Fetch images and metadata from PHP server to android - php

Question

My android app needs to fetch some info from a php server that hosts a MySQL database. It works fine so far. The server encodes the info into JSON and sends it and then I can parse it well.
But now I need to also fetch an image together with each row of info I get from the DB. The info I'm getting has a field where it specifies the path where the correspondent image is located in the filesystem.
So, once I get the paths of the images, how do I read them so that I can send them together with the info rows obtained? Can I JSON encode the images together with the info? Or should I read them one by one with readfile once I have the info in the android app? If it can be done with JSON, how do you parse the data of the image afterwards? Can you provide an example?

Answer 1

One way to get an image in textform would be to use base64. I have used it with several webservices and there is decoders for Android out there, actually. There is one in the source code since API level 8. http://developer.android.com/reference/android/util/Base64.html but since I want to target other levels I include it myself.
One easy way would then be to save the image in a database instead as a file.

Answer 2

This is what I did to fetch the images together with the data. I post it so that if it can help someone.
This is the part of the PHP script that sends the data in the server side:
$i=0;
//$sql contains the result from the query of the data
while($row=mysql_fetch_array($sql)){
$output[]=$row;
//Here we fetch the image from the files table
$query = "SELECT path, type FROM FILES WHERE poi_id = '" . mysql_real_escape_string(trim($output[$i][0])) . "'";
$r = mysql_query($query);
$img = mysql_fetch_array($r);
$bin = base64_encode_image($img[0]);
//Let's append the image and the type to the data output.
$output[$i]['img'] = $bin;
$output[$i]['type'] = $img[1];
$i++;
}
//This method sends the response to the Android app
//You can just use echo(json_encode($output));
RestUtils::sendResponse(200, json_encode($output), 'application/json');
And then in the Android app, after parsing the JSON, you can save the base64 string as an image to the file system like this:
public void createImage(String image, String name){
try{
byte[] imageAsBytes = Base64.decode(image.getBytes(), Base64.DEFAULT);
Bitmap img_bitmap = BitmapFactory.decodeByteArray(imageAsBytes, 0, imageAsBytes.length);
FileOutputStream fos = openFileOutput(name, Context.MODE_WORLD_READABLE);
img_bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
fos.flush();
fos.close();
}
catch(Exception e){
e.printStackTrace();
}
}

Answer 3

for downloading image from path
public void DownloadImageFromPath(String path){
InputStream in =null;
Bitmap bmp=null;
ImageView iv = (ImageView)findViewById(R.id.img1);
int responseCode = -1;
try{
URL url = new URL(path);//"http://192.xx.xx.xx/mypath/img1.jpg
HttpURLConnection con = (HttpURLConnection)url.openConnection();
con.setDoInput(true);
con.connect();
responseCode = con.getResponseCode();
if(responseCode == HttpURLConnection.HTTP_OK)
{
//download
in = con.getInputStream();
bmp = BitmapFactory.decodeStream(in);
in.close();
iv.setImageBitmap(bmp);
}
}
catch(Exception ex){
Log.e("Exception",ex.toString());
}
}