feat: added notification pattern (#2629)

Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>

notification/src/main/java/com/iluwatar/RegisterWorkerForm.java

@@ -0,0 +1,66 @@
+package com.iluwatar;
+
+import java.time.LocalDate;
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * The form submitted by the user, part of the presentation layer,
+ * linked to the domain layer through a data transfer object and
+ * linked to the service layer directly.
+ */
+@Slf4j
+public class RegisterWorkerForm {
+  String name;
+  String occupation;
+  LocalDate dateOfBirth;
+  RegisterWorkerDto worker;
+  RegisterWorkerService service = new RegisterWorkerService();
+
+  /**
+   *  Constructor.
+   *
+   * @param name        Name of the worker
+   * @param occupation  occupation of the worker
+   * @param dateOfBirth Date of Birth of the worker
+   */
+  public RegisterWorkerForm(String name, String occupation, LocalDate dateOfBirth) {
+    this.name = name;
+    this.occupation = occupation;
+    this.dateOfBirth = dateOfBirth;
+  }
+
+  /**
+   * Attempts to submit the form for registering a worker.
+   */
+  public void submit() {
+    //Transmit information to our transfer object to communicate between layers
+    saveToWorker();
+    //call the service layer to register our worker
+    service.registerWorker(worker);
+
+    //check for any errors
+    if (worker.getNotification().hasErrors()) {
+      indicateErrors();
+      LOGGER.info("Not registered, see errors");
+    } else {
+      LOGGER.info("Registration Succeeded");
+    }
+  }
+
+  /**
+   * Saves worker information to the data transfer object.
+   */
+  private void saveToWorker() {
+    worker = new RegisterWorkerDto();
+    worker.setName(name);
+    worker.setOccupation(occupation);
+    worker.setDateOfBirth(dateOfBirth);
+  }
+
+  /**
+   * Check for any errors with form submission and show them to the user.
+   */
+  public void indicateErrors() {
+    worker.getNotification().getErrors().forEach(error -> LOGGER.error(error.toString()));
+  }
+}