# Exceptions - `HTTPException` and `WebSocketException`

These are the exceptions that you can raise to show errors to the client.

When you raise an exception, as would happen with normal Python, the rest of the execution is aborted. This way you can raise these exceptions from anywhere in the code to abort a request and show the error to the client.

You can use:

* `HTTPException`
* `WebSocketException`

from pydantic import BaseModel, create_model
from starlette.exceptions import HTTPException as StarletteHTTPException
from starlette.exceptions import WebSocketException as StarletteWebSocketException


class EndpointContext(TypedDict, total=False):
    function: str
    path: str
    file: str
    line: int


class HTTPException(StarletteHTTPException):
    """
    An HTTP exception you can raise in your own code to show errors to the client.

    // Exceptions
    // ------------------------------------------------------------------------

    public boolean hasExceptions() {
        return exceptions != null && !exceptions.isEmpty();
    }

    public List<Exception> getExceptions() {
        return exceptions == null ? Collections.emptyList() : Collections.unmodifiableList(exceptions);
    }

    // Exceptions
    // ------------------------------------------------------------------------

    public boolean hasExceptions() {
        return exceptions != null && !exceptions.isEmpty();
    }

    public List<Exception> getExceptions() {
        return exceptions == null ? Collections.emptyList() : Collections.unmodifiableList(exceptions);
    }

    }

    @Override
    public void close() throws Exception {
        ArrayList<Exception> exceptions = new ArrayList<>();
        for (CommandRegistry commandRegistry : commandRegistries) {
            if (commandRegistry instanceof AutoCloseable closeable) {
                try {
                    closeable.close();
                } catch (Exception e) {
                    exceptions.add(e);
                }
            }
        }

                } catch (e: Exception) {
                    exceptions.add(e)
                }
            }
        when {
            exceptions.size == 1 -> throw exceptions.first()
            exceptions.isNotEmpty() -> throw DefaultMultiCauseException("Test files cleanup verification failed", exceptions)
            else -> {
            }
        }
    }

        ArrayList<Exception> exceptions = new ArrayList<>();
        for (MavenContext context : residentContext.values()) {
            try {
                context.doCloseContainer();
            } catch (Exception e) {
                exceptions.add(e);
            }
        }
        if (!exceptions.isEmpty()) {

from fastapi import FastAPI, HTTPException
from fastapi.exceptions import RequestValidationError
from fastapi.responses import PlainTextResponse
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)

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[8,13] *}

### Exceptions auslösen { #raise-exceptions }

Die Abhängigkeiten können Exceptions `raise`n, genau wie normale Abhängigkeiten:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[10,15] *}

### Rückgabewerte { #return-values }

{* ../../docs_src/handling_errors/tutorial002_py39.py hl[14] *}

## Install custom exception handlers { #install-custom-exception-handlers }

You can add custom exception handlers with <a href="https://www.starlette.dev/exceptions/" class="external-link" target="_blank">the same exception utilities from Starlette</a>.

Let's say you have a custom exception `UnicornException` that you (or a library you use) might `raise`.