在使用Retrofit時，有時候需要設定Set-Cookie等請求頭，如果每一個url都需要，那麼直接來個攔截器就好了.

讓所有網路請求都附上你的 token：

Interceptor mTokenInterceptor = new Interceptor() {
    @Override public Response intercept(Chain chain) throws IOException {
        Request originalRequest = chain.request();
        if (Your.sToken == null || alreadyHasAuthorizationHeader(originalRequest)) {
            return
 
 chain.proceed(originalRequest);
        }
        Request authorised = originalRequest.newBuilder()
            .header("Authorization", Your.sToken)
            .build();
        return chain.proceed(authorised);
    }
};

完整用法：

public class HttpUtils {

    private String token = null;
    private static 
 
HttpUtils self = new HttpUtils();
    private HttpUtils() {
    }

    public static HttpUtils getInstance() {
        return self;
}

    public <T> T createRequest(Class<? extends T> t) {
        Gson gson = new GsonBuilder()
                .setDateFormat("yyyy-MM-dd hh:mm:ss")
                .create();
 
Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(BaseConstant.BASE_REQUEST_URL)
                .client(genericClient())
                .addConverterFactory(ScalarsConverterFactory.create())
                .addConverterFactory(GsonConverterFactory.create(gson))
                .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
                .build();
        return retrofit.create(t);
}

    //統一攔截器
private OkHttpClient genericClient() {
        UserModel user = (UserModel) ACache.getAsObject("user");
        if (user == null) {
            token = "";
} else {
            token = user.getToken();
}
        return new OkHttpClient.Builder()
                .addInterceptor(new Interceptor() {
                    @Override
public Response intercept(Chain chain) throws IOException {
                        Request request = chain.request()
                                .newBuilder()
                                .addHeader("Authorization", token)
                                .build();
                        return chain.proceed(request);
}
                })
                .build();
}

    public MultipartBody.Part createMultipartBody(String key, String fileName, File source) {
        RequestBody file = RequestBody.create(MediaType.parse(BaseConstant.APPLICATION_OCTET_STREAM), source);
        return MultipartBody.Part.createFormData(key, fileName, file);
}
}