清除缓存（Retrofit / okHttp）

Question

I need a function to clear the complete Cache of my App. I´m using Retrofit with okHttp for my defaut Requests and Picasso for Image Loading. Is there any possibility?

I know that i can do CacheControl.FORCE_NETWORK for a specific Request, but i need to clear the whole Cache afterwards.

Any Ideas?

Answer 1

Here is a custom singleton which i made for picasso. You can use the clear cache method to clear the picasso cache. I can't really help you with retrofit as i haven't used that... just use the values as you please inside this class...

import android.content.Context;
import android.util.Log;

import com.jakewharton.picasso.OkHttp3Downloader;
import com.squareup.picasso.LruCache;
import com.squareup.picasso.Picasso;

import java.io.File;
import java.io.IOException;
import java.util.concurrent.TimeUnit;

import okhttp3.Cache;
import okhttp3.OkHttpClient;

//Singleton Class for Picasso Downloading, Caching and Displaying Images Library
public class PicassoSingleton {

private static Picasso mInstance;
private static long mDiskCacheSize = 50*1024*1024; //Disk Cache 50mb
private static int mMemoryCacheSize = 50*1024*1024; //Memory Cache 50mb, not currently using this. Using default implementation
private static OkHttpClient mOkHttpClient; //OK Http Client for downloading
private static OkHttp3Downloader okHttp3Downloader;
private static Cache diskCache;
private static LruCache lruCache;//not using it currently


public static synchronized Picasso getSharedInstance(Context context)
{
    if(mInstance == null) {
        if (context != null) {
            //Create disk cache folder if does not exist
            File cache = new File(context.getApplicationContext().getCacheDir(), "picasso_cache");
            if (!cache.exists()) {
                cache.mkdirs();
            }

            diskCache = new Cache(cache, mDiskCacheSize);
            //lruCache = new LruCache(mMemoryCacheSize);//not going to be using it, using default memory cache currently
            lruCache = new LruCache(context); // This is the default lrucache for picasso-> calculates and sets memory cache by itself

            //Create OK Http Client with retry enabled, timeout and disk cache
            mOkHttpClient = new OkHttpClient.Builder().cache(diskCache).connectTimeout(6000, TimeUnit.SECONDS).build();  //100 min cache timeout



            //For better performence in Memory use set memoryCache(Cache.NONE) in this builder (If needed)
            mInstance = new Picasso.Builder(context).memoryCache(lruCache).downloader(new OkHttp3Downloader(mOkHttpClient)).indicatorsEnabled(true).build();

        }
    }
    return mInstance;
}

public static void deletePicassoInstance()
{
    mInstance = null;
}

public static void clearLRUCache()
{
    if(lruCache!=null) {
        lruCache.clear();
        Log.d("FragmentCreate","clearing LRU cache");
    }

    lruCache = null;

}

public static void clearDiskCache(){
    try {
        if(diskCache!=null) {
            diskCache.evictAll();
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

    diskCache = null;

}
}

You can use it as follows:

 Picasso customPicasso= PicassoSingleton.getSharedInstance(youContext);
 Picasso.setSingletonInstance(customPicasso);

Then clear the cache as :

 PicassoSingleton.clearLRUCache();

Answer 2

That means there is no need for the caching feature. It allows you to pass a null into cache control. It removes the cache.

private OkHttpClient createOkHttpClient() {
    return new OkHttpClient.Builder()
            .readTimeout(60, TimeUnit.SECONDS)
            .connectTimeout(60 / 2, TimeUnit.SECONDS)
            .writeTimeout(60, TimeUnit.SECONDS)
            .cache(null)
            .build();
}