Is there any way to download ebooks from internet to Dropbox?

I love reading novels with mobile phone and I need to go out of home constantly and stay our for a very long time, so, I need to take some ebooks with me when I was out, or I’ll die of being bored for long trip. My question is is there any way to save ebooks directly to Dropbox so I can read them on cellphone? I’m about to set out very soon, time is quite limited, plus I have to make some other preperation, just kindly help out, thanks in advance.