Question

在使用Client配置泽西ApacheConnector时，我遇到了问题。它似乎忽略了我在WriterInterceptor中定义的所有请求标头。我可以告诉我在WriterInterceptor内设置断点时会调用WriterInterceptor#aroundWriteTo(WriterInterceptorContext)。与此相反，我可以观察到InputStream的修改被保留。

这是一个展示我问题的可运行示例：

public class ApacheConnectorProblemDemonstration extends JerseyTest {

  private static final Logger LOGGER = Logger.getLogger(JerseyTest.class.getName());
  private static final String QUESTION = "baz", ANSWER = "qux";
  private static final String REQUEST_HEADER_NAME_CLIENT = "foo-cl", REQUEST_HEADER_VALUE_CLIENT = "bar-cl";
  private static final String REQUEST_HEADER_NAME_INTERCEPTOR = "foo-ic", REQUEST_HEADER_VALUE_INTERCEPTOR = "bar-ic";
  private static final int MAX_CONNECTIONS = 100;
  private static final String PATH = "/";

  @Path(PATH)
  public static class TestResource {
    @POST
    public String handle(InputStream questionStream,
                         @HeaderParam(REQUEST_HEADER_NAME_CLIENT) String client,
                         @HeaderParam(REQUEST_HEADER_NAME_INTERCEPTOR) String interceptor) 
        throws IOException {
      assertEquals(REQUEST_HEADER_VALUE_CLIENT, client);
      // Here, the header that was set in the client's writer interceptor is lost.
      assertEquals(REQUEST_HEADER_VALUE_INTERCEPTOR, interceptor);
      // However, the input stream got gzipped so the WriterInterceptor has been partly applied.
      assertEquals(QUESTION, new Scanner(new GZIPInputStream(questionStream)).nextLine());
      return ANSWER;
    }
  }

  @Provider
  @Priority(Priorities.ENTITY_CODER)
  public static class ClientInterceptor implements WriterInterceptor {
    @Override
    public void aroundWriteTo(WriterInterceptorContext context) 
        throws IOException, WebApplicationException {
      context.getHeaders().add(REQUEST_HEADER_NAME_INTERCEPTOR, REQUEST_HEADER_VALUE_INTERCEPTOR);
      context.setOutputStream(new GZIPOutputStream(context.getOutputStream()));
      context.proceed();
    }
  }

  @Override
  protected Application configure() {
    enable(TestProperties.LOG_TRAFFIC);
    enable(TestProperties.DUMP_ENTITY);
    return new ResourceConfig(TestResource.class);
  }

  @Override
  protected Client getClient(TestContainer tc, ApplicationHandler applicationHandler) {
    ClientConfig clientConfig = tc.getClientConfig() == null ? new ClientConfig() : tc.getClientConfig();
    clientConfig.property(ApacheClientProperties.CONNECTION_MANAGER, makeConnectionManager(MAX_CONNECTIONS));
    clientConfig.register(ClientInterceptor.class);
    // If I do not use the Apache connector, I avoid this problem.
    clientConfig.connector(new ApacheConnector(clientConfig));
    if (isEnabled(TestProperties.LOG_TRAFFIC)) {
      clientConfig.register(new LoggingFilter(LOGGER, isEnabled(TestProperties.DUMP_ENTITY)));
    }
    configureClient(clientConfig);
    return ClientBuilder.newClient(clientConfig);
  }

  private static ClientConnectionManager makeConnectionManager(int maxConnections) {
    PoolingClientConnectionManager connectionManager = new PoolingClientConnectionManager();
    connectionManager.setMaxTotal(maxConnections);
    connectionManager.setDefaultMaxPerRoute(maxConnections);
    return connectionManager;
  }

  @Test
  public void testInterceptors() throws Exception {
    Response response = target(PATH)
        .request()
        .header(REQUEST_HEADER_NAME_CLIENT, REQUEST_HEADER_VALUE_CLIENT)
        .post(Entity.text(QUESTION));
    assertEquals(200, response.getStatus());
    assertEquals(ANSWER, response.readEntity(String.class));
  }
}

我想使用ApacheConnector来优化PoolingClientConnectionManager的并发请求。我搞砸了配置吗？

PS：使用GrizzlyConnector时会出现完全相同的问题。

Answer 1

经过进一步研究，我认为这是使用Connector的默认HttpURLConnection中的错误行为。正如我在other self-answered question中所解释的那样documentation states：

而过滤器主要用于操纵请求和响应参数，如HTTP头，URI和/或HTTP方法，拦截器旨在通过操纵来操纵实体实体输入/输出流

WriterInterceptor不应该操纵标题值，而{Client,Server}RequestFilter不应该操纵实体流。如果您需要同时使用这两个组件，则两个组件应捆绑在javax.ws.rs.core.Feature内或在实现两个接口的同一个类中。（如果你需要设置两个不同的Priority，这可能会有问题。）

所有这一切都非常不幸，因为JerseyTest使用了使用Connector的{{1}}，以便我的所有单元测试成功，而现实生活中的应用程序由于配置了HttpURLConnection。而且，我希望泽西岛能给我一些例外，而不是压制变化。（这是我与泽西岛的一般性问题。例如，当我使用太新版本的ApacheConnector时，界面被重命名为ClientConnectionManager我只是被告知一行日志语句，我的所有配置工作都被忽略。我没有发现这个日志语句直到开发很晚。）

ApacheConnector不处理在WriterInterceptor中设置的请求标头

1 个答案: