Error:
java.lang.IllegalStateException: ImageLoader must be init with configuration before using
I'm struggling to display the images in my approach of putting the gridview inside a fragments. PostListAdapter where i call UniversalImageLoader:
public class ViewHolder extends RecyclerView.ViewHolder{
    ImageView mPostImage;
    public ViewHolder(View itemView) {
        super(itemView);
        mPostImage = (ImageView) itemView.findViewById(R.id.post_image1);
        int gridWidth = mContext.getResources().getDisplayMetrics().widthPixels;
        int imageWidth = gridWidth/NUM_GRID_COLUMNS;
        mPostImage.setMaxHeight(imageWidth);
        mPostImage.setMaxWidth(imageWidth);
    }
}
public PostListAdapter(Context context, ArrayList<Post> posts) {
    mPosts = posts;
    mContext = context;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(mContext).inflate(R.layout.layout_view_post, parent, false);
    return new ViewHolder(view);
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
    UniversalImageLoader.setImage(mPosts.get(position).getImage(), holder.mPostImage);
}
@Override
public int getItemCount() {
    return mPosts.size();
}
Fragment (method) where i call PostAdapter:
 private void setupPostsList(){
    GridLayoutManager gridLayoutManager = new GridLayoutManager(getActivity(), NUM_GRID_COLUMNS);
    mRecyclerView.setLayoutManager(gridLayoutManager);
    mAdapter = new PostListAdapter(getActivity(), mPosts);
    mRecyclerView.setAdapter(mAdapter);
}
This is UniversalImageLoader class:
public class UniversalImageLoader 
private static final int defaultImage = R.drawable.ic_launcher_background;
private Context mContext;
public UniversalImageLoader(Context context) {
    mContext = context;
}
public ImageLoaderConfiguration getConfig(){
    DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder()
            .showImageOnLoading(defaultImage)
            .showImageForEmptyUri(defaultImage)
            .showImageOnFail(defaultImage)
            .considerExifParams(true)
            .cacheOnDisk(true).cacheInMemory(true)
            .cacheOnDisk(true).resetViewBeforeLoading(true)
            .imageScaleType(ImageScaleType.EXACTLY)
            .displayer(new FadeInBitmapDisplayer(300)).build();
    ImageLoaderConfiguration configuration = new ImageLoaderConfiguration.Builder(mContext)
            .defaultDisplayImageOptions(defaultOptions)
            .memoryCache(new WeakMemoryCache())
            .diskCacheSize(100 * 1024 * 1024).build();
    return configuration;
}
public static void setImage(String imgURL, ImageView image){
    ImageLoader imageLoader = ImageLoader.getInstance();
    imageLoader.displayImage(imgURL, image);
}
Logcat:
 java.lang.IllegalStateException: ImageLoader must be init with configuration before using
                                                                          at com.test.test.test.util.UniversalImageLoader.setImage(UniversalImageLoader.java:54)
                                                                          at com.test.test.test.util.PostListAdapter.onBindViewHolder(PostListAdapter.java:59)
                                                                          at com.test.test.test.util.PostListAdapter.onBindViewHolder(PostListAdapter.java:23)
 
    