Learn about Java and Android development at Android Developer's Website
There are a series of tutorials and video based interactive training at Android Development Tutorials
An Oracle tutorial on Java is located at Oracle Java Tutorial
In order to develop your Java App, the following needs to be installed
In order to develop Java apps, you must install the JDK (Java Developers Kit). Many computers will have JRE (Java Runtime Environment). The JRE lets you run Java apps but doesn't support developing Java apps.
Android Studio - The Android Studio down is about 1.1 Gigabytes.
Start Android Studio. It should automatically download latest SDK. Once done, go to configure->SDK Manager. Confirm that you have Android SDK Tools 24.0.2 (or greater), Android SDK Platform Tools 21 (or greater), and Android SDK Build-tools 21.1.2 (or greater). As of Sep 10, 2015, The versions are 24.3.4, 23.0.1, and 23.0.1.
The SDK Platform and Google API's (underneath Android 5.0.1) should be installed. If not, install it. Android 6.0 (API 23) is currently available.
While the above is the most recent, the older packages have to be installed in order to work with the QualComm SDK.
Android SDK Build Tools 21.1.2
Android 4.4.2 (19)
ARM EABI v7a System Image
Intel x86 Atom System Image
Google APIs (x86 System Image)
Google APIs (ARM System Image)
In the Extras, install the Google USB Driver.
The QualComm SDK on github.
Read the FTCTraining_Manual.pdf that is the doc directory of the QualComm SDK