How to add query parameters to a HTTP GET request by OkHttp?

I finally did my code, hope the following code can help you guys. I build the URL first using

HttpUrl httpUrl = new HttpUrl.Builder()

Then pass the URL to Request requesthttp hope it helps .

public class NetActions {

    OkHttpClient client = new OkHttpClient();

    public String getStudentById(String code) throws IOException, NullPointerException {

        HttpUrl httpUrl = new HttpUrl.Builder()
                .scheme("https")
                .host("subdomain.apiweb.com")
                .addPathSegment("api")
                .addPathSegment("v1")
                .addPathSegment("students")
                .addPathSegment(code) // <- 8873 code passthru parameter on method
                .addQueryParameter("auth_token", "71x23768234hgjwqguygqew")
                // Each addPathSegment separated add a / symbol to the final url
                // finally my Full URL is: 
                // https://subdomain.apiweb.com/api/v1/students/8873?auth_token=71x23768234hgjwqguygqew
                .build();

        System.out.println(httpUrl.toString());

        Request requesthttp = new Request.Builder()
                .addHeader("accept", "application/json")
                .url(httpUrl) // <- Finally put httpUrl in here
                .build();

        Response response = client.newCall(requesthttp).execute();
        return response.body().string();
    }
}

For okhttp3:

private static final OkHttpClient client = new OkHttpClient().newBuilder()
    .connectTimeout(10, TimeUnit.SECONDS)
    .readTimeout(30, TimeUnit.SECONDS)
    .build();

public static void get(String url, Map<String,String>params, Callback responseCallback) {
    HttpUrl.Builder httpBuilder = HttpUrl.parse(url).newBuilder();
    if (params != null) {
       for(Map.Entry<String, String> param : params.entrySet()) {
           httpBuilder.addQueryParameter(param.getKey(),param.getValue());
       }
    }
    Request request = new Request.Builder().url(httpBuilder.build()).build();
    client.newCall(request).enqueue(responseCallback);
}

Here's my interceptor

    private static class AuthInterceptor implements Interceptor {

    private String mApiKey;

    public AuthInterceptor(String apiKey) {
        mApiKey = apiKey;
    }

    @Override
    public Response intercept(Chain chain) throws IOException {
        HttpUrl url = chain.request().httpUrl()
                .newBuilder()
                .addQueryParameter("api_key", mApiKey)
                .build();
        Request request = chain.request().newBuilder().url(url).build();
        return chain.proceed(request);
    }
}