Volley Image Caching

Question

I am trying to understand Volley's image caching. I have a fragment with gridview inside it, which will load around 12-30 images. There images are retrieved from server and i am using NetworkImageView for loading these images.

I am able to display the images in the NetworkImageView and everything works fine. But, when I change from one fragment to another and come back to the previous fragment, in LogCat, I see that Volley is trying to fetch the images again.

I read Volley automatically takes care of Image Caching. When the image is cached in the first fragment, why is it trying to get the image again, when i came back from second to first? In the first place, is the LogCat data, showing Volley's image requests? or something else...

Below is my code:

In onCreate()

queue = Volley.newRequestQueue(getActivity());
imageLoader = new ImageLoader(queue, new ImageLoader.ImageCache() {
    private final LruCache<String, Bitmap> mCache = new LruCache<String, Bitmap>(
            10);

    public void putBitmap(String url, Bitmap bitmap) {
        mCache.put(url, bitmap);
    }

    public Bitmap getBitmap(String url) {
        return mCache.get(url);
    }
});

Logcat when loaded the fragment for first time :

02-18 14:21:20.724: D/Volley(14713): [4944] BasicNetwork.logSlowRequests: HTTP response for request=<[ ] http://xx.files.wordpress.com/2014/02/screen-shot-2014-02-17-at-11-57-29-pm.png 0x800c5bdc LOW 2> [lifetime=3782], [size=398563], [rc=200], [retryCount=0]
02-18 14:21:20.874: D/Volley(14713): [4943] BasicNetwork.logSlowRequests: HTTP response for request=<[ ] http://xx.files.wordpress.com/2014/02/st-vincent.jpg 0x800c5bdc LOW 3> [lifetime=3941], [size=501475], [rc=200], [retryCount=0]
02-18 14:21:20.894: D/Volley(14713): [1] Request.finish: 4181 ms: [ ] http://xx.files.wordpress.com/2014/02/screen-shot-2014-02-17-at-11-57-29-pm.png 0x800c5bdc LOW 2
02-18 14:21:20.974: D/Volley(14713): [1] Request.finish: 4260 ms: [ ] http://xx.files.wordpress.com/2014/02/st-vincent.jpg 0x800c5bdc LOW 3
02-18 14:21:20.994: D/dalvikvm(14713): GC_FOR_ALLOC freed 1914K, 6% free 68371K/72184K, paused 11ms, total 11ms
02-18 14:21:20.994: I/dalvikvm-heap(14713): Grow heap (frag case) to 72.368MB for 5843106-byte allocation
02-18 14:21:21.014: D/dalvikvm(14713): GC_FOR_ALLOC freed 1K, 5% free 74076K/77892K, paused 15ms, total 15ms
02-18 14:21:21.074: D/Volley(14713): [1] Request.finish: 4336 ms: [ ] http://xx.files.wordpress.com/2014/02/underwater.gif 0x800c5bdc LOW 8
02-18 14:21:21.214: D/Volley(14713): [4945] BasicNetwork.logSlowRequests: HTTP response for request=<[ ] http://xx.files.wordpress.com/2014/02/screen-shot-2014-02-17-at-4-24-04-pm.png 0x800c5bdc LOW 5> [lifetime=4155], [size=482380], [rc=200], [retryCount=0]
02-18 14:21:21.244: D/Volley(14713): [1] Request.finish: 4494 ms: [ ] http://xx.files.wordpress.com/2014/01/albarn-everyday-robots.jpg 0x800c5bdc LOW 9
02-18 14:21:21.274: D/Volley(14713): [1] Request.finish: 4551 ms: [ ] http://xx.files.wordpress.com/2014/02/screen-shot-2014-02-17-at-4-24-04-pm.png 0x800c5bdc LOW 5
02-18 14:21:21.994: D/Volley(14713): [1] Request.finish: 5244 ms: [ ] http://xx.files.wordpress.com/2014/02/macdemarco_baby.jpg 0x800c5bdc LOW 10
02-18 14:21:22.934: D/Volley(14713): [1] Request.finish: 6183 ms: [ ] http://xx.files.wordpress.com/2014/01/nenehcherry_lank01.jpg 0x800c5bdc LOW 11

When I come back to the same fragment the second time: Just visited second fragment and came back to first fragment - Not much a gap in between..

