在 OkHttp 拦截器中刷新令牌答案

【问题标题】：Refresh a token in OkHttp Interceptor在 OkHttp 拦截器中刷新令牌
【发布时间】：2017-02-25 08:51:42
【问题描述】：

我正在编写一个拦截器，这样当我收到 401 时，我会使用刷新令牌在后台获取新的访问令牌，然后将该令牌添加到请求中。

代码示例：

    @Override
    public Response intercept(final Chain chain) throws IOException {
        Request request = chain.request();
        Response response = chain.proceed(request);

        if (response.code() != 200) {
            try {
                new TokenRequestTask(tokenRequest, request, OkHttpresponse, chain).execute().get(5000, TimeUnit.MILLISECONDS);
                response = chain.proceed(request);
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (ExecutionException e) {
                e.printStackTrace();
            } catch (TimeoutException e) {
                e.printStackTrace();
            }
        }
        return response;
    }

在 postExecution 的异步任务中，我通过添加收到的新身份验证令牌来更改请求的标头。但问题是输出不符合预期。该函数正在返回旧响应，因为之后异步任务的结果。理想情况下，它应该等待异步任务结果然后返回但没有发生。 如何做到这一点？

【问题讨论】：

标签： android android-asynctask retrofit2 okhttp

【解决方案1】：

我正在另一个线程上为 getRefreshToken 使用 Protocol Buffer 并成功地做到了！这是我的代码：

public class IgapRetrofitInterceptor implements Interceptor {

private boolean isRefreshing;

private TokenContainer tokenContainer = TokenContainer.getInstance();

@NotNull
@Override
public Response intercept(Chain chain) throws IOException {
    Request original = chain.request();
    Request request = chain.request();

    Request.Builder builder = request.newBuilder();
    builder.header("Authorization", tokenContainer.getToken());
    builder.header("Content-Type", "application/json");
    builder.method(original.method(), original.body());

    String token = tokenContainer.getToken();

    request = builder.build();
    Response response = chain.proceed(request);

    if (response.code() == 401) {
        synchronized (this) {
            Log.e("refreshToken", "Failed " + request.toString() + " with token -> " + tokenContainer.getToken());

            String currentToken = tokenContainer.getToken();

            if (currentToken != null && currentToken.equals(token)) {
                try {
                    getRefreshToken(); //aysnc
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }

            if (tokenContainer.getToken() != null) {
                builder.header("Authorization", tokenContainer.getToken());
                request = builder.build();
                Log.e("refreshToken", "Send " + request.toString() + " again with new token -> " + tokenContainer.getToken());
                Log.e("refreshToken", "--------------------------------------------------------------------------------");
                return chain.proceed(request);
            }
        }
    }

    Log.i("refreshToken", "req 200 with token -> " + tokenContainer.getToken());

    return response;
}

public synchronized void getRefreshToken() throws InterruptedException {
    if (!isRefreshing) {

        isRefreshing = true;

        Log.e("refreshToken", "Refreshing token...");
        tokenContainer.getRefreshToken(() -> {
            synchronized (IgapRetrofitInterceptor.this) {
                isRefreshing = false;
                Log.e("refreshToken", "Proto response on success and token updated with token -> " + tokenContainer.getToken());
                IgapRetrofitInterceptor.this.notifyAll();
            }
        });
    }

    Log.e("refreshToken", "lock thread -> " + android.os.Process.getThreadPriority(android.os.Process.myTid()) + this.toString());
    this.wait();
    Log.e("refreshToken", "unlock thread -> " + android.os.Process.getThreadPriority(android.os.Process.myTid()) + this.toString());

 }
}

【讨论】：