# 额外的状态码 { #additional-status-codes }

**FastAPI** 默认使用 `JSONResponse` 返回一个响应，将你的 *路径操作* 中的返回内容放到该 `JSONResponse` 中。

**FastAPI** 会自动使用默认的状态码或者使用你在 *路径操作* 中设置的状态码。

## 额外的状态码 { #additional-status-codes_1 }

如果你想要返回主要状态码之外的状态码，你可以通过直接返回一个 `Response` 来实现，比如 `JSONResponse`，然后直接设置额外的状态码。

例如，假设你想有一个 *路径操作* 能够更新条目，并且更新成功时返回 200 「成功」 的 HTTP 状态码。

但是你也希望它能够接受新的条目。并且当这些条目不存在时，会自动创建并返回 201 「创建」的 HTTP 状态码。

    /**
     * DFS storage state indicating offline status
     */
    public static final int DFS_STORAGE_STATE_OFFLINE = 0x0001;
    /**
     * DFS storage state indicating online status
     */
    public static final int DFS_STORAGE_STATE_ONLINE = 0x0002;
    /**
     * DFS storage state indicating active status
     */
    public static final int DFS_STORAGE_STATE_ACTIVE = 0x0004;

    }

    /**
     * Returns the crawler status.
     * @return The CrawlerStatus.
     */
    public CrawlerStatus getStatus() {
        return status;
    }

    /**
     * Sets the crawler status.
     * @param status The CrawlerStatus.
     */
    public void setStatus(final CrawlerStatus status) {
        this.status = status;
    }

    /**
     * Returns the URL filter.

    //            (__)\       )\/\
    //                ||----w |
    //                ||     ||
    Runnable state = get();
    Blocker blocker = null;
    while (state instanceof Blocker || state == PARKED) {
      if (state instanceof Blocker) {
        blocker = (Blocker) state;
      }
      spinCount++;
      if (spinCount > MAX_BUSY_WAIT_SPINS) {
        /*

    assertThat(testFuture3.toString())
        .matches(
            "[^\\[]+\\[status=PENDING, setFuture=\\[[^\\[]+\\[status=PENDING,"
                + " info=\\[cause=\\[Someday...]]]]]");
    testFuture2.set("result string");
    assertThat(testFuture3.toString())
        .matches("[^\\[]+\\[status=SUCCESS, result=\\[java.lang.String@\\w+\\]\\]");
  }

  public void testToString_cancelled() throws Exception {

  static void awaitWaiting(Thread t) {
    while (true) {
      Thread.State state = t.getState();
      switch (state) {
        case RUNNABLE:
        case BLOCKED:
          Thread.yield();
          break;
        case WAITING:
          return;
        default:
          throw new AssertionError("unexpected state: " + state);
      }
    }
  }

  }

  private boolean tryToComputeNext() {
    state = State.FAILED; // temporary pessimism
    next = computeNext();
    if (state != State.DONE) {
      state = State.READY;
      return true;
    }
    return false;
  }

  @CanIgnoreReturnValue // TODO(kak): Should we remove this?
  @Override
  @ParametricNullness
  public final T next() {
    if (!hasNext()) {

  virtual absl::Status AddParameter(DataType dtype,
                                    const PartialTensorShape& shape,
                                    TracingTensorHandle**) = 0;

  // Finalize this context and make a function out of it. The context is in a
  // invalid state after this call and must be destroyed.
  virtual absl::Status Finalize(OutputList* outputs, AbstractFunction**) = 0;

        totalFailures.incrementAndGet();
        lastFailureTime.set(System.currentTimeMillis());

        State current = state.get();

        if (current == State.HALF_OPEN) {
            // Single failure in half-open state reopens the circuit
            if (state.compareAndSet(State.HALF_OPEN, State.OPEN)) {
                stateChangeTime.set(System.currentTimeMillis());
                consecutiveFailures.set(1);

 *
 * Duration duration = stopwatch.elapsed();
 *
 * log.info("time: " + stopwatch); // formatted string like "12.3 ms"
 * }
 *
 * <p>The state-changing methods are not idempotent; it is an error to start or stop a stopwatch
 * that is already in the desired state.
 *
 * <p>When testing code that uses this class, use {@link #createUnstarted(Ticker)} or {@link