ErrHandlerAlreadyExists = errors.New("mux handler already exists")

	// ErrIncorrectSequence is returned when an out-of-sequence item is received.
	ErrIncorrectSequence = errors.New("out-of-sequence item received")
)

// ErrResponse is a remote error response.
type ErrResponse struct {
	msg string
}

func (e ErrResponse) Error() string {

在介绍依赖项与安全的章节中，您可以了解更多用 `raise` 异常代替 `return` 值的优势。

本例中，客户端用 `ID` 请求的 `item` 不存在时，触发状态码为 `404` 的异常：

```Python hl_lines="11"
{!../../docs_src/handling_errors/tutorial001.py!}

```

### 响应结果

请求为 `http://example.com/items/foo`（`item_id` 为 `「foo」`）时，客户端会接收到 HTTP 状态码 - 200 及如下 JSON 响应结果：

```JSON
{
  "item": "The Foo Wrestlers"
}

```

                        },
                    },
                    "summary": "Read User Item",
                    "operationId": "read_user_item_items__item_id__get",
                    "parameters": [
                        {
                            "required": True,
                            "schema": {"title": "Item Id", "type": "string"},
                            "name": "item_id",

    public abstract PagingList<T> selectList(int offset, int size);

    public abstract OptionalEntity<T> get(long id);

    public abstract void insert(T item);

    public abstract void update(T item);

    public abstract void delete(T item);

    public static class PagingList<E> implements List<E> {
        private final List<E> parent;

        protected int allPageCount;

    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):
    return {"item_name": item.name, "item_id": item_id}
```

De `fastapi dev` server zou automatisch moeten herladen.

### Interactieve API documentatie upgrade

                        <ol class="breadcrumb float-sm-right">
                            <li class="breadcrumb-item"><la:link href="/admin/dict">
                                <la:message key="labels.dict_list_link"/>
                            </la:link></li>
                            <li class="breadcrumb-item"><la:link href="../list/1/?dictId=${f:u(dictId)}">
                                <la:message key="labels.dict_mapping_list_link"/>

                        <ol class="breadcrumb float-sm-right">
                            <li class="breadcrumb-item"><la:link href="/admin/dict">
                                <la:message key="labels.dict_list_link"/>
                            </la:link></li>
                            <li class="breadcrumb-item"><la:link href="../list/1/?dictId=${f:u(dictId)}">
                                <la:message key="labels.dict_synonym_list_link"/>

    items = {"foo": "The Foo Wrestlers"}


    @app.get("/items/{item_id}")
    async def read_item(item_id: str):
        if item_id not in items:
            raise HTTPException(status_code=404, detail="Item not found")
        return {"item": items[item_id]}
    ```
    """

    def __init__(
        self,
        status_code: Annotated[
            int,
            Doc(
                """

                "post": {
                    "summary": "Create Item",
                    "operationId": "create_item_items__post",
                    "requestBody": {
                        "content": {
                            "application/x-yaml": {
                                "schema": {
                                    "title": "Item",
                                    "required": ["name", "tags"],

#d6d8db;\n}\n\n.list-group-item-secondary.list-group-item-action:hover, .list-group-item-secondary.list-group-item-action:focus {\n  color: #383d41;\n  background-color: #c8cbcf;\n}\n\n.list-group-item-secondary.list-group-item-action.active {\n  color: #fff;\n  background-color: #383d41;\n  border-color: #383d41;\n}\n\n.list-group-item-success {\n  color: #155724;\n  background-color: #c3e6cb;\n}\n\n.list-group-item-success.list-group-item-action:hover, .list-group-item-success.list-group-item-action:focus {\n...