如何在Android中实现RESTFUL服务?

I want to ask you a question about REST web service and Android. I want to make an application which communicates with a remote database and display the values in a listview. Now, the problem at the moment is how to communicate with a remote database: I've read about REST services and I've understand they are necessary if you want to communicate with a db in a safe way, but I don't know how to make it really. My idea of this application is: I connect to a .php page placed in a remote server (using a free domain) and there i create the query to the database, so:I want to ask you a question about REST web ser