Esto es útil para operaciones que necesitan ocurrir después de un request, pero para las que el cliente realmente no necesita esperar a que la operación termine antes de recibir el response.

Esto incluye, por ejemplo:

* Notificaciones por email enviadas después de realizar una acción:

 *
 * <p>It is generally safe for <i>applications</i> to depend on beta APIs, at the cost of some extra
 * work during upgrades. However it is generally inadvisable for <i>libraries</i> (which get
 * included on users' CLASSPATHs, outside the library developers' control) to do so.
 *
 * @author Kevin Bourrillion
 */
@Retention(RetentionPolicy.CLASS)
@Target({
  ElementType.ANNOTATION_TYPE,
  ElementType.CONSTRUCTOR,

 *
 * <p>It is generally safe for <i>applications</i> to depend on beta APIs, at the cost of some extra
 * work during upgrades. However it is generally inadvisable for <i>libraries</i> (which get
 * included on users' CLASSPATHs, outside the library developers' control) to do so.
 *
 * @author Kevin Bourrillion
 */
@Retention(RetentionPolicy.CLASS)
@Target({
  ElementType.ANNOTATION_TYPE,
  ElementType.CONSTRUCTOR,

        ldap: ["", "localhost:389"]
        etcd: ["", "http://localhost:2379"]
        openid: ["", "http://127.0.0.1:5556/dex"]
        exclude:
          # exclude combos where all are empty.
          - ldap: ""
            etcd: ""
            openid: ""
          # exclude combos where both ldap and openid IDPs are specified.
          - ldap: "localhost:389"
            openid: "http://127.0.0.1:5556/dex"

    steps:

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Immutable;

/**
 * An {@link Artifact} that is being produced by a {@link Project} during the build.
 *
 * <p>Produced artifacts includes:</p><ul>
 *     <li>{@linkplain Project#getPomArtifact() the project POM artifact}</li>
 *     <li>{@linkplain Project#getMainArtifact() the main artifact}</li>

copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

        assertEquals(e.getMessage(), NbtException.getErrorString(NbtException.ERR_SSN_SRVC, NbtException.CONNECTION_REFUSED));
    }

    @Test
    @DisplayName("toString includes class, code and error string")
    void testToString() {
        NbtException e = new NbtException(NbtException.ERR_SSN_SRVC, NbtException.NO_RESOURCES);
        String str = e.toString();

Puedes usar esta plantilla para comenzar, ya que incluye gran parte de la configuración inicial, seguridad, base de datos y algunos endpoints de API ya hechos para ti.

You can use this template to get started, as it includes a lot of the initial set up, security, database and some API endpoints already done for you.