Intent(Intent.ACTION_VIEW);
					intent.setDataAndType(path, "application/pdf");
					intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
					startActivity(intent);
					finish();
				} catch (ActivityNotFoundException e) {
					setError("PDF Reader application is not installed in your device");
				}

Here is the complete program that shows how to download a PDF File and open it in Android using an installed PDF Reader.

package com.example.openpdf;

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.content.ActivityNotFoundException;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.Typeface;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.view.Gravity;
import android.widget.TextView;

public class MainActivity extends Activity {

	TextView tv_loading;
	String dest_file_path = "test.pdf";
	int downloadedSize = 0, totalsize;
	String download_file_url = "http://ilabs.uw.edu/sites/default/files/sample_0.pdf";
	float per = 0;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		tv_loading = new TextView(this);
		setContentView(tv_loading);
		tv_loading.setGravity(Gravity.CENTER);
		tv_loading.setTypeface(null, Typeface.BOLD);
		downloadAndOpenPDF();
	}

	void downloadAndOpenPDF() {
		new Thread(new Runnable() {
			public void run() {
				Uri path = Uri.fromFile(downloadFile(download_file_url));
				try {
					Intent intent = new Intent(Intent.ACTION_VIEW);
					intent.setDataAndType(path, "application/pdf");
					intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
					startActivity(intent);
					finish();
				} catch (ActivityNotFoundException e) {
					tv_loading
							.setError("PDF Reader application is not installed in your device");
				}
			}
		}).start();
  
	}

	File downloadFile(String dwnload_file_path) {
		File file = null;
		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 = new File(SDCardRoot, dest_file_path);

			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();
			setText("Starting PDF download...");

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

			while ((bufferLength = inputStream.read(buffer)) > 0) {
				fileOutput.write(buffer, 0, bufferLength);
				downloadedSize += bufferLength;
				per = ((float) downloadedSize / totalsize) * 100;
				setText("Total PDF File size  : "
						+ (totalsize / 1024)
						+ " KB\n\nDownloading PDF " + (int) per
						+ "% complete");
			}
			// close the output stream when complete //
			fileOutput.close();
			setText("Download Complete. Open PDF Application installed in the device.");

		} catch (final MalformedURLException e) {
			setTextError("Some error occured. Press back and try again.",
					Color.RED);
		} catch (final IOException e) {
			setTextError("Some error occured. Press back and try again.",
					Color.RED);
		} catch (final Exception e) {
			setTextError(
					"Failed to download image. Please check your internet connection.",
					Color.RED);
		}
		return file;
	}

	void setTextError(final String message, final int color) {
		runOnUiThread(new Runnable() {
			public void run() {
				tv_loading.setTextColor(color);
				tv_loading.setText(message);
			}
		});

	}

	void setText(final String txt) {
		runOnUiThread(new Runnable() {
			public void run() {
				tv_loading.setText(txt);
			}
		});

	}

}