Glide cache image on disk on background thread

Question

I want to use Glide to eagerly download images and cache them on disk for a future use. I want to call this functionality from a background thread.

I've read Glide's caching documentation, but it doesn't explain how to download the image without having an actual target right now. Then I found this issue and tried to use a similar approach, but whatever I try I get this exception:

java.lang.IllegalArgumentException: You must call this method on the main thread

So, how can I tell Glide to cache an image from a background thread?

EDIT: I really want to call Glide's methods on background thread. I know that I can use Handler and other ways to offload it to UI thread, but that's not what I'm asking.

Why don't you download ImageURLs and store it in Room DB and whenever you want, you can load the images from that DB instead. — Ümañg ßürmån, Sep 23 '18 at 09:14
@UmangBurman, storing images in DB is a bad idea (just like storing any other big binary objects). I could download the image, store it locally and keep the local URI, but that would amount to reinventing the wheel. First I want to know whether Glide can do that. — Vasiliy, Sep 23 '18 at 09:18

score 16 · Accepted Answer · answered Sep 23 '18 at 10:46

16

GlideApp.with(context)
    .downloadOnly()
    .diskCacheStrategy(DiskCacheStrategy.DATA) // Cache resource before it's decoded
    .load(url)
    .submit(Target.SIZE_ORIGINAL, Target.SIZE_ORIGINAL)
    .get() // Called on background thread

answered Sep 23 '18 at 10:46

veritas1

8,740
6
27
37

Exactly what I've been looking for. It even blocks the thread which is great. Thanks – Vasiliy Sep 23 '18 at 11:10

Ashwini Saini · Answer 2 · 2018-09-23T11:09:07.720

If want to load images in cache for future use in background thread then Glide have this functionality

here how you can do this

 //here i passing application context so our glide tie itself with application lifecycle

FutureTarget<File> future = Glide.with(getApplicationContext()).downloadOnly().load("your_image_url").submit();

now if you want to retrieve the saved path that you want to store in your DB then you can do

File file = future.get();
String path = file.getAbsolutePath();

you can also do this in just one line returning a path string like this

String path = Glide.with(getApplicationContext()).downloadOnly().load("your_image_url").submit().get().getAbsolutePath();

Thanks for your very elaborate answer. It's correct, but I decided to accept another answer because it turns out that using `DATA` cache strategy is mandatory in this case. — Vasiliy, Sep 23 '18 at 11:11

Trk · Answer 3 · 2018-09-23T09:41:41.923

Did I get the question right?

private class update extends AsyncTask<Void, Void, Void> {

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

    @Override
    protected Void doInBackground(Void... params) {
        try {
        RequestOptions options = new RequestOptions()
        .diskCacheStrategy(DiskCacheStrategy.ALL) // Saves all image resolution
        .centerCrop()
        .priority(Priority.HIGH)
        .placeholder(R.drawable.null_image_profile)
        .error(R.drawable.null_image_profile);

    Glide.with(context).load(imageUrl)
        .apply(options);

        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        //finish
    }
}

Nope. I don't have `profileImage`, but even if I would have one, call to `into` on background thread throws exception. — Vasiliy, Sep 23 '18 at 09:23

score 0 · Answer 4 · answered Sep 23 '18 at 09:24

0

You must call this method on the main thread

Wherever you call a method to use Glide or doing something from background, run inside:

runOnUiThread(new Runnable() {
                @Override
                public void run() {

              // Here, use glide or do your things on UiThread

            }
        });

To use it inside the main thread and then error should be gone.

answered Sep 23 '18 at 09:24

ʍѳђઽ૯ท

16,646
7
53
108

Thanks, but that's not what I asked. I'm interested in calling Glide's methods from background thread, not jumping back to UI thread. – Vasiliy Sep 23 '18 at 09:27
Correct! I just saw your edit. But, the point is, **`Glide` effects on UI** since it's an image loading library. So, no matter what you wanna achieve, it will throws exceptions like now. – ʍѳђઽ૯ท Sep 23 '18 at 09:28

Glide cache image on disk on background thread

4 Answers4

Linked