## Default response class { #default-response-class }

When creating a **FastAPI** class instance or an `APIRouter` you can specify which response class to use by default.

The parameter that defines this is `default_response_class`.

In the example below, **FastAPI** will use `HTMLResponse` by default, in all *path operations*, instead of JSON.

import jakarta.validation.constraints.Size;

/**
 * The mail form for General settings.
 */
public class MailForm {

    /**
     * Default constructor.
     */
    public MailForm() {
        // Default constructor
    }

    /** The incremental crawling setting. */
    public String incrementalCrawling;

    /** The day for cleanup setting. */
    public String dayForCleanup;

 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingSetMultimap}.
 *
 * @author Kurt Alfred Kluever

     * @return the phase
     */
    @Nonnull
    String phase() default "";

    /**
     * Goal to fork. Note that specifying a phase overrides specifying a goal. The specified <code>goal</code> must be
     * another goal of the same plugin.
     * @return the goal
     */
    @Nonnull
    String goal() default "";

    /**

    Artifact create(@Nonnull ArtifactFactoryRequest request);

    @Nonnull
    default Artifact create(
            @Nonnull Session session, String groupId, String artifactId, String version, String extension) {
        return create(ArtifactFactoryRequest.build(session, groupId, artifactId, version, extension));
    }

    @Nonnull
    default Artifact create(
            @Nonnull Session session,
            String groupId,

					if err != nil {
						err = msgp.WrapError(err, "Purge", "RetainVersions")
						return
					}
				default:
					err = dc.Skip()
					if err != nil {
						err = msgp.WrapError(err, "Purge")
						return
					}
				}
			}
		default:
			err = dc.Skip()
			if err != nil {
				err = msgp.WrapError(err)
				return
			}
		}
	}
	return
}

        fessConfig.setSystemProperty("oic.scope", form.oicScope);
        fessConfig.setSystemProperty("oic.base.url", form.oicBaseUrl);
        fessConfig.setSystemProperty("oic.default.groups", form.oicDefaultGroups);
        fessConfig.setSystemProperty("oic.default.roles", form.oicDefaultRoles);

        // SAML
        fessConfig.setSystemProperty("saml.sp.base.url", form.samlSpBaseUrl);

    /**
     * Default constructor for PurgeThumbnailJob.
     * Creates a new instance of the thumbnail purging job with default expiry time (30 days).
     */
    public PurgeThumbnailJob() {
        // Default constructor
    }

    /** Expiration time for thumbnails in milliseconds (default: 30 days) */
    private long expiry = 30 * 24 * 60 * 60 * 1000L;

    /**

 *
 * <p><b>{@code default} method warning:</b> This class forwards calls to <i>only some</i> {@code
 * default} methods. Specifically, it forwards calls only for methods that existed <a
 * href="https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ConcurrentMap.html">before
 * {@code default} methods were introduced</a>. For newer methods, like {@code forEach}, it inherits

///

## Die Default-Exceptionhandler überschreiben { #override-the-default-exception-handlers }

**FastAPI** hat einige Default-Exceptionhandler.

Diese Handler sind dafür verantwortlich, die Default-JSON-Responses zurückzugeben, wenn Sie eine `HTTPException` `raise`n und wenn der Request ungültige Daten enthält.