Okhttp custom request body for resizing and uploading image uri

ResizeRequestBody.java

import android.content.Context;
import android.graphics.Bitmap;
import android.net.Uri;

import java.io.IOException;
import java.lang.ref.WeakReference;

import co.wardrope.android.util.BitmapResize;
import okhttp3.MediaType;
import okhttp3.RequestBody;
import okio.BufferedSink;


public class ResizeRequestBody extends RequestBody {

    private WeakReference<Context> contextRef;
    private Uri uri;
    private int minWidth;
    private int minHeight;

    public ResizeRequestBody(Context context, Uri uri, int minWidth, int minHeight) {
        this.contextRef = new WeakReference(context);
        this.uri = uri;
        this.minWidth = minWidth;
        this.minHeight = minHeight;
    }

    @Override
    public long contentLength() throws IOException {
        return -1;
    }

    @Override
    public MediaType contentType() {
        return MediaType.parse("application/octet-stream");
    }

    @Override
    public void writeTo(BufferedSink sink) throws IOException {
        try {
            Context context = contextRef.get();
            if (context != null) {
                BitmapResize.thumbnail(context, uri, minWidth, minHeight).compress(Bitmap.CompressFormat.JPEG, 75, sink.outputStream());
            }
        } finally {
            contextRef.clear();
        }
    }
}