How do I use disk caching in Picasso

Question

I am using Picasso to display image in my android app         load image This is within a activity so this context is activity    public void loadImage         Picasso picasso   Picasso with this        picasso setDebugging true       picasso load quiz getImageUrl    into quizImage       I have enable debugging and it always shows either red and green  But never shows yellow  Now if i load same image next time and internet is not available the image is not loaded   Questions    Does it not have local disk cache  How do i enable disk caching as i will be using same image multiple times  Do i need to add some disk permission to android manifest file

User · Answer

Add followning code in Application onCreate then use it normal      Picasso picasso   new Picasso Builder context               downloader new OkHttp3Downloader this Integer MAX VALUE                build        picasso setIndicatorsEnabled true       picasso setLoggingEnabled true       Picasso setSingletonInstance picasso     If you cache images first then do something like this in ProductImageDownloader doBackground  final Callback callback   new Callback                  Override             public void onSuccess                     downLatch countDown                    updateProgress                                Override             public void onError                     errorCount                    downLatch countDown                    updateProgress                                     Picasso with context  load Constants imagesUrl productModel getGalleryImage                     memoryPolicy MemoryPolicy NO CACHE  fetch callback           Picasso with context  load Constants imagesUrl productModel getLeftImage                     memoryPolicy MemoryPolicy NO CACHE  fetch callback           Picasso with context  load Constants imagesUrl productModel getRightImage                     memoryPolicy MemoryPolicy NO CACHE  fetch callback            try               downLatch await              catch  InterruptedException e                e printStackTrace                       if errorCount    0               products remove productModel               productModel isDownloaded   true              productsDatasource updateElseInsert productModel            else                 error occurred while downloading images for this product               ignore error for now                FIXME  9 27 2017 handle error             products remove productModel                      errorCount   0          downLatch   new CountDownLatch 3            if  products isEmpty      amp  amp  testCount    lt  30                 startDownloading products get 0             else                 all products with images are downloaded             publishProgress 100               and load your images like normal or with disk caching      Picasso with this  load Constants imagesUrl batterProduct getGalleryImage             networkPolicy NetworkPolicy OFFLINE           placeholder R drawable GalleryDefaultImage           error R drawable GalleryDefaultImage           into viewGallery     Note    Red color indicates that image is fetched from network   Green color indicates that image is fetched from cache memory   Blue color indicates that image is fetched from disk memory   Before releasing the app delete or set it false picasso setLoggingEnabled true    picasso setIndicatorsEnabled true   if not required  Thankx

User · Answer

This is what I did  Works well   First add the OkHttp to the gradle build file of the app module    compile  com squareup picasso picasso 2 5 2  compile  com squareup okhttp3 okhttp 3 10 0  compile  com jakewharton picasso picasso2-okhttp3-downloader 1 1 0    Then make a class extending Application  import android app Application   import com jakewharton picasso OkHttp3Downloader  import com squareup picasso Picasso   public class Global extends Application        Override     public void onCreate             super onCreate             Picasso Builder builder   new Picasso Builder this           builder downloader new OkHttp3Downloader this Integer MAX VALUE            Picasso built   builder build            built setIndicatorsEnabled true           built setLoggingEnabled true           Picasso setSingletonInstance built              add it to the Manifest file as follows     lt application         android name   Global              gt    lt  application gt    Now use Picasso as you normally would  No changes   EDIT   if you want to use cached images only  Call the library like this  I ve noticed that if we don t add the networkPolicy  images won t show up in an fully offline start even if they are cached  The code below solves the problem   Picasso with this               load url               networkPolicy NetworkPolicy OFFLINE               into imageView     EDIT  2  the problem with the above code is that if you clear cache  Picasso will keep looking for it offline in cache and fail  the following code example looks at the local cache  if not found offline  it goes online and replenishes the cache   Picasso with getActivity     load imageUrl   networkPolicy NetworkPolicy OFFLINE   into imageView  new Callback          Override     public void onSuccess                  Override     public void onError               Try again online if cache failed         Picasso with getActivity                     load posts get position  getImageUrl                     error R drawable header                   into imageView  new Callback                  Override             public void onSuccess                                  Override             public void onError                     Log v  Picasso   Could not fetch image

