Y quieres manejar esta excepción globalmente con FastAPI.

Podrías agregar un manejador de excepciones personalizado con `@app.exception_handler()`:

{* ../../docs_src/handling_errors/tutorial003_py39.py hl[5:7,13:18,24] *}

Aquí, si solicitas `/unicorns/yolo`, la *path operation* lanzará un `UnicornException`.

from starlette.exceptions import HTTPException as StarletteHTTPException

app = FastAPI()


@app.exception_handler(StarletteHTTPException)
async def http_exception_handler(request, exc):
    return PlainTextResponse(str(exc.detail), status_code=exc.status_code)


@app.exception_handler(RequestValidationError)
async def validation_exception_handler(request, exc: RequestValidationError):
    message = "Validation errors:"

    @Inject
    private LifeCyclePluginAnalyzer lifeCyclePluginAnalyzer;

    @Inject
    private LifecycleTaskSegmentCalculator lifeCycleTaskSegmentCalculator;

    @Inject
    private ExceptionHandler exceptionHandler;

    protected String getProjectsDirectory() {
        return "src/test/projects/lifecycle-executor";
    }

    @Test
    void testCreation() throws Exception {

from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse


class UnicornException(Exception):
    def __init__(self, name: str):
        self.name = name


app = FastAPI()


@app.exception_handler(UnicornException)
async def unicorn_exception_handler(request: Request, exc: UnicornException):
    return JSONResponse(
        status_code=418,

from fastapi.encoders import jsonable_encoder
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse
from pydantic import BaseModel

app = FastAPI()


@app.exception_handler(RequestValidationError)
async def validation_exception_handler(request: Request, exc: RequestValidationError):
    return JSONResponse(
        status_code=422,

        MojoExecutionException mojoEx =
                new MojoExecutionException("Error executing Jetty: Unable to establish loopback connection", ioEx);

        ExceptionHandler exceptionHandler = new DefaultExceptionHandler();
        ExceptionSummary exceptionSummary = exceptionHandler.handleException(mojoEx);

        String expectedReference = "http://cwiki.apache.org/confluence/display/MAVEN/ConnectException";

            - put
            - post
            - delete
            - options
            - head
            - patch
            - trace
            - on_event
            - middleware

def server_error_exception_handler(request, exception):
    return JSONResponse(status_code=500, content={"exception": "server-error"})


app = FastAPI(
    exception_handlers={
        HTTPException: http_exception_handler,
        RequestValidationError: request_validation_exception_handler,
        Exception: server_error_exception_handler,
    }
)

client = TestClient(app)

 evaluate plugin parameters values during Mojo configuration,

 * <<<ExceptionHandler>>> component ({{{./apidocs/org/apache/maven/exception/ExceptionHandler.html}javadoc}}),
 with its <<<DefaultExceptionHandler>>> implementation

あなた（または使用しているライブラリ）が`raise`するかもしれないカスタム例外`UnicornException`があるとしましょう。

そして、この例外をFastAPIでグローバルに処理したいと思います。

カスタム例外ハンドラを`@app.exception_handler()`で追加することができます:

{* ../../docs_src/handling_errors/tutorial003.py hl[5,6,7,13,14,15,16,17,18,24] *}

ここで、`/unicorns/yolo`をリクエストすると、*path operation*は`UnicornException`を`raise`します。