How to use the C++ REST SDK on Android (2.3+)

The easiest way to use the C++ REST SDK on android is to add the "C++ REST SDK - Android" NuGet package available via Visual Studio 2015 (including the free Community Edition). Go to Using NuGet to add the C++ REST SDK to a VS project for general information about adding NuGet packages.

After adding the package, you will need to enable exceptions, rtti, c++11, and the GNU standard library (gnustl_static). These options are all found under Configuration Properties as follows:

General -> Use of STL = gnustl_static
C++ -> Code Generation -> Enable C++ Exceptions = Unwind Tables (-funwind-tables)
C++ -> Language -> Enable Run-Time Type Information = Yes
C++ -> Language -> C++ Language Standard = C++11

Make sure you set this for all Platform/Configurations!

Finally, you will need to add some small initialization code detailed under StaticLinking. In addition to the instructions mentioned here, you can get a walkthrough with a simple sample application from this blog post.

Non-NuGet

First, follow the steps here: Setup and Build on Android

You will need to link against the following from your project:

build.armv7.debug/Binaries/libcpprest.a
Boost-for-Android/build/lib/libboost_*-clang-mt-1_55.a
libiconv/armeabi-v7a/lib/libiconv.a (removed in version 2.6.0)
openssl/armeabi-v7a/lib/libssl.a
openssl/armeabi-v7a/lib/libcrypto.a
libm (math library, link with -lm)
liblog (logging library, link with -llog)

You will also need to include the headers for boost and the C++ REST SDK:

../../Release/include
Boost-for-Android/build/include/boost-1_55

Use the included documentation with your NDK to add these prebuilt libraries and include paths. An outdated version of the relevant documentation is hosted at http://www.kandroid.org/ndk/docs/PREBUILTS.html.

Static Linking and Initialization

The C++ REST SDK prefers static linking for Android since version 2.3. This makes it much simpler for both Native Activities and Java-based Activities since there is only one shared object file in the final app bundle.

However, in order to prevent conflicts with other code, you must provide a pointer to the JVM to the SDK before it can initialize. This pointer is provided through the method cpprest_init(vm) which is located in the pplx/pplxtasks.h header file.

Note: If you do not do this, your application will terminate upon attempting to create a task.

Native Activity (android_main)

For most NativeActivity projects, if you have an entry point like

void android_main(struct android_app* state) {

You can add the following code at the top of the android_main function:

cpprest_init(state->activity->vm);

Other Shared Libraries (JNI_OnLoad)

For most shared library projects, you will simply need to copy the following code into your main cpp file:

extern "C" jint JNI_OnLoad(JavaVM* vm, void* reserved)
{
    JNIEnv* env;
    if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK)
    {
        return -1;
    }

    cpprest_init(vm);
    return JNI_VERSION_1_6;
}