如何在 okhttp 中更改请求的超时时间

How to change timeout for a request in okhttp

通常我们为 okHttp 客户端设置超时,并且我们使用该客户端的单个实例。因此,一旦客户端生成,我们就无法更改该客户端的超时时间。

如何更改特定请求的超时时间??到底有没有 在不创建新客户的情况下做到这一点??

很常见的是,某些调用花费的时间至少是每个应用程序的 1/2,这需要比其他应用程序更多的超时。如果请求可以覆盖默认超时,那就太好了。

请参阅 https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PerCallSettings.java,它创建仅修改某些设置的浅层克隆。

// Copy to customize OkHttp for this request.
OkHttpClient client2 = client.newBuilder()
    .readTimeout(3000, TimeUnit.MILLISECONDS)
    .build();

在 3.9 中,可以在拦截器中针对每个请求进行设置

https://github.com/square/okhttp/blob/36bd68aa3e93affb12504cd40454e64c6812019c/okhttp-tests/src/test/java/okhttp3/InterceptorTest.java#L747-L757

  @Test public void chainWithReadTimeout() throws Exception {
    Interceptor interceptor1 = new Interceptor() {
      @Override public Response intercept(Chain chainA) throws IOException {
        assertEquals(5000, chainA.readTimeoutMillis());

        Chain chainB = chainA.withReadTimeout(100, TimeUnit.MILLISECONDS);
        assertEquals(100, chainB.readTimeoutMillis());

        return chainB.proceed(chainA.request());
      }
    };
  }

更新到 Retrofit 2.5.0 您可以使用 Invocation class

New: Invocation class provides a reference to the invoked method and argument list as a tag on the underlying OkHttp Call. This can be accessed from an OkHttp interceptor for things like logging, analytics, or metrics aggregation.

这样,您可以创建一个 SpecificTimeout 注释,仅用于您需要设置不同超时持续时间的请求,并在 OkHttp Interceptor 上读取其值以更改超时时间那一点。

自定义注释

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface SpecificTimeout {
    int duration();
    TimeUnit unit();
}

服务接口

public interface GitHubService {
    @GET("/users")
    @SpecificTimeout(duration = 5000, unit = TimeUnit.MILLISECONDS)
    Call<List<User>> listUsers();

    @GET("/repos")
    @SpecificTimeout(duration = 15000, unit = TimeUnit.MILLISECONDS)
    Call<List<Repo>> listRepos();
}

拦截器

class TimeoutInterceptor implements Interceptor {

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

        final Invocation tag = request.tag(Invocation.class);
        final Method method = tag != null ? tag.method() : null;
        final SpecificTimeout timeout = method != null ? method.getAnnotation(SpecificTimeout.class) : null;

        if (timeout != null) {
           return chain.withReadTimeout(timeout.duration(), timeout.unit())
                       .withConnectTimeout(timeout.duration(), timeout.unit())
                       .withWriteTimeout(timeout.duration(), timeout.unit())
                       .proceed(request);
        }

        return chain.proceed(request);
    }
}

OkHttp 生成器

OkHttpClient okHttpClient = new OkHttpClient.Builder()
                //default timeout for not annotated requests
                .readTimeout(10000, TimeUnit.MILLISECONDS)
                .connectTimeout(10000, TimeUnit.MILLISECONDS)
                .writeTimeout(10000, TimeUnit.MILLISECONDS)
                .addInterceptor(new TimeoutInterceptor())
                .build();

我认为一个好方法是在拦截器上读取自定义 header 并将当前超时更改为包含此特定 header 的调用,它比创建注释和使用反射效果更好阅读它。例如:

class TimeoutInterceptor : Interceptor {

    override fun intercept(chain: Interceptor.Chain): Response {
        val request = chain.request()

        return request.header("Custom-Timeout")?.let {
            val newTimeout = it.toInt()
            chain.withReadTimeout(newTimeout, TimeUnit.MILLISECONDS)
                .withConnectTimeout(newTimeout, TimeUnit.MILLISECONDS)
                .withWriteTimeout(newTimeout, TimeUnit.MILLISECONDS)
                .proceed(request)
        } ?: chain.proceed(request)
    }
}