* <li>the exception itself,</li>
 * <li>useful end-user message,</li>
 * <li>useful reference to a solution, or set of solutions: this is usually a wiki page url in
 * <a href="http://cwiki.apache.org/confluence/display/MAVEN/">http://cwiki.apache.org/confluence/display/MAVEN/</a>,
 * </li>
 * <li>child exception summaries.</li>
 * </ul>
 */
public class ExceptionSummary {

    private Throwable exception;

<address xmlns:hoge="http://www.example.com/hoge">
        <item sex="male" custid="A12345">
                <name>鈴木太郎</name>
                <access kind="email"></access>
                <access kind="url">http://www.taro.com/</access>
                <image file="taro.png" />
        </item>
        <item sex="male" custid="B23456">
                <name>佐藤二朗</name>
                <access kind="email">******@****.***</access>

 * Copyright (C) 2020 Square, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

   <span style="background-color:#007166"><font color="#D3D7CF"> server </font></span>  Documentation at <font color="#729FCF"><u style="text-decoration-style:solid">http://127.0.0.1:8000/docs</u></font>

   <span style="background-color:#007166"><font color="#D3D7CF"> server </font></span>  Documentation at <font color="#729FCF"><u style="text-decoration-style:solid">http://127.0.0.1:8000/docs</u></font>

 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

# 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`。

app = FastAPI(
    title="ChimichangApp",
    description=description,
    summary="Deadpool's favorite app. Nuff said.",
    version="0.0.1",
    terms_of_service="http://example.com/terms/",
    contact={
        "name": "Deadpoolio the Amazing",
        "url": "http://x-force.example.com/contact/",
        "email": "******@****.***",
    },
    license_info={
        "name": "Apache 2.0",
        "identifier": "MIT",