SSE は、HTTP 経由でサーバーからクライアントへデータをストリーミングするための標準です。

各イベントは、`data`、`event`、`id`、`retry` などの「フィールド」を含む小さなテキストブロックで、空行で区切られます。

次のようになります:

```
data: {"name": "Portal Gun", "price": 999.99}

data: {"name": "Plumbus", "price": 32.99}

```

SSE は、AI チャットのストリーミング、ライブ通知、ログやオブザビリティなど、サーバーがクライアントへ更新をプッシュする用途で一般的に使われます。

/// tip | 豆知識

例如，上述模型對應的 JSON「`object`」（或 Python `dict`）如下：

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

...由於 `description` 與 `tax` 是選填（預設為 `None`），以下這個 JSON「`object`」也有效：

```JSON
{
    "name": "Foo",
    "price": 45.2
}
```

## 將它宣告為參數 { #declare-it-as-a-parameter }

要把它加到你的*路徑操作（path operation）*中，宣告方式與路徑與查詢參數相同：

   *
   * <pre>
   * for (Foo foo : foos) {
   *   try {
   *     foo.bar();
   *   } catch (BarException | RuntimeException | Error t) {
   *     failure = t;
   *   }
   * }
   * if (failure != null) {
   *   throwIfInstanceOf(failure, BarException.class);
   *   throwIfUnchecked(failure);
   *   throw new AssertionError(failure);
   * }
   * </pre>
   *
   * @since 20.0
   */

        this.totalAllocated = new AtomicLong();
        this.totalReleased = new AtomicLong();

        // Pre-allocate buffer pool
        initializeBufferPool();
    }

    /**
     * Initialize the buffer pool with pre-allocated regions
     */
    private void initializeBufferPool() {
        // Allocate send buffers
        for (int i = 0; i < initialSendBuffers; i++) {

        }
    }

    // CHECKSTYLE_OFF: LineLength
    /**
     * <pre>&gt;&gt;&gt; mojo-artifactId:version:goal (mojo-executionId) &gt; :forked-goal @ project-artifactId &gt;&gt;&gt;</pre>
     * <pre>&gt;&gt;&gt; mojo-artifactId:version:goal (mojo-executionId) &gt; [lifecycle]phase @ project-artifactId &gt;&gt;&gt;</pre>
     */
    // CHECKSTYLE_ON: LineLength
    @Override

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


app = FastAPI()


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item, q: str | None = None):
    result = {"item_id": item_id, **item.model_dump()}
    if q:
        result.update({"q": q})

from typing import Annotated

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Annotated[Item, Body(embed=True)]):
    results = {"item_id": item_id, "item": item}

from pydantic import BaseModel, HttpUrl

app = FastAPI()


class Image(BaseModel):
    url: HttpUrl
    name: str


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None
    tags: set[str] = set()
    image: Image | None = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item):

 * for injection. It can be used to prevent unintended automatic binding of implemented
 * interfaces or extended classes.
 * <p>
 * Example usage:
 * <pre>
 * {@literal @}Typed(ServiceImpl.class)
 * public class ServiceImpl implements Service {
 *     // Implementation
 * }
 * </pre>
 *
 * @since 4.0.0
 */
@Target({FIELD, METHOD, TYPE})
@Retention(RUNTIME)
@Documented
public @interface Typed {
    /**

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


class User(BaseModel):
    username: str
    full_name: str | None = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item, user: User, importance: int = Body()):