# Hintergrundtasks

Sie können Hintergrundtasks (Hintergrund-Aufgaben) definieren, die *nach* der Rückgabe einer Response ausgeführt werden sollen.

Das ist nützlich für Vorgänge, die nach einem Request ausgeführt werden müssen, bei denen der Client jedoch nicht unbedingt auf den Abschluss des Vorgangs warten muss, bevor er die Response erhält.

Hierzu zählen beispielsweise:

* E-Mail-Benachrichtigungen, die nach dem Ausführen einer Aktion gesendet werden:

          .build(),
      )
    call.execute().use { response ->
      assertThat(response.headers)
        .isEqualTo(headersOf("h1", "v1", "h2", "v2"))
      val responseBody = response.body.source()
      assertThat(responseBody.readUtf8(2)).isEqualTo("ok")
      assertThat(responseBody.exhausted()).isTrue()
      assertThat(response.trailers()).isEqualTo(headersOf("trailers", "boom"))
    }

        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

      System.out.println("Server: " + response.header("Server"));
      System.out.println("Date: " + response.header("Date"));
      System.out.println("Vary: " + response.headers("Vary"));
    }
  }

    }

    void send(final ServerMessageBlock request, final ServerMessageBlock response) throws SmbException {
        synchronized (session.transport()) {
            if (response != null) {
                response.received = false;
            }
            treeConnect(request, response);
            if (request == null || response != null && response.received) {
                return;
            }

    // The response structure is empty (0 bytes) for reconnect
    // No data is returned in a successful reconnect response

    /**
     * Create a new durable handle reconnect response
     */
    public DurableHandleReconnectResponse() {
        // No data fields for reconnect response
    }

    @Override
    public byte[] getName() {
        return CONTEXT_NAME_BYTES;
    }

    @Override

            hmac.digest(response, 0, 16);
            System.arraycopy(clientChallenge, 0, response, 16, 8);
            return response;
        } catch (final Exception ex) {
            if (LogStream.level > 0) {
                ex.printStackTrace(log);
            }
            return null;
        }
    }

    /**
     * Creates the NTLM2 response for the supplied information.
     *

  override fun satisfactionFailure(
    call: Call,
    response: Response,
  ) {
    logWithTime("satisfactionFailure")

    delegate.satisfactionFailure(call, response)
  }

  override fun cacheMiss(call: Call) {
    logWithTime("cacheMiss")

    delegate.cacheMiss(call)
  }

  override fun cacheHit(
    call: Call,
    response: Response,
  ) {
    logWithTime("cacheHit")

        }
    }

    private FileEntry advance() throws CIFSException {
        final int n =
                this.response.getStatus() == WinError.ERROR_MORE_DATA ? this.response.getNumEntries() - 1 : this.response.getNumEntries();
        while (this.ridx < n) {
            final FileEntry itm = this.response.getResults()[this.ridx];
            this.ridx++;
            if (filter(itm)) {
                return itm;
            }

///

### Before and after the `response` { #before-and-after-the-response }

You can add code to be run with the `request`,  before any *path operation* receives it.

And also after the `response` is generated, before returning it.

For example, you could add a custom header `X-Process-Time` containing the time in seconds that it took to process the request and generate a response:

            .url("https://publicobject.com/robots.txt")
            .build();

        try (Response response = client.newCall(request).execute()) {
          if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

          for (Certificate certificate : response.handshake().peerCertificates()) {
            System.out.println(CertificatePinner.pin(certificate));
          }
        }