Android + Picasso：如何从URL正确显示缓存中的图像

I am developing Android app now where I need to store image Url in DB for each object and then load this image from the web (if connection is on) OR get it form cache (if not). Picasso seems to be best lib for handling images in Android, so I starter using it. But I can not get how do I use it properly for my case. Even more - Images strangely are loaded into views right after they are first time get from API but if user starts app again, we can see placeholder only (even with internet connection on). Can someone suggest a solution or at least any kind of idea of best way to do this?I am developing Android app now where I need to