Compiling for Android on Android

This is more of a theoretical questions, one which I may not have thought through properly, but is it POSSIBLE to compile an Android app ON an Android de开发者_如何学编程vice? As in, write up the sourcecode on the device, compile, test and deploy it, without having to use an other OS for any part of the process?

In theory, yes. In practice, this is a lot of work. Compiling an android app involves a lot of separate tools, like the full-blown JDK, and a lot of other tools sign the resulting JAR and package it into an APK. That would have to be ported to Android, which is a major undertaking.