有没有办法使用 Retrofit 2 向每个请求添加查询参数？

Question

我需要为 Retrofit 2.0.0-beta2 库发出的每个请求添加一个查询参数。我为 Retrofit 1.9 找到了this solution，但是如何在最新的库版本中添加RequestInterceptor？

我的界面：

@GET("user/{id}")
Call<User> getUser(@Path("id")long id);

@GET("users/")
Call<List<User>> getUser();

客户：

Retrofit retrofit = new Retrofit.Builder()
                    .baseUrl(BASE_URL)
                    .addConverterFactory(GsonConverterFactory.create())
                    .client(CLIENT)  // custom OkHTTP Client
                    .build();
service = retrofit.create(userService.class);

Answer 1

为了完整起见，这里是您需要使用 OkHttp-Interceptor 为每个 Retrofit 2.x 请求添加参数的完整代码：

OkHttpClient client = new OkHttpClient();

client.interceptors().add(new Interceptor() {
    @Override
    public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();
        HttpUrl url = request.url().newBuilder().addQueryParameter("name","value").build();
        request = request.newBuilder().url(url).build();
        return chain.proceed(request);
    }
});

Retrofit retrofit = new Retrofit.Builder()
        .baseUrl("...")
        .client(client)
        .build();

Answer 2

现在改造已发布 2.0.0，这是我的解决方案：

OkHttpClient client = new OkHttpClient.Builder()
        .addInterceptor(new Interceptor() {
            @Override
            public Response intercept(Chain chain) throws IOException {

                String uid = "0";
                long timestamp = (int) (Calendar.getInstance().getTimeInMillis() / 1000);
                String signature = MD5Util.crypt(timestamp + "" + uid + MD5_SIGN);
                String base64encode = signature + ":" + timestamp + ":" + uid;
                base64encode = Base64.encodeToString(base64encode.getBytes(), Base64.NO_WRAP | Base64.URL_SAFE);

                Request request = chain.request();
                HttpUrl url = request.url()
                        .newBuilder()
                        .addQueryParameter("pageSize", "2")
                        .addQueryParameter("method", "getAliasList")
                        .build();

                request = request
                        .newBuilder()
                        .addHeader("Authorization", "zui " + base64encode)
                        .addHeader("from_client", "ZuiDeer")
                        .url(url)
                        .build();

                Response response = chain.proceed(request);
                return response;
            }
        }).build();


Retrofit retrofit = new Retrofit.Builder()
        .baseUrl(ApiConstants.API_BASE_URL)
        .client(client)
        .addConverterFactory(GsonConverterFactory.create())
        .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
        .build();

mRestfulService = retrofit.create(RestfulService.class);

Answer 3

在3.2.0 及更高版本中，您应该在OkHttpClient.Builder 中使用addInterceptor()。

例如，Retrolambda:

HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor()
        .setLevel(HttpLoggingInterceptor.Level.BASIC);

Interceptor clientInterceptor = chain -> {
    Request request = chain.request();
    HttpUrl url = request.url().newBuilder().addQueryParameter("name", "value").build();
    request = request.newBuilder().url(url).build();
    return chain.proceed(request);
};

OkHttpClient client = new OkHttpClient.Builder()
        .addNetworkInterceptor(clientInterceptor)
        .addInterceptor(loggingInterceptor)
        .build();

Retrofit retrofit = new Retrofit.Builder()
        .baseUrl(BASE_URL)
        .addConverterFactory(GsonConverterFactory.create())
        .client(client)
        .build();

Answer 4

您必须从OkHttp 切换到Interceptor。创建一个OkHttpClient，将Interceptor 添加到它，并在Retrofit Builder 中传递该客户端。

OkHttpClient client = new OkHttpClient();
client.interceptors().add(new Interceptor() {
    @Override
    public Response intercept(Chain chain) throws IOException {
        ...
    }
});

Retrofit retrofit = new Retrofit.Builder()
        .baseUrl("...")
        .client(client)
        .build();

然后，您可以使用 chain.request().newBuilder() 根据您的需要调整请求。详情请见documentation。

Answer 5

在 kotlin 中，将以下拦截器添加到您在 Retrofit builder 中设置的 OkHttpClient ：

Retrofit.Builder()
    .baseUrl("...")
    .client(
        OkHttpClient.Builder()
            .addInterceptor { chain ->
                val url = chain
                    .request()
                    .url()
                    .newBuilder()
                    .addQueryParameter("key", "value")
                    .build()
                chain.proceed(chain.request().newBuilder().url(url).build())
            }
            .build()
    )
    .build()
    .create(FooService::class.java)

当然，将 OkHttpClient 构建提取到 val 或注入依赖项中会使其更加模块化和易读。

Answer 6

很多这些答案都是相似的，但我遇到的一个问题是 Interceptor 内的函数链接导致它失败。根据链接的视频更改cannot be made directly to a url。相反，必须制作 url 的副本，然后重新分配回原始 url，如下所示：

{

public method(){
    final String api_key = "key";

    OkHttpClient client = new OkHttpClient.Builder()
                          .addInterceptor(new Interceptor() {
                              @Override
                              public Response intercept(Chain chain) throws IOException {
                                    Request original = chain.request();
                                    HttpUrl httpUrl = original.url();

                                    HttpUrl newHttpUrl = httpUrl
                                                        .newBuilder()
                                                        .addQueryParameter("api_key", api_key)
                                                        .build();

                                    Request.Builder requestBuilder = original
                                                                 .newBuilder()
                                                             .url(newHttpUrl);

                                    Request request = requestBuilder
                                                      .build();
                                    return chain.proceed(request);
                              }
                          }).build();


    retrofit = new Retrofit.Builder()
            .baseUrl("https://base.url.ext/")
            .client(client)
            .addConverterFactory(GsonConverterFactory.create())
            .build();
}

虽然调用的函数与第一个答案相同，但此答案对函数调用进行了分区。即，原始 url 和新 url 存储在单独的局部变量中。这可以防止覆盖原始 url，直到您希望 OkHttpClient 这样做。

Answer 7

对于更简洁的代码方法，为拦截器链设置一个单独的类，如下所示：

    public class LanguageInterceptor implements Interceptor {
        @Override
        public Response intercept(Chain chain) throws IOException {
            HttpUrl url = chain.request()
                    .url()
                    .newBuilder()
                    .addQueryParameter("name","value")
                    .build();

            Request request = chain.request()
                    .newBuilder()
                    .url(url)
                    .build();
            Response response = chain.proceed(request);
            return response;
        }
    }

然后在定义改造实例的类中，使用.addInterceptor(new LanguageInterceptor()) 向其中添加实例对象，如下所示：

public static Retrofit getClient() {
        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
        OkHttpClient client = new OkHttpClient.Builder()
                .connectTimeout(30, TimeUnit.SECONDS)
                .readTimeout(30, TimeUnit.SECONDS)
                .addInterceptor(new LanguageInterceptor())
                .addInterceptor(interceptor)
                .build();

        if (retrofit == null) {
            retrofit = new Retrofit.Builder()
                    .baseUrl(BASE_URL)
                    .client(client)
                    .addConverterFactory(ScalarsConverterFactory.create())
                    .addConverterFactory(GsonConverterFactory.create())
                    .build();
            Log.e(TAG, "getClient: base url " + retrofit.baseUrl());
        }
        return retrofit;
    }