PhoneGap - Download and open a file (pdf, zip, image...)

In the last week I was looking for a solution to show a pdf using phonegap on android and iPhone. Searching on internet I figured out that a possible solution would be the Phonegap ChildBrowser plugin. This plugin basically open the WebView native component and show the address. After some modification (because i needed to use POST request and https protocol) of this plugin I managed to make it work on iPhone. So I did the same modification to the Android code but this time I was not so lucky. I started to find in the network and I came across the Giovesoft Blog post.

The idea was to download the file trough an http/s connection, saving it to the sdcard and opening it. Here is my version of his code. For the installation you can refere to the Giovesoft Blog post.

	import java.io.DataOutputStream;
	import java.io.File;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.net.HttpURLConnection;
	import java.net.URL;
	import java.util.Iterator;
	import javax.net.ssl.HttpsURLConnection;
	import org.json.JSONArray;
	import org.json.JSONException;
	import org.json.JSONObject;
	import android.content.Intent;
	import android.net.Uri;
	import android.os.Environment;
	import android.util.Log;
	import com.phonegap.api.Plugin;
	import com.phonegap.api.PluginResult;
	public class DownloadAndOpen extends Plugin {
	@Override
	public PluginResult execute(String action, JSONArray args, String callbackId) {
	if (action.equals("downloadFile")) {
	try {
	return this.downloadAndOpen(args.getString(0), args.getString(1), args.getString(2),
	args.getString(3), args.getString(4), args.getString(5), args.getString(6),
	args.getString(7));
	} catch (JSONException e) {
	return new PluginResult(PluginResult.Status.ERROR, "Param errrors");
	}
	} else {
	return new PluginResult(PluginResult.Status.INVALID_ACTION);
	}
	}
	private PluginResult downloadAndOpen(String fileUrl, String jsonPar, String isPost,
	String isHttps, String dirName, String fileName, String mimeType, String overwrite) {
	try {
	// address can be passed aldo in the json parameter with property name "address"
	// building parameters and address
	JSONObject jObject = new JSONObject(jsonPar);
	Iterator keys = jObject.keys();
	String dataToPost = "";
	String address = "";
	if (fileUrl != null || !(fileUrl.equals("")))
	address = fileUrl;
	while (keys.hasNext()) {
	String key = (String) keys.next();
	if (key.equals("address") && (fileUrl == null || fileUrl.equals("")))
	address = jObject.getString(key);
	else {
	if (dataToPost.length() > 0)
	dataToPost += "&";
	dataToPost += key;
	dataToPost += "=" + jObject.getString(key).replace("=", "%3D").replace("/", "%2F");
	}
	}
	if (address.equals(""))
	return new PluginResult(PluginResult.Status.ERROR, "Error: Url Address not found");
	// saving file on the sdcard
	// creating the directory if does not exists
	String finalDir = "";
	if (dirName == null)
	finalDir = Environment.getExternalStorageDirectory() + "/download/";
	else
	finalDir = Environment.getExternalStorageDirectory() + dirName;
	File dir = new File(finalDir);
	if (!dir.exists()) {
	dir.mkdirs();
	}
	// creating file
	String finalFile = "";
	if (fileName == null)
	finalFile = "tempfile";
	else
	finalFile = fileName;
	File file = new File(finalDir + finalFile);
	if (overwrite.equals("false") && file.exists()) {
	Log.d("DownloaderPlugin", "File already exist");
	return new PluginResult(PluginResult.Status.OK, "exist");
	} else {
	boolean isNewFileCreated = file.createNewFile();
	if (isNewFileCreated == false) {
	file.delete();
	file.createNewFile();
	}
	}
	// sending the request
	URL url = new URL(address);
	InputStream is;
	String requestMethod = "GET";
	if (isPost.equals("true"))
	requestMethod = "POST";
	if (isHttps.equals("true")) {
	HttpsURLConnection ucon = (HttpsURLConnection) url.openConnection();
	ucon.setRequestMethod(requestMethod);
	ucon.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
	ucon.setRequestProperty("Content-Length", Integer.toString(dataToPost.getBytes().length));
	ucon.setDoOutput(true);
	ucon.connect();
	DataOutputStream wr = new DataOutputStream(ucon.getOutputStream());
	wr.writeBytes(dataToPost);
	wr.flush();
	wr.close();
	is = ucon.getInputStream();
	} else {
	HttpURLConnection ucon = (HttpsURLConnection) url.openConnection();
	ucon.setRequestMethod(requestMethod);
	ucon.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
	ucon.setRequestProperty("Content-Length", Integer.toString(dataToPost.getBytes().length));
	ucon.setDoOutput(true);
	ucon.connect();
	DataOutputStream wr = new DataOutputStream(ucon.getOutputStream());
	wr.writeBytes(dataToPost);
	wr.flush();
	wr.close();
	is = ucon.getInputStream();
	}
	// processing the response
	byte[] buffer = new byte[1024];
	int len1 = 0;
	FileOutputStream fos = new FileOutputStream(file);
	while ((len1 = is.read(buffer)) > 0) {
	fos.write(buffer, 0, len1);
	}
	fos.close();
	// opening the file
	Uri path = Uri.fromFile(file);
	// retriving mime type
	String finalMimeType = "";
	if (mimeType == null || mimeType.equals(""))
	finalMimeType = mimeType;
	else {
	// most frequent mime types
	int lastIndexOfPoint = finalFile.lastIndexOf('.');
	String fileExt = finalFile.substring(lastIndexOfPoint + 1);
	if (fileExt.equals("zip"))
	finalMimeType = "application/x-compressed";
	else if (fileExt.equals("txt"))
	finalMimeType = "text/plain";
	else if (fileExt.equals("jpg") || fileExt.equals("jpeg") || fileExt.equals("jpe"))
	finalMimeType = "image/jpeg";
	else if (fileExt.equals("png"))
	finalMimeType = "image/png";
	else if (fileExt.equals("gif"))
	finalMimeType = "image/gif";
	else if (fileExt.equals("pdf"))
	finalMimeType = "application/pdf";
	// add more here if necessary...
	else
	finalMimeType = "text/plain";
	}
	// opening file
	Intent intent = new Intent(Intent.ACTION_VIEW);
	intent.setDataAndType(path, finalMimeType);
	intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
	this.ctx.startActivity(intent);
	} catch (IOException e) {
	return new PluginResult(PluginResult.Status.ERROR, "Error: " + e);
	} catch (JSONException e) {
	return new PluginResult(PluginResult.Status.ERROR, "Error: " + e);
	}
	return new PluginResult(PluginResult.Status.OK, fileName);
	}
	}

view raw DownloadAndOpen.java hosted with ❤ by GitHub

	function DownloadAndOpen() {
	}
	DownloadAndOpen.prototype.downloadAndOpen = function(fileUrl, jsonPar, isPost, isHttps, dirName, fileName, mimeType, overwrite, win, fail) {
	if (overwrite == false)
	overwrite = "false";
	else
	overwrite = "true";
	PhoneGap.exec(win, fail, "DownloadAndOpen", "downloadAndOpen", [fileUrl, jsonPar, isPost, isHttps, dirName, fileName, mimeType, overwrite]);
	};
	PhoneGap.addConstructor(function() {
	PhoneGap.addPlugin("downloader", new DownloadAndOpen());
	PluginManager.addService("DownloadAndOpen", "com.phonegap.plugins.downloader.DownloadAndOpen");
	});

view raw downloadandopen.js hosted with ❤ by GitHub

Looking forward for you comments! Ciao