经过长时间的研究，我自定义Apache客户端来处理刷新AccessToken For Retrofit，其中您发送访问令牌作为参数。

使用cookie持久客户端启动适配器

restAdapter = new RestAdapter.Builder()
                .setEndpoint(SERVER_END_POINT)
                .setClient(new CookiePersistingClient())
                .setLogLevel(RestAdapter.LogLevel.FULL).build();

Cookie持久客户端，为所有请求维护Cookie，并检查每个请求响应，如果是未经授权的访问ERROR_CODE = 401，刷新访问令牌并召回请求，否则仅处理请求。

private static class CookiePersistingClient extends ApacheClient {

    private static final int HTTPS_PORT = 443;
    private static final int SOCKET_TIMEOUT = 300000;
    private static final int CONNECTION_TIMEOUT = 300000;

    public CookiePersistingClient() {
        super(createDefaultClient());
    }

    private static HttpClient createDefaultClient() {
        // Registering https clients.
        SSLSocketFactory sf = null;
        try {
            KeyStore trustStore = KeyStore.getInstance(KeyStore
                    .getDefaultType());
            trustStore.load(null, null);

            sf = new MySSLSocketFactory(trustStore);
            sf.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
        } catch (KeyManagementException e) {
            e.printStackTrace();
        } catch (UnrecoverableKeyException e) {
            e.printStackTrace();
        } catch (KeyStoreException e) {
            e.printStackTrace();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (CertificateException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        HttpParams params = new BasicHttpParams();
        HttpConnectionParams.setConnectionTimeout(params,
                CONNECTION_TIMEOUT);
        HttpConnectionParams.setSoTimeout(params, SOCKET_TIMEOUT);
        SchemeRegistry registry = new SchemeRegistry();
        registry.register(new Scheme("https", sf, HTTPS_PORT));
        // More customization (https / timeouts etc) can go here...

        ClientConnectionManager cm = new ThreadSafeClientConnManager(
                params, registry);
        DefaultHttpClient client = new DefaultHttpClient(cm, params);

        // Set the default cookie store
        client.setCookieStore(COOKIE_STORE);

        return client;
    }

    @Override
    protected HttpResponse execute(final HttpClient client,
            final HttpUriRequest request) throws IOException {
        // Set the http context's cookie storage
        BasicHttpContext mHttpContext = new BasicHttpContext();
        mHttpContext.setAttribute(ClientContext.COOKIE_STORE, COOKIE_STORE);
        return client.execute(request, mHttpContext);
    }

    @Override
    public Response execute(final Request request) throws IOException {
        Response response = super.execute(request);
        if (response.getStatus() == 401) {

            // Retrofit Callback to handle AccessToken
            Callback<AccessTockenResponse> accessTokenCallback = new Callback<AccessTockenResponse>() {

                @SuppressWarnings("deprecation")
                @Override
                public void success(
                        AccessTockenResponse loginEntityResponse,
                        Response response) {
                    try {
                        String accessToken =  loginEntityResponse
                                .getAccessToken();
                        TypedOutput body = request.getBody();
                        ByteArrayOutputStream byte1 = new ByteArrayOutputStream();
                        body.writeTo(byte1);
                        String s = byte1.toString();
                        FormUrlEncodedTypedOutput output = new FormUrlEncodedTypedOutput();
                        String[] pairs = s.split("&");
                        for (String pair : pairs) {
                            int idx = pair.indexOf("=");
                            if (URLDecoder.decode(pair.substring(0, idx))
                                    .equals("access_token")) {
                                output.addField("access_token",
                                        accessToken);
                            } else {
                                output.addField(URLDecoder.decode(
                                        pair.substring(0, idx), "UTF-8"),
                                        URLDecoder.decode(
                                                pair.substring(idx + 1),
                                                "UTF-8"));
                            }
                        }
                        execute(new Request(request.getMethod(),
                                request.getUrl(), request.getHeaders(),
                                output));
                    } catch (IOException e) {
                        e.printStackTrace();
                    }

                }

                @Override
                public void failure(RetrofitError error) {
                    // Handle Error while refreshing access_token
                }
            };
            // Call Your retrofit method to refresh ACCESS_TOKEN
            refreshAccessToken(GRANT_REFRESH,CLIENT_ID, CLIENT_SECRET_KEY,accessToken, accessTokenCallback);
        }

        return response;
    }
}

我知道这是一条老帖子，但以防有人无意中发现。

TokenAuthenticator依赖于服务类。服务类依赖于OkHttpClient实例。要创建OkHttpClient，我需要TokenAuthenticator。我该如何打破这个循环?两个不同的OkHttpClients?它们将有不同的连接池..

我也面临着同样的问题,但我想只创建一个OkHttpClient因为我不认为我需要另一个TokenAuthenticator本身,我用Dagger2,所以我最终提供服务类TokenAuthenticator懒惰的注入,你可以阅读更多关于懒惰匕首2中注入,但基本上就像说匕首TokenAuthenticator所需的不去创建服务。

你可以参考这个SO线程的示例代码:如何解决一个循环依赖，同时仍然使用Dagger2?

