Exo Player Cache | Progressive Loading | Cache Media Source

CacheMediaSource.java

import android.content.Context;

import androidx.annotation.NonNull;

import com.google.android.exoplayer2.MediaItem;
import com.google.android.exoplayer2.source.MediaSource;
import com.google.android.exoplayer2.source.ProgressiveMediaSource;
import com.google.android.exoplayer2.upstream.DataSource;
import com.google.android.exoplayer2.upstream.DefaultDataSource;
import com.google.android.exoplayer2.upstream.DefaultHttpDataSource;
import com.google.android.exoplayer2.upstream.cache.CacheDataSource;
import com.google.android.exoplayer2.upstream.cache.LeastRecentlyUsedCacheEvictor;
import com.google.android.exoplayer2.upstream.cache.SimpleCache;

import java.io.File;

//com.google.android.exoplayer:exoplayer:2.18.6
//MediaSource source = CacheMediaSource.Builder(context, path).build();
//exoPlayer.setMediaSource(source);
public class CacheMediaSource implements DataSource.Factory {

    private static SimpleCache cache;
    private final DefaultDataSource.Factory defaultDataSourceFactory;
    private String source = "";

    private CacheMediaSource(Context context) {
        buildCache(context);
        DefaultHttpDataSource.Factory httpSourceFactory = new DefaultHttpDataSource.Factory();
        defaultDataSourceFactory = new DefaultDataSource.Factory(context, httpSourceFactory);
    }

    private static synchronized void buildCache(Context context) {
        if (cache == null) {
            File cacheDir = new File(context.getCacheDir(), /*child*/ "exo-cache");
            LeastRecentlyUsedCacheEvictor evict = new LeastRecentlyUsedCacheEvictor(200 * 1024 * 1024); // for 200Mb
            cache = new SimpleCache(cacheDir, evict);
        }
    }

    public static CacheMediaSource Builder(Context context) {
        return CacheMediaSource.Builder(context, "");
    }

    public static CacheMediaSource Builder(Context context, String source) {
        CacheMediaSource exoCache = new CacheMediaSource(context);
        exoCache.source = source;
        return exoCache;
    }

    public CacheMediaSource source(String source) {
        this.source = source;
        return this;
    }

    public MediaSource build() {
        MediaItem item = MediaItem.fromUri(source);
        return new ProgressiveMediaSource
                .Factory(this)
                .createMediaSource(item);
    }

    @NonNull
    @Override
    public DataSource createDataSource() {
        return new CacheDataSource(
                cache,
                defaultDataSourceFactory.createDataSource(),
                /*flags*/ CacheDataSource.FLAG_BLOCK_ON_CACHE | CacheDataSource.FLAG_IGNORE_CACHE_ON_ERROR
        );
    }
}