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 -> Memory -> Disk -> 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 -> Disk -> Memory -> 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.
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.
.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 -> Disk -> Server
NO_STORE will skip store images in memory when the first load images.
Server -> Disk -> App
.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 -> Memory -> Server
NO_STORE will skip store images in the disk when the first load images.
Server -> Memory -> 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 -> Server //Request
Server -> 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.