void* SDL_AndroidGetJNIEnv(void)

#include "SDL.h"
#include <jni.h>

// Calls the void showHome() method of the Java instance of MyActivity.
void showHome(void)
{
    // retrieve the JNI environment.
    JNIEnv* env = (JNIEnv*)SDL_AndroidGetJNIEnv();

    // retrieve the Java instance of the SDLActivity
    jobject activity = (jobject)SDL_AndroidGetActivity();

    // find the Java class of the activity. It should be SDLActivity or a subclass of it.
    jclass clazz(env->GetObjectClass(activity));

    // find the identifier of the method to call
    jmethodID method_id = env->GetMethodID(clazz, "showHome", "()V");

    // effectively call the Java method
    env->CallVoidMethod(activity, method_id);

    // clean up the local references.
    env->DeleteLocalRef(activity);
    env->DeleteLocalRef(clazz);
}