TestCorsHandler handler1 = new TestCorsHandler("handler1");
        TestCorsHandler handler2 = new TestCorsHandler("handler2");
        TestCorsHandler handler3 = new TestCorsHandler("handler3");

        // Execute
        corsHandlerFactory.add(origin1, handler1);
        corsHandlerFactory.add(origin2, handler2);
        corsHandlerFactory.add(origin3, handler3);

        // Verify

    when (type) {
      TYPE_DATA -> readData(handler, length, flags, streamId)
      TYPE_HEADERS -> readHeaders(handler, length, flags, streamId)
      TYPE_PRIORITY -> readPriority(handler, length, flags, streamId)
      TYPE_RST_STREAM -> readRstStream(handler, length, flags, streamId)
      TYPE_SETTINGS -> readSettings(handler, length, flags, streamId)
      TYPE_PUSH_PROMISE -> readPushPromise(handler, length, flags, streamId)

        private String lastOrigin = null;
        private CorsHandler handler = null;

        @Override
        public CorsHandler get(String origin) {
            getCalled = true;
            lastOrigin = origin;
            return handler;
        }

        public void setHandler(CorsHandler handler) {
            this.handler = handler;
        }

        public boolean wasGetCalled() {

///

## Override the default exception handlers { #override-the-default-exception-handlers }

**FastAPI** has some default exception handlers.

These handlers are in charge of returning the default JSON responses when you `raise` an `HTTPException` and when the request has invalid data.

You can override these exception handlers with your own.

  private TestLogHandler handler;
  private final TearDownStack stack = new TearDownStack();

  @Override
  protected void setUp() throws Exception {
    super.setUp();

    handler = new TestLogHandler();

    // You could also apply it higher up the Logger hierarchy than this
    ExampleClassUnderTest.logger.addHandler(handler);

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield
participant operation as Path Operation
participant tasks as Background tasks

    Note over client,operation: Can raise exceptions, including HTTPException
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise Exception
        dep -->> handler: Raise Exception

  private TestLogHandler handler;
  private final TearDownStack stack = new TearDownStack();

  @Override
  protected void setUp() throws Exception {
    super.setUp();

    handler = new TestLogHandler();

    // You could also apply it higher up the Logger hierarchy than this
    ExampleClassUnderTest.logger.addHandler(handler);

In this case, the `startup` event handler function will initialize the items "database" (just a `dict`) with some values.

You can add more than one event handler function.

And your application won't start receiving requests until all the `startup` event handlers have completed.

### `shutdown` event { #shutdown-event }

## Accessing the request body in an exception handler { #accessing-the-request-body-in-an-exception-handler }

/// tip

To solve this same problem, it's probably a lot easier to use the `body` in a custom handler for `RequestValidationError` ([Handling Errors](../tutorial/handling-errors.md#use-the-requestvalidationerror-body)).

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield
participant operation as Path Operation
participant tasks as Background tasks

    Note over client,operation: Can raise exceptions, including HTTPException
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise Exception
        dep -->> handler: Raise Exception