02-18 14:27:46.164: D/dalvikvm(14713): GC_FOR_ALLOC freed 29047K, 26% free 91776K/122752K, paused 23ms, total 23ms
02-18 14:27:47.994: D/dalvikvm(14713): GC_FOR_ALLOC freed 2957K, 21% free 97010K/122752K, paused 20ms, total 20ms
02-18 14:27:48.274: D/Volley(14713): [1] Request.finish: 3244 ms: [ ] http://xx.files.wordpress.com/2014/02/screen-shot-2014-02-17-at-2-58-16-pm.png 0x800c5bdc LOW 6
02-18 14:27:48.294: D/dalvikvm(14713): GC_FOR_ALLOC freed 2007K, 21% free 97932K/122752K, paused 14ms, total 14ms
02-18 14:27:48.324: D/Volley(14713): [4956] BasicNetwork.logSlowRequests: HTTP response for request=<[ ] http://xx.files.wordpress.com/2014/02/screen-shot-2014-02-17-at-11-57-29-pm.png 0x800c5bdc LOW 2> [lifetime=3272], [size=398563], [rc=200], [retryCount=0]
02-18 14:27:48.484: D/Volley(14713): [1] Request.finish: 3456 ms: [ ] http://xx.files.wordpress.com/2014/02/screen-shot-2014-02-17-at-11-57-29-pm.png 0x800c5bdc LOW 2
02-18 14:27:48.974: D/dalvikvm(14713): GC_FOR_ALLOC freed 1030K, 15% free 104815K/122752K, paused 56ms, total 56ms
02-18 14:27:49.054: D/Volley(14713): [1] Request.finish: 4022 ms: [ ] http://xx.files.wordpress.com/2014/02/screen-shot-2014-02-17-at-4-24-04-pm.png 0x800c5bdc LOW 5
02-18 14:27:49.314: D/Volley(14713): [1] Request.finish: 4276 ms: [ ] http://xx.files.wordpress.com/2014/01/albarn-everyday-robots.jpg 0x800c5bdc LOW 9
02-18 14:27:49.374: D/Volley(14713): [1] Request.finish: 4325 ms: [ ] http://xx.files.wordpress.com/2014/01/nenehcherry_lank01.jpg 0x800c5bdc LOW 11
02-18 14:27:49.404: D/Volley(14713): [1] Request.finish: 4355 ms: [ ] http://xx.files.wordpress.com/2014/02/macdemarco_baby.jpg 0x800c5bdc LOW 10
02-18 14:27:49.654: D/dalvikvm(14713): GC_FOR_ALLOC freed 1456K, 12% free 108705K/122752K, paused 27ms, total 27ms
02-18 14:27:49.734: D/Volley(14713): [1] Request.finish: 4691 ms: [ ] http://xx.files.wordpress.com/2014/02/underwater.gif 0x800c5bdc LOW 8
02-18 14:27:50.304: D/dalvikvm(14713): GC_FOR_ALLOC freed 11584K, 16% free 103314K/122752K, paused 47ms, total 47ms
02-18 14:27:50.334: D/Volley(14713): [1] Request.finish: 5281 ms: [ ] http://xx.files.wordpress.com/2014/02/echo-and-the-bunnymen.jpg 0x800c5bdc LOW 12

As the links show, Volley is accessing the same URLs. Is Volley trying to get images from server? or is it just showing the urls that it is loading from cache?

How do I make Volley cache images? If it's not handling the caching right now, with my code above, what should i do to achieve it?

I have tried changing the maxSize value from 10 to 100*1024*1024 (100MB) but that didn't stop from Volley outputting the same values.

Answer 1

Volley did not gave caching option directly. you have to make your own with in the tool provide by Volley. See Network Image caching, Jake Wharton had written about caching mechanism using Volley. Jake Wharton's Volley Customization

Answer 2

You can see in the link below, the continuation of my question for implementing Image Caching with Volley using Jake Wharton's DiskLruCache and VolleyImageCacheExample. It's working as expected and images are getting cached. Thanks for all your help.

JakeWharton's DiskLruCache - How to Implement with Volley?