{* ../../docs_src/security/tutorial005.py hl[105,107:115] *}

## 校验 `username` 与数据形状

我们可以校验是否获取了 `username`，并抽取作用域。

然后，使用 Pydantic 模型校验数据（捕获 `ValidationError` 异常），如果读取 JWT 令牌或使用 Pydantic 模型验证数据时出错，就会触发之前创建的 `HTTPException` 异常。

对此，要使用新的属性 `scopes` 更新 Pydantic 模型 `TokenData`。

使用 Pydantic 验证数据可以确保数据中含有由作用域组成的**字符串列表**，以及 `username` 字符串等内容。

反之，如果使用**字典**或其它数据结构，就有可能在后面某些位置破坏应用，形成安全隐患。

        final String username = systemHelper.getUsername();
        runtime.registerData("username", username);
        runtime.registerData("editableUser", fessLoginAssist.getSavedUserBean().map(FessUserBean::isEditable).orElse(false));
        runtime.registerData("adminUser",
                fessConfig.isAdminUser(username) || fessLoginAssist.getSavedUserBean()

	oeConfig DiscoveryDoc
	client   http.Client
	adminURL string
	realm    string

	// internal value refreshed
	accessToken Token
}

// LoginWithUser authenticates username/password, not needed for Keycloak
func (k *KeycloakProvider) LoginWithUser(username, password string) error {
	return ErrNotImplemented
}

// LoginWithClientID is implemented by Keycloak service account support

    default String getLdapSecurityPrincipal(final String username) {
        final String value;
        final int maxLength = getLdapMaxUsernameLengthAsInteger();
        if (username == null) {
            value = StringUtil.EMPTY;
        } else if (maxLength >= 0 && username.length() > maxLength) {
            value = username.substring(0, maxLength);
        } else {
            value = username;
        }

        get() = System.getProperty("slow.internet.connection", "false")!!.toBoolean()
    val agentNum: Int
        get() {
            if (System.getenv().containsKey("USERNAME")) {
                val agentNumEnv = System.getenv("USERNAME").replaceFirst("tcagent", "")
                if (Regex("""\d+""").containsMatchIn(agentNumEnv)) {
                    return agentNumEnv.toInt()
                }
            }

        //    <proxy>
        //      <active>true</active>
        //      <protocol>http</protocol>
        //      <host>proxy.somewhere.com</host>
        //      <port>8080</port>
        //      <username>proxyuser</username>
        //      <password>somepassword</password>
        //      <nonProxyHosts>www.google.com|*.somewhere.com</nonProxyHosts>
        //    </proxy>
        //  </proxies>

client = TestClient(app)


@pytest.mark.parametrize(
    "path,expected_status,expected_response",
    [
        ("/items/", 200, [{"name": "Foo", "price": 42}]),
        ("/users/", 200, [{"username": "johndoe"}]),
        ("/elements/", 200, [{"item_id": "Foo"}]),
    ],
)
def test_query_params_str_validations(path, expected_status, expected_response):
    response = client.get(path)

            "type" : "keyword"
          },
          "updatedBy" : {
            "type" : "keyword"
          },
          "updatedTime" : {
            "type" : "long"
          },
          "username" : {
            "type" : "keyword"
          },
          "webConfigId" : {
            "type" : "keyword"
          }
        }
      }
    },
    "settings" : {
      "index" : {

							<c:choose>
								<c:when test="${!empty username && username != 'guest'}">
									<li class="nav-item">
										<div class="dropdown">
											<a id="userMenu" class="nav-link dropdown-toggle" data-bs-toggle="dropdown"
												href="#" role="button" aria-haspopup="true" aria-expanded="false"
											> <i class="fa fa-fw fa-user" aria-hidden="true"></i>${username}
											</a>

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()):