*/
    return ref == null ? Optional.absent() : Optional.fromNullable(enumClass.cast(ref.get()));
  }

  static String formatCompact4Digits(double value) {
    return String.format(Locale.ROOT, "%.4g", value);
  }

  static boolean stringIsNullOrEmpty(@Nullable String string) {
    return string == null || string.isEmpty();
  }

  /**

    /**
     * Proxy server port
     */
    private int port;

    /**
     * Type of the proxy
     */
    private String protocol;

    /**
     * The non-proxy hosts. Follows Java system property format: <code>*.foo.com|localhost</code>.
     */
    private String nonProxyHosts;

    /**
     * For NTLM proxies, specifies the NTLM host.
     */
    private String ntlmHost;

    /**

# Server-Sent Events (SSE) { #server-sent-events-sse }

Sie können Daten mithilfe von **Server-Sent Events** (SSE) an den Client streamen.

Das ist ähnlich wie [JSON Lines streamen](stream-json-lines.md), verwendet aber das Format `text/event-stream`, das von Browsern nativ mit der [die `EventSource`-API](https://developer.mozilla.org/en-US/docs/Web/API/EventSource) unterstützt wird.

/// info | Info

Hinzugefügt in FastAPI 0.135.0.

///

6. Ici, nous renvoyons un dictionnaire qui contient `items`, qui est une liste de dataclasses.

    FastAPI est toujours capable de <dfn title="convertir les données dans un format pouvant être transmis">sérialiser</dfn> les données en JSON.

7. Ici, `response_model` utilise une annotation de type correspondant à une liste de dataclasses `Author`.

                return Files.walk(yamlTestOutputDir.toPath()).anyMatch(p -> p.getFileName().toString().endsWith("yml"));
            }
        } catch (IOException e) {
            throw new IllegalStateException(String.format("Error determining if this project [%s] has rest tests.", getProject()), e);
        }
        return false;
    }

    public void setSourceResourceDir(File sourceResourceDir) {

java.net.InetSocketAddress#<init>(int)
java.net.MulticastSocket#<init>()
java.net.MulticastSocket#<init>(int)
java.net.ServerSocket#<init>(int)
java.net.ServerSocket#<init>(int,int)

@defaultMessage use NetworkAddress format() to print IP or IP+ports
java.net.InetAddress#toString()
java.net.InetAddress#getHostAddress()
java.net.Inet4Address#getHostAddress()
java.net.Inet6Address#getHostAddress()
java.net.InetSocketAddress#toString()

        return asJson(new ApiBackupFilesResponse().files(list).total(list.size()).status(ApiResult.Status.OK).result());
    }

    /**
     * Downloads a specific backup file by ID.
     * Supports various backup formats including system properties, bulk data, and NDJSON logs.
     *
     * @param id the backup file ID to download
     * @return stream response containing the backup file data
     */
    // GET /api/admin/backup/file/{id}

También te da mucha responsabilidad. Tienes que asegurarte de que los datos que devuelves sean correctos, en el formato correcto, que se puedan serializar, etc.

## Usar el `jsonable_encoder` en una `Response` { #using-the-jsonable-encoder-in-a-response }

Tokenizer tokenizer = new Tokenizer("field1,field2,field3", ",");
while (tokenizer.hasMoreTokens()) {
    String token = tokenizer.nextToken();
    // Process each token
}

// Decimal formatting
DecimalFormat format = DecimalFormatUtil.getDecimalFormat("###,###.00");
```

### Exception Handling
```java
import org.codelibs.core.exception.*;

// Runtime exception wrappers eliminate try-catch boilerplate
try {

                    this.fp += cnt;
                    len -= cnt;
                    off += cnt;
                } else {
                    if (log.isTraceEnabled()) {
                        log.trace(String.format("Wrote at %d remain %d off %d len %d", this.fp, len - w, off, w));
                    }
                    this.req.setParam(fh.getFid(), this.fp, len - w, b, off, w);
                    th.send(this.req, this.rsp);