Life without jenny

javaCode.java

String httpGet(String url) throws IOException {
    URL u = new URL(url);
    URLConnection conn = u.openConnection();
    InputStream input = conn.getInputStream();

    byte[] buffer = new byte[1024];
    int len = input.read(buffer);
    input.close();

    return new String(buffer, 0, len);
}

withJenny.cpp

jstring httpGet(jstring url) {
    jenny::LocalRef<jstring> url(_url, false);

    URLProxy url = URLProxy::newInstance(url);
    URLConnectionProxy conn = url.openConnection();
    InputStreamProxy input = conn.getInputStream();

    jenny::LocalRef<jbyteArray> buffer(env->NewByteArray(1024));
    jint len = input.read(buffer);
    input.close();

    return reinterpret_cast<jstring>(StringProxy::newInstance(env, buffer, 0, len).release);
}

withoutJenny.cpp

jstring httpGet(JNIEnv *env, jclass clazz, jstring _url) {
    jclass URLClass = env->FindClass("java/net/URL");
    jmethodID URLClass_init3 = env->GetMethodID(URLClass, "<init>", "(Ljava/lang/String;)V");
    jmethodID URLClass_openConnection =
        env->GetMethodID(URLClass, "openConnection", "()Ljava/net/URLConnection;");

    auto url = env->NewObject(URLClass, URLClass_init3, _url);
    auto conn = env->CallObjectMethod(url, URLClass_openConnection);

    jclass URLConnectionClass = env->FindClass("java/net/URLConnection");
    jmethodID URLConnectionClass_getInputStream =
        env->GetMethodID(URLConnectionClass, "getInputStream", "()Ljava/io/InputStream;");
    jclass InputStreamClass = env->FindClass("java/io/InputStream");
    jmethodID InputStreamClass_read = env->GetMethodID(InputStreamClass, "read", "([B)I");
    jmethodID InputStreamClass_close = env->GetMethodID(InputStreamClass, "close", "()V");

    auto input = env->CallObjectMethod(conn, URLConnectionClass_getInputStream);

    jbyteArray buffer = env->NewByteArray(1024);
    jint len = env->CallIntMethod(input, InputStreamClass_read, buffer);
    env->CallVoidMethod(input, InputStreamClass_close);

    jclass StringClass = env->FindClass("java/lang/String");
    jmethodID StringClass_init = env->GetMethodID(StringClass, "<init>", "([BII)V");

    jstring ret =
        reinterpret_cast<jstring>(env->NewObject(StringClass, StringClass_init, buffer, 0, len));

    env->DeleteLocalRef(URLClass);
    env->DeleteLocalRef(URLConnectionClass);
    env->DeleteLocalRef(InputStreamClass);
    env->DeleteLocalRef(StringClass);
    env->DeleteLocalRef(url);
    env->DeleteLocalRef(input);
    env->DeleteLocalRef(conn);
    env->DeleteLocalRef(buffer);

    return ret;
}