```
Client #1596980209979 left the chat
```

/// tip

The app above is a minimal and simple example to demonstrate how to handle and broadcast messages to several WebSocket connections.

But keep in mind that, as everything is handled in memory, in a single list, it will only work while the process is running, and will only work with a single process.

# Advanced Security { #advanced-security }

## Additional Features { #additional-features }

There are some extra features to handle security apart from the ones covered in the [Tutorial - User Guide: Security](../../tutorial/security/index.md){.internal-link target=_blank}.

/// tip

The next sections are **not necessarily "advanced"**.

And it's possible that for your use case, the solution is in one of them.

///

import java.util.concurrent.Executor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.jspecify.annotations.Nullable;

/**
 * Base class for implementing services that can handle {@link #doStart} and {@link #doStop}
 * requests, responding to them with {@link #notifyStarted()} and {@link #notifyStopped()}
 * callbacks. Its subclasses must manage threads manually; consider {@link

    class LifecycleAndExceptions {

        @Test
        @DisplayName("open() acquires handle and closes it")
        void openDelegatesEnsureOpenAndCloses() throws Exception {
            SmbFileInputStream in = newStream();
            in.open();
            // ensureOpen returns acquired handle; try-with-resources must close it
            verify(mockHandle, times(1)).close();

        assertEquals(4, bytesWritten);
        assertEquals(4, SMBUtil.readInt2(buffer, offset));
        assertEquals(0, SMBUtil.readInt2(buffer, offset + 2));
    }

    @Test
    @DisplayName("Should handle boundary conditions for buffer write")
    void testWriteBytesWireFormatBoundary() {
        // Given
        Configuration mockConfig = mock(Configuration.class);

            assertEquals(0, count, "No iterations should occur for empty iterator");
        }, "EmptyIterator should work with manual iteration");
    }

    @Test
    @DisplayName("EmptyIterator should handle concurrent access safely")
    void testConcurrentAccess() throws InterruptedException, CIFSException {
        // Given
        final int threadCount = 10;
        final Thread[] threads = new Thread[threadCount];

        // Override connectHost to avoid actual network connection on retry
        doAnswer(invocation -> {
            SmbTreeHandleImpl handle = mock(SmbTreeHandleImpl.class);
            // Re-set the same tree to continue using our mock
            setTree(c, tree);
            return handle;
        }).when(c).connectHost(any(), anyString());

        // Execute send - should retry after transport error
        try {

/// note

If you check the new (fake) database `fake_users_db`, you will see how the hashed password looks like now: `"$2b$12$EixZaYVK1fsbw1ZfbX3OXePaWxn96p36WQoeG6Lruj3vjPGga31lW"`.

///

## Handle JWT tokens { #handle-jwt-tokens }

Import the modules installed.

Create a random secret key that will be used to sign the JWT tokens.

To generate a secure random secret key use the command:

<div class="termy">

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

- ✅ Tests with [Pytest](https://pytest.org).
- 📞 [Traefik](https://traefik.io) as a reverse proxy / load balancer.
- 🚢 Deployment instructions using Docker Compose, including how to set up a frontend Traefik proxy to handle automatic HTTPS certificates.