给任何人谁想解决并发/并行调用时刷新令牌。这里有一个变通办法

class TokenAuthenticator: Authenticator {

    override fun authenticate(route: Route?, response: Response?): Request? {
        response?.let {
            if (response.code() == 401) {
                while (true) {
                    if (!isRefreshing) {
                        val requestToken = response.request().header(AuthorisationInterceptor.AUTHORISATION)
                        val currentToken = OkHttpUtil.headerBuilder(UserService.instance.token)

                        currentToken?.let {
                            if (requestToken != currentToken) {
                                return generateRequest(response, currentToken)
                            }
                        }

                        val token = refreshToken()
                        token?.let {
                            return generateRequest(response, token)
                        }
                    }
                }
            }
        }

        return null
    }

    private fun generateRequest(response: Response, token: String): Request? {
        return response.request().newBuilder()
                .header(AuthorisationInterceptor.USER_AGENT, OkHttpUtil.UA)
                .header(AuthorisationInterceptor.AUTHORISATION, token)
                .build()
    }

    private fun refreshToken(): String? {
        synchronized(TokenAuthenticator::class.java) {
            UserService.instance.token?.let {
                isRefreshing = true

                val call = ApiHelper.refreshToken()
                val token = call.execute().body()
                UserService.instance.setToken(token, false)

                isRefreshing = false

                return OkHttpUtil.headerBuilder(token)
            }
        }

        return null
    }

    companion object {
        var isRefreshing = false
    }
}

使用一个拦截器(注入令牌)和一个验证器(刷新操作)完成工作，但是:

我也有一个双重呼叫的问题:第一个呼叫总是返回401: 在第一次调用(拦截器)时没有注入令牌，并且调用验证器:发出了两个请求。

修复只是在拦截器中重新影响对构建的请求:

之前:

private Interceptor getInterceptor() {
    return (chain) -> {
        Request request = chain.request();
        //...
        request.newBuilder()
                .header(AUTHORIZATION, token))
                .build();
        return chain.proceed(request);
    };
}

后:

private Interceptor getInterceptor() {
    return (chain) -> {
        Request request = chain.request();
        //...
        request = request.newBuilder()
                .header(AUTHORIZATION, token))
                .build();
        return chain.proceed(request);
    };
}

在一个街区:

private Interceptor getInterceptor() {
    return (chain) -> {
        Request request = chain.request().newBuilder()
                .header(AUTHORIZATION, token))
                .build();
        return chain.proceed(request);
    };
}

希望能有所帮助。

编辑:我没有找到一种方法来避免第一次调用总是返回401，只使用验证器而不使用拦截器

请不要使用拦截器来处理身份验证。

目前，处理身份验证的最佳方法是使用新的Authenticator API，它是专门为此目的设计的。

当响应为401未授权重试最后一次失败的请求时，OkHttp将自动向验证者请求凭据。

public class TokenAuthenticator implements Authenticator {
    @Override
    public Request authenticate(Proxy proxy, Response response) throws IOException {
        // Refresh your access_token using a synchronous api request
        newAccessToken = service.refreshToken();

        // Add new header to rejected request and retry it
        return response.request().newBuilder()
                .header(AUTHORIZATION, newAccessToken)
                .build();
    }

    @Override
    public Request authenticateProxy(Proxy proxy, Response response) throws IOException {
        // Null indicates no attempt to authenticate.
        return null;
    }

将验证器附加到OkHttpClient，方法与拦截器相同

OkHttpClient okHttpClient = new OkHttpClient();
okHttpClient.setAuthenticator(authAuthenticator);

在创建您的Retrofit RestAdapter时使用此客户端

RestAdapter restAdapter = new RestAdapter.Builder()
                .setEndpoint(ENDPOINT)
                .setClient(new OkClient(okHttpClient))
                .build();
return restAdapter.create(API.class);

正如Brais Gabin在评论中所说，我遇到了TokenAuthenticator依赖于服务类的问题。服务类依赖于OkHttpClient实例，要创建OkHttpClient，我需要TokenAuthenticator。

那么我是如何打破这个循环的呢?

我创建了一个新的okHttpClient对象，一个新的Retrofit对象，并使用该对象调用refreshToken来获得新的令牌(检查getUpdatedToken()函数)

class TokenAuthenticator : Authenticator {

    override fun authenticate(route: Route?, response: Response): Request? {
        return runBlocking {

            // 1. Refresh your access_token using a synchronous api request
           val response = getUpdatedToken(refreshToken)

           //2. In my case here I store the new token and refreshToken into SharedPreferences

           response.request.newBuilder()
                        .header("Authorization", "Bearer   ${tokenResponse.data?.accessToken}")
                        .build()

           // 3. If there's any kind of error I return null
           
        }
    }

    private suspend fun getUpdatedToken( refreshToken: String): TokenResponse {
        val okHttpClient = OkHttpClient().newBuilder()
            .addInterceptor(errorResponseInterceptor)
            .build()

        val retrofit = Retrofit.Builder()
            .baseUrl(BuildConfig.BASE_URL)
            .client(okHttpClient)
            .addConverterFactory(MoshiConverterFactory.create())
            .build()


        val service = retrofit.create(RefreshTokenApi::class.java)
        return service.refreshToken(refreshToken)

    }

}

RefreshTokenApi

interface RefreshTokenApi {

    @FormUrlEncoded
    @POST("refreshToken")
    suspend fun refreshToken(
        @Field("refresh_token") refreshToeken: String
    ): TokenResponse
}

在这个项目中，我使用Koin，我这样配置:

object RetrofigConfig {
    fun provideRetrofit(okHttpClient: OkHttpClient): Retrofit {
        return Retrofit.Builder()
            .baseUrl(BuildConfig.BASE_URL)
            .client(okHttpClient)
            .addConverterFactory(MoshiConverterFactory.create())
            .build()
    }

    fun provideOkHttpClient(
        tokenAuthenticator: TokenAuthenticator
    ): OkHttpClient {

        return OkHttpClient().newBuilder()
            .authenticator(tokenAuthenticator)
            .build()
    }

    fun provideServiceApi(retrofit: Retrofit): ServiceApi {
        return retrofit.create(ServiceApi::class.java)
    }
}

重要的一行是OkHttpClient().newBuilder().authenticator(tokenAuthenticator)

因为这是我第一次实现这个，我不知道这是否是最好的方式，但这是它在我的项目中工作的方式。