问如何通过NDK使用c代码检查运行API级别的设备？

EN

static const char* TAG = "testjnjni";

static bool _disableHttpKeepAliveOnBuggyPlatforms(JNIEnv *env)
{
    // Based on article here:
    //   http://android-developers.blogspot.co.uk/2011/09/androids-http-clients.html
    // Which references the issue documented here:
    //   http://code.google.com/p/android/issues/detail?id=2939
    // We need to set "http.keepAlive" to "false" if running an OS version earlier than Froyo (API Level 8)

    if ((*env)->ExceptionCheck(env))
        return false; // already got an exception pending

    bool success = true;

    // VERSION is a nested class within android.os.Build (hence "$" rather than "/")
    jclass versionClass = (*env)->FindClass(env, "android/os/Build$VERSION");
    if (NULL == versionClass)
        success = false;

    jfieldID sdkIntFieldID = NULL;
    if (success)
        success = (NULL != (sdkIntFieldID = (*env)->GetStaticFieldID(env, versionClass, "SDK_INT", "I")));

    jint sdkInt = 0;
    if (success)
    {
        sdkInt = (*env)->GetStaticIntField(env, versionClass, sdkIntFieldID);
        __android_log_print(ANDROID_LOG_VERBOSE, TAG, "sdkInt = %d", sdkInt);
    }

    if (success && sdkInt < 8)
    {
        jclass systemClass = (*env)->FindClass(env, "java/lang/System");
        if (NULL == systemClass)
            success = false;

        jmethodID setPropertyMethodID = NULL;
        if (success)
            success = (NULL != (setPropertyMethodID = (*env)->GetStaticMethodID(env, systemClass, "setProperty", "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;")));

        jstring propString = NULL;
        if (success)
            success = (NULL != (propString = (*env)->NewStringUTF(env, "http.keepAlive")));

        jstring valueString = NULL;
        if (success)
            success = (NULL != (valueString = (*env)->NewStringUTF(env, "false")));

        jobject oldValueString = NULL;
        if (success)
        {
            __android_log_print(ANDROID_LOG_VERBOSE, TAG, "Disabling http.keepAlive");
             oldValueString = (*env)->CallStaticObjectMethod(env, systemClass, setPropertyMethodID, propString, valueString);
        }

        // cleanup
        (*env)->DeleteLocalRef(env, propString);
        (*env)->DeleteLocalRef(env, valueString);
        (*env)->DeleteLocalRef(env, oldValueString);
        (*env)->DeleteLocalRef(env, systemClass);
    }

    // cleanup
    (*env)->DeleteLocalRef(env, versionClass);

    return success;
}