## Use case { #use-case }

For example, imagine that you want to return an HTTP status code of "OK" `200` by default.

But if the data didn't exist, you want to create it, and return an HTTP status code of "CREATED" `201`.

But you still want to be able to filter and convert the data you return with a `response_model`.

For those cases, you can use a `Response` parameter.

## Use a `Response` parameter { #use-a-response-parameter }

  }

  /**
   * Returns a hash function implementing the Message Authentication Code (MAC) algorithm, using the
   * MD5 (128 hash bits) hash function and a {@link SecretKeySpec} created from the given byte array
   * and the MD5 algorithm.
   *
   * <p>If you are designing a new system that needs HMAC, prefer {@link #hmacSha256} or other
   * future-proof algorithms <a

   *
   * <p><b>{@link java.nio.file.Path} equivalent:</b> {@link
   * java.nio.file.Files#createTempDirectory}.
   *
   * @return the newly-created directory
   * @throws IllegalStateException if the directory could not be created, such as if the system does
   *     not support creating temporary directories securely
   * @deprecated For Android users, see the <a

   *     expectContents(E...)} and its friends.
   */
  protected abstract Collection<E> actualContents();

  /**
   * Replaces the existing container under test with a new container created by the subject
   * generator.
   *
   * @see #resetContainer(Object) resetContainer(C)
   * @return the new container instance.
   */
  @CanIgnoreReturnValue
  protected C resetContainer() {

	//   connPool: A connection pool that provides database connections.
	//   locker: A synchronization lock that is unlocked after initialization to avoid deadlocks.
	// Returns:
	//   *Stmt: A newly created statement object for executing SQL operations.
	//   error: An error if the statement preparation fails.
	New(ctx context.Context, key string, isTransaction bool, connPool ConnPool, locker sync.Locker) (*Stmt, error)

# 响应 - 更改状态码

你可能之前已经了解到，你可以设置默认的[响应状态码](../tutorial/response-status-code.md){.internal-link target=_blank}。

但在某些情况下，你需要返回一个不同于默认值的状态码。

## 使用场景

例如，假设你想默认返回一个HTTP状态码为“OK”`200`。

但如果数据不存在，你想创建它，并返回一个HTTP状态码为“CREATED”`201`。

但你仍然希望能够使用`response_model`过滤和转换你返回的数据。

对于这些情况，你可以使用一个`Response`参数。

## 使用 `Response` 参数

你可以在你的*路径操作函数*中声明一个`Response`类型的参数（就像你可以为cookies和头部做的那样）。

然后你可以在这个*临时*响应对象中设置`status_code`。

            } else {
                return false;
            }
        }
    }

    protected final Map<Key, CacheRecord> cache = new ConcurrentHashMap<>();

    @Override
    public Key createKey(
            Plugin plugin,
            ClassLoader parentRealm,
            Map<String, ClassLoader> foreignImports,
            DependencyFilter dependencyFilter,
            List<RemoteRepository> repositories,

	create := Company{
		Name: "company_idempotent",
	}
	DB.Create(&create)

	var company Company
	if err := DB.Find(&company, "id = ?", create.ID).Error; err != nil {
		t.Fatalf("failed to find created company, got err: %v", err)
	}

	if err := DB.Save(&company).Error; err != nil || company.ID != create.ID {
		t.Errorf("failed to save company, got err: %v", err)
	}

   *
   * <p><b>{@link java.nio.file.Path} equivalent:</b> {@link
   * java.nio.file.Files#createTempDirectory}.
   *
   * @return the newly-created directory
   * @throws IllegalStateException if the directory could not be created, such as if the system does
   *     not support creating temporary directories securely
   * @deprecated For Android users, see the <a

    Entry<K, V>[] entries2 = (Entry<K, V>[]) entries;
    return copyOf(Arrays.asList(entries2));
  }

  /**
   * Returns a new builder. The generated builder is equivalent to the builder created by the {@link
   * Builder} constructor.
   */
  public static <K, V> Builder<K, V> builder() {
    return new Builder<>();
  }

  /**