如何与android ndk建立http连接？

#include <curl/curl.h>

int main() {
    CURL *curl;
    CURLcode res;

    curl_global_init(CURL_GLOBAL_DEFAULT);
    curl = curl_easy_init();
    if(curl) {
        curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
        res = curl_easy_perform(curl);
        if(res != CURLE_OK)
            fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
        curl_easy_cleanup(curl);
    }
    curl_global_cleanup();
    return 0;
}

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpHelper {
    public static String httpGet(String urlStr) throws Exception {
        URL url = new URL(urlStr);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("GET");
        StringBuilder response = new StringBuilder();
        BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        String inputLine;
        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();
        return response.toString();
    }
}

#include <jni.h>
#include<string>

JNIEnv *env;
jobject jobj;

extern "C" JNIEXPORT jstring JNICALL
Java_com_example_ndk_1http_MainActivity_stringFromJNI(JNIEnv *env, jobject /* this */) {
    std::string hello = "Hello from C++";
    return env->NewStringUTF(hello.c_str());
}

extern "C" JNIEXPORT void JNICALL
Java_com_example_ndk_1http_MainActivity_makeHttpRequest(JNIEnv *env, jobject /* this */, jstring url) {
    jclass cls = env->FindClass("com/example/ndk_http/HttpHelper");
    jmethodID mid = env->GetStaticMethodID(cls, "httpGet", "(Ljava/lang/String;)Ljava/lang/String;");
    jstring result = (jstring) env->CallStaticObjectMethod(cls, mid, url);
    env->DeleteLocalRef(cls);
    env->DeleteLocalRef(result);
}