self.skip = skip
        self.limit = limit


@app.get("/items/")
async def read_items(commons: Annotated[CommonQueryParams, Depends(CommonQueryParams)]):
    response = {}
    if commons.q:
        response.update({"q": commons.q})
    items = fake_items_db[commons.skip : commons.skip + commons.limit]
    response.update({"items": items})

app = FastAPI()


async def common_parameters(q: str | None = None, skip: int = 0, limit: int = 100):
    return {"q": q, "skip": skip, "limit": limit}


CommonsDep = Annotated[dict, Depends(common_parameters)]


@app.get("/items/")
async def read_items(commons: CommonsDep):
    return commons


@app.get("/users/")
async def read_users(commons: CommonsDep):

 */
package org.apache.maven.project.harness;

import java.io.File;
import java.util.Iterator;
import java.util.Objects;

import org.apache.commons.jxpath.JXPathContext;
import org.apache.commons.jxpath.JXPathNotFoundException;
import org.apache.commons.jxpath.ri.JXPathContextReferenceImpl;
import org.apache.maven.project.MavenProject;

public class PomTestWrapper {

    private File pomFile;

    ```Python
    commons: Annotated[CommonQueryParams, Depends(CommonQueryParams)]
    ```

=== "Python 3.8+ non-Annotated"

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python
    commons: CommonQueryParams = Depends(CommonQueryParams)
    ```

...you write:

=== "Python 3.8+"

    ```Python
    commons: Annotated[CommonQueryParams, Depends()]

app = FastAPI()


async def common_parameters(
    q: Union[str, None] = None, skip: int = 0, limit: int = 100
):
    return {"q": q, "skip": skip, "limit": limit}


@app.get("/items/")
async def read_items(commons: Annotated[dict, Depends(common_parameters)]):
    return {"message": "Hello Items!", "params": commons}


@app.get("/users/")
async def read_users(commons: Annotated[dict, Depends(common_parameters)]):

        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")
async def read_items(commons: Annotated[Any, Depends(CommonQueryParams)]):
    response = {}
    if commons.q:
        response.update({"q": commons.q})
    items = fake_items_db[commons.skip : commons.skip + commons.limit]
    response.update({"items": items})

        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")
async def read_items(commons: CommonQueryParams = Depends(CommonQueryParams)):
    response = {}
    if commons.q:
        response.update({"q": commons.q})
    items = fake_items_db[commons.skip : commons.skip + commons.limit]
    response.update({"items": items})

        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")
async def read_items(commons: Annotated[Any, Depends(CommonQueryParams)]):
    response = {}
    if commons.q:
        response.update({"q": commons.q})
    items = fake_items_db[commons.skip : commons.skip + commons.limit]
    response.update({"items": items})

    ```Python hl_lines="19"
    {!> ../../../docs_src/dependencies/tutorial002.py!}
    ```

**FastAPI** 调用 `CommonQueryParams` 类。这将创建该类的一个 "实例"，该实例将作为参数 `commons` 被传递给你的函数。

## 类型注解 vs `Depends`

注意，我们在上面的代码中编写了两次`CommonQueryParams`：

```Python
commons: CommonQueryParams = Depends(CommonQueryParams)
```

最后的 `CommonQueryParams`:

```Python
... = Depends(CommonQueryParams)
```

    val commonsCodec = "commons-codec:commons-codec"
    val commonsCompress = "org.apache.commons:commons-compress"
    val commonsHttpclient = "org.apache.httpcomponents:httpclient"
    val commonsIo = "commons-io:commons-io"
    val commonsLang = "commons-lang:commons-lang"
    val commonsLang3 = "org.apache.commons:commons-lang3"
    val commonsMath = "org.apache.commons:commons-math3"