User · Answer

1  Picasso by default has cache  see ahmed hamdy answer   2  If your really must take image from disk cache and then network I recommend to write your own downloader   public class OkHttpDownloaderDiskCacheFirst extends OkHttpDownloader       public OkHttpDownloaderDiskCacheFirst OkHttpClient client            super client               Override     public Response load Uri uri  int networkPolicy  throws IOException           Response responseDiskCache   null          try               responseDiskCache   super load uri  1  lt  lt  2     NetworkPolicy OFFLINE           catch  Exception ignored       ignore  handle null later          if  responseDiskCache    null    responseDiskCache getContentLength   lt  0               return  super load uri  networkPolicy     user normal policy           else               return responseDiskCache                       And in Application singleton in method OnCreate use it with picasso           OkHttpClient okHttpClient   new OkHttpClient             okHttpClient setCache new Cache getCacheDir    100   1024   1024      100 MB cache  use Integer MAX VALUE if it is too low         OkHttpDownloader downloader   new OkHttpDownloaderDiskCacheFirst okHttpClient             Picasso Builder builder   new Picasso Builder this            builder downloader downloader            Picasso built   builder build             Picasso setSingletonInstance built     3  No permissions needed for defalut application cache folder

User · Answer

I don t know how good that solution is but it is definitely THE EASY ONE i just used in my app and it is working fine you load the image like that public void loadImage     Picasso picasso   Picasso get     picasso setIndicatorsEnabled true   picasso load quiz getImageUrl    into quizImage      You can get the bimap like that Bitmap bitmap   Picasso get   load quiz getImageUrl    get     Now covert that Bitmap into a JPG file and store in the in the cache  below is complete code for getting the bimap and caching it Thread thread   new Thread      public void run      File file   new File getCacheDir      quot   quot   member getMemberId      quot  jpg quot     try         Bitmap bitmap   Picasso get   load uri  get          FileOutputStream fOut   new FileOutputStream file                                                 bitmap compress Bitmap CompressFormat JPEG  100 new FileOutputStream file    fOut flush    fOut close          catch  Exception e      e printStackTrace                       thread start           the get   method of Piccasso need to be called on separate thread   i am saving that image also on that same thread  Once the image is saved you can get all the files like that List lt File gt  files   new LinkedList lt  gt  Arrays asList context getExternalCacheDir   listFiles       now you can find the file you are looking for like below for File file   files                   if file getName   equals  quot fileyouarelookingfor quot     quot  jpg quot        you need the name of the file  for example you are storing user image and the his image name is same as his id   you can call getId   on user to get the file name                     Picasso get      if file found then load it                              load file                               into mThumbnailImage                       return     return                               fetch it over the internet here because the file is not found

User · Answer

I use this code and worked  maybe useful for you   public static void makeImageRequest final View parentView final int id  final String imageUrl         final int defaultImageResId   R mipmap user      final ImageView imageView    ImageView  parentView findViewById id       Picasso with context               load imageUrl               networkPolicy NetworkPolicy OFFLINE               into imageView  new Callback                      Override                 public void onSuccess                     Log v  Picasso   fetch image success in first time                                         Override                 public void onError                           Try again online if cache failed                     Log v  Picasso   Could not fetch image in first time                           Picasso with context  load imageUrl  networkPolicy NetworkPolicy NO CACHE                               memoryPolicy MemoryPolicy NO CACHE  MemoryPolicy NO STORE  error defaultImageResId                               into imageView  new Callback                                       Override                                 public void onSuccess                                         Log v  Picasso   fetch image success in try again                                                                         Override                                 public void onError                                       Log v  Picasso   Could not fetch image again

User · Answer

For caching  I would use OkHttp interceptors to gain control over caching policy  Check out this sample that s included in the OkHttp library   RewriteResponseCacheControl java  Here s how I d use it with Picasso -  OkHttpClient okHttpClient   new OkHttpClient        okHttpClient networkInterceptors   add new Interceptor              Override         public Response intercept Chain chain  throws IOException               Response originalResponse   chain proceed chain request                 return originalResponse newBuilder   header  Cache-Control    max-age      60   60   24   365   build                           okHttpClient setCache new Cache mainActivity getCacheDir    Integer MAX VALUE        OkHttpDownloader okHttpDownloader   new OkHttpDownloader okHttpClient       Picasso picasso   new Picasso Builder mainActivity  downloader okHttpDownloader  build        picasso load imageURL  into viewHolder image

