RetrofitHelper 工具类

public class RetrofitHelper {
    private static OkHttpClient okHttpClient;
    private static HttpUtils httpUtils;

    static {
        initOkHttpClient();
    }

    /**
     * 初始化OkHttpClient
     */
    private static void initOkHttpClient() {
        if (okHttpClient == null) {
            synchronized (RetrofitHelper.class) {
                if (okHttpClient == null) {
                    HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
                    logging.setLevel(HttpLoggingInterceptor.Level.BODY);
                    okHttpClient = new OkHttpClient.Builder()
                            .addInterceptor(logging)
.addInterceptor(new MyInterceptor())
.build();
                }
            }
        }
    }

    /**
     * 定义一个泛型方法
     *
     * @param tClass
     * @param url
     * @param <T>
     * @return
     */
    public static <T> T createAPI(Class<T> tClass, String url) {
        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(url)
                .client(okHttpClient)
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .build();
        return retrofit.create(tClass);
    }

    public static HttpUtils getHttpUtils() {
        if (httpUtils == null) {
            synchronized (HttpUtils.class) {
                if (httpUtils == null) {
                    httpUtils = createAPI(HttpUtils.class, API.HOST);
                }
            }
        }
        return httpUtils;
    }
/**
 * 添加公共参数拦截器
 */
static class MyInterceptor implements Interceptor {

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

public class RetrofitHelper {
    private static Retrofit retrofit;

    private static ServiceApi serviceApi;

    /**
     * 初始化Retrofit 单例模式
     */
    private static Retrofit getRetrofit() {
        //线程安全
        if (retrofit == null) {
            synchronized (RetrofitHelper.class) {
                if (retrofit == null) {
                    //设置拦截器
                    HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
                    logging.setLevel(HttpLoggingInterceptor.Level.BODY);
                    OkHttpClient client = new OkHttpClient.Builder()
                            .addInterceptor(new MyInterceptor())
                            .addInterceptor(logging)//添加拦截器
                            .connectTimeout(5, TimeUnit.SECONDS)//设置连接超时
                            .build();


                    retrofit = new Retrofit.Builder()
                            .baseUrl(UrlsApi.BASE_URL)
                            .client(client)
                            .addConverterFactory(GsonConverterFactory.create())
                            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                            .build();
                }
            }
        }

        return retrofit;
    }


    public static ServiceApi getServiceApi() {
        if (serviceApi == null) {
            synchronized (RetrofitHelper.class) {
                if (serviceApi == null) {
                    serviceApi = getRetrofit().create(ServiceApi.class);
                }
            }
        }
        return serviceApi;
    }

    /**
     * 添加公共参数拦截器
     */
    static class MyInterceptor implements Interceptor {
        @Override
        public Response intercept(Chain chain) throws IOException {
            Request request = chain.request();
            HttpUrl httpUrl = request
                    .url()
                    .newBuilder()
                    .addQueryParameter("source", "android")
                    .build();
            Request requestNew = request
                    .newBuilder()
                    .url(httpUrl)
                    .build();
            return chain.proceed(requestNew);
        }
    }
}