/// note | Nota

Si usas una clase de response sin media type, FastAPI esperará que tu response no tenga contenido, por lo que no documentará el formato del response en su OpenAPI generado.

///

## Responses JSON { #json-responses }

Por defecto FastAPI devuelve responses JSON.

     */
    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()

        // nothing

        return appendQueryParameter(document, url);
    }

    /**
     * Updates file protocol based on user agent type.
     * Handles different browser-specific file protocol formats.
     *
     * @param url the file URL to update
     * @return the updated URL with appropriate file protocol
     */
    protected String updateFileProtocol(String url) {

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);