User · Answer

I had the same problem and used Glide library instead  Cache is out of the box there  https   github com bumptech glide

User · Answer

For the most updated version 2 71828 These are your answer   Q1  Does it not have local disk cache   A1  There is default caching within Picasso and the request flow just like this  App - gt  Memory - gt  Disk - gt  Server   Wherever they met their image first  they ll use that image and then stop the request flow  What about response flow  Don t worry  here it is   Server - gt  Disk - gt  Memory - gt  App   By default  they will store into a local disk first for the extended keeping cache  Then the memory  for the instance usage of the cache   You can use the built-in indicator in Picasso to see where images form by enabling this   Picasso get   setIndicatorEnabled true     It will show up a flag on the top left corner of your pictures    Red flag means the images come from the server   No caching at first load  Blue flag means the photos come from the local disk   Caching  Green flag means the images come from the memory   Instance Caching     Q2  How do I enable disk caching as I will be using the same image multiple times   A2  You don t have to enable it  It s the default   What you ll need to do is DISABLE it when you want your images always fresh  There is 2-way of disabled caching    Set  memoryPolicy   to NO CACHE and or NO STORE and the flow will look like this    NO CACHE will skip looking up images from memory   App - gt  Disk - gt  Server   NO STORE will skip store images in memory when the first load images   Server - gt  Disk - gt  App    Set  networkPolicy   to NO CACHE and or NO STORE and the flow will look like this    NO CACHE will skip looking up images from disk   App - gt  Memory - gt  Server   NO STORE will skip store images in the disk when the first load images   Server - gt  Memory - gt  App   You can DISABLE neither for fully no caching images  Here is an example    Picasso get   load imageUrl                memoryPolicy MemoryPolicy NO CACHE MemoryPolicy NO STORE                networkPolicy NetworkPolicy NO CACHE  NetworkPolicy NO STORE                fit   into banner     The flow of fully no caching and no storing will look like this   App - gt  Server   Request  Server - gt  App   Response   So  you may need this to minify your app storage usage also    Q3  Do I need to add some disk permission to android manifest file   A3  No  but don t forget to add the INTERNET permission for your HTTP request

User · Answer

1  answer of first question    according to Picasso Doc for With   method      The global default Picasso instance returned from with   is automatically initialized with defaults that are suitable to most implementations          LRU memory cache of 15  the available application RAM   Disk cache of 2  storage space up to 50MB but no less than 5MB        But Disk Cache operation for global Default Picasso is only available on API 14   2  answer of second Question   Picasso use the HTTP client request to Disk Cache operation So you can make your own http request header has property Cache-Control with max-age And create your own Static Picasso Instance instead of default Picasso By using  1  HttpResponseCache  Note  Works only for API 13    2  OkHttpClient  Works for all APIs   Example for using OkHttpClient to create your own Static Picasso class    First create a new class to get your own singleton picasso object   import android content Context  import com squareup picasso Downloader  import com squareup picasso OkHttpDownloader  import com squareup picasso Picasso   public class PicassoCache                   Static Picasso Instance             private static Picasso picassoInstance   null                  PicassoCache Constructor                param context application Context             private PicassoCache  Context context             Downloader downloader     new OkHttpDownloader context  Integer MAX VALUE           Picasso Builder builder   new Picasso Builder context               builder downloader downloader            picassoInstance   builder build                          Get Singleton Picasso Instance                param context application Context         return Picasso instance             public static Picasso getPicassoInstance  Context context             if  picassoInstance    null                 new PicassoCache context               return picassoInstance                     return picassoInstance             use your own singleton picasso object Instead of Picasso With     PicassoCache getPicassoInstance getContext    load imagePath  into imageView   3  answer for third question   you do not need any disk permissions for disk Cache operations  References  Github issue about disk cache  two Questions has been answered by  jake-wharton -  Question1 and Question2

[android] How do I use disk caching in Picasso?

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