In order to build these examples, add the following two rules to the top-level `WORKSPACE` file (two directories above this file):

```python
android_sdk_repository(
    name="androidsdk",
    path="<full path to your Android SDK>",
    api_level=<api level>,
    build_tools_version="<build tools version>")

android_ndk_repository(
    name="androidndk",
    path="<path to your Android NDK>",
    api_level=<api_level>)
```
For the `android_sdk_repository` rule, the values of the `api_level` and
`build_tools_version` attributes correspond, respectively, to directories
containing specific versions of the `android.jar` file and build tools. For
example, if `path=/Users/xyzzy/Library/Android/sdk`,
`api_level=21`, and `build_tools_version="21.1.1"` (note that
quotes are required in the second case), then your SDK must contain the
directories
`/Users/xyzzy/Library/Android/sdk/platforms/android-21` and
`/Users/xyzzy/Library/Android/sdk/build-tools/21.1.1`.

Similarly, for the `android_ndk_repository` rule, the value of the `api_level`
attribute corresponds to a directory containing the NDK libraries for that
API level. For example, if
`path=/Users/xyzzy/Library/Android/android-ndk-r10e` and
`api_level=21`, then you your NDK must contain the directory
`/Users/xyzzy/Library/Android/android-ndk-r10e/platforms/android-21`.

The following command can be used to build the example app:

```
bazel build //examples/android/java/bazel:hello_world
```

Yes, we know that this is a little clunky. We are working on the following things (and more):

 * Supporting other architectures than `armeabi-v7a` and compilers other than GCC 4.9
 * Eliminating the big ugly deprecation message from the console output of Bazel

We also have a nice way to speed up the edit-compile-install development cycle for physical Android devices and emulators: Bazel knows what code changed since the last build, and can use this knowledge to install only the changed code to the device. This currently works with L devices and changes to Java code and Android resources. To try this out, take an `android_binary` rule and:

 * Set the `proguard_specs` attribute to `[]` (the empty list) or just omit it altogether
 * Set the `multidex` attribute to `native`
 * Set the `dex_shards` attribute to a number between 2 and 200. This controls the size of chunks the code is split into. As this number is increased, compilation and installation becomes faster but app startup becomes slower. A good initial guess is 10.
 * Connect your device over USB to your workstation and enable USB debugging on it
 * Run `bazel mobile-install <android_binary rule>`
 * Edit Java code or Android resources
 * Run `bazel mobile-install --incremental <android_binary rule>`

Note that if you change anything other than Java code or Android resources (C++ code or something on the device), you must omit the `--incremental` command line option. Yes, we know that this is also clunky and we are working on improving it.