#7 Perfil de Personal Administrativo - Listado de empleados (Navegacion de paginas)

src/main/java/com/primefactorsolutions/service/EmployeeService.java

@@ -1,10 +1,11 @@
 package com.primefactorsolutions.service;
 
-import com.primefactorsolutions.model.Candidate;
 import com.primefactorsolutions.model.Employee;
 import com.primefactorsolutions.repositories.EmployeeRepository;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
 import lombok.Data;
-import org.apache.commons.lang3.NotImplementedException;
 import org.springframework.stereotype.Service;
 
 import java.util.List;
@@ -31,4 +32,14 @@ public class EmployeeService {
     public Employee getEmployee(final UUID id) {
         return null;
     }
+
+    public Page<Employee> getEmployeesPaginated(int pageNo, int pageSize) {
+        Pageable pageable = PageRequest.of(pageNo - 1, pageSize);
+        return employeeRepository.findAll(pageable);
+    }
+
+    public boolean hasNextPage(int currentPage, int pageSize) {
+        Page<Employee> page = getEmployeesPaginated(currentPage, pageSize);
+        return page.hasNext();
+    }
 }

src/main/java/com/primefactorsolutions/views/EmployeesListView.java

@@ -10,19 +10,14 @@ import com.vaadin.flow.component.combobox.ComboBox;
 import com.vaadin.flow.component.html.H2;
 import com.vaadin.flow.component.html.Main;
 import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
-import com.vaadin.flow.data.provider.DataProvider;
-import com.vaadin.flow.data.provider.DataProviderListener;
-import com.vaadin.flow.data.provider.Query;
 import com.vaadin.flow.function.ValueProvider;
 import com.vaadin.flow.router.PageTitle;
 import com.vaadin.flow.router.Route;
-import com.vaadin.flow.shared.Registration;
 import com.vaadin.flow.spring.annotation.SpringComponent;
 import jakarta.annotation.security.PermitAll;
 import org.springframework.context.annotation.Scope;
 import org.vaadin.firitin.components.grid.VGrid;
-
+import org.springframework.data.domain.Page;
-import java.util.stream.Stream;
 
 @SpringComponent
 @Scope("prototype")
@@ -31,6 +26,10 @@ import java.util.stream.Stream;
 @PermitAll
 public class EmployeesListView extends Main {
     private final EmployeeService employeeService;
+    private int currentPage = 1;
+    private final int pageSize = 5;
+    private final Button previous;
+    private final Button next;
 
     public EmployeesListView(final EmployeeService employeeService) {
         this.employeeService = employeeService;
@@ -69,58 +68,34 @@ public class EmployeesListView extends Main {
             });
             return save;
         });
-
+        this.previous = new Button("Previous");
-        grid.setDataProvider(new DataProvider<>() {
+        this.previous.addClickListener((ComponentEventListener<ClickEvent<Button>>) buttonClickEvent -> {
-            @Override
+            if (currentPage > 1) {
-            public boolean isInMemory() {
+                currentPage--;
-                return false;
+                updateGrid(grid);
-            }
-
-            @Override
-            public int size(final Query<Employee, Object> query) {
-                return employeeService.getEmployees().size();
-            }
-
-            @Override
-            public Stream<Employee> fetch(final Query<Employee, Object> query) {
-                int limit = query.getLimit();
-                int pagerSize = query.getPageSize();
-                int page = query.getPage();
-                return employeeService.getEmployees().stream();
-            }
-
-            @Override
-            public void refreshItem(final Employee employee) {
-                // no-op
-            }
-
-            @Override
-            public void refreshAll() {
-                // no-op
-            }
-
-            @Override
-            public Registration addDataProviderListener(final DataProviderListener<Employee> dataProviderListener) {
-                return null;
             }
         });
-
+        hf.add(this.previous);
-        final Button previous = new Button("Previous");
+        this.next = new Button("Next");
-        previous.addClickListener((ComponentEventListener<ClickEvent<Button>>) buttonClickEvent -> {
+        this.next.addClickListener((ComponentEventListener<ClickEvent<Button>>) buttonClickEvent -> {
-            // no-op
+            if (employeeService.hasNextPage(currentPage, pageSize)) {
+                currentPage++;
+                updateGrid(grid);
+            }
         });
-        hf.add(previous);
+        hf.add(this.next);
-        final Button next = new Button("Next");
-        next.addClickListener((ComponentEventListener<ClickEvent<Button>>) buttonClickEvent -> {
-            //  no-op
-        });
-        hf.add(next);
         final Button addEmployee = new Button("Add Employee");
         addEmployee.addClickListener((ComponentEventListener<ClickEvent<Button>>) buttonClickEvent -> {
-            this.getUI().get().navigate(EmployeeView.class, "new");
+            this.getUI().flatMap(ui -> ui.navigate(EmployeeView.class, "new"));
         });
         hf.add(addEmployee);
-
         add(title, hl, grid, hf);
+        updateGrid(grid);
+    }
+    private void updateGrid(VGrid<Employee> grid) {
+        Page<Employee> page = employeeService.getEmployeesPaginated(currentPage, pageSize);
+        grid.setItems(page.getContent());
+        this.previous.setEnabled(currentPage > 1);
+        this.next.setEnabled(page.hasNext());
     }
 }

src/main/resources/data.sql

@@ -13,4 +13,15 @@ insert into employee (id, version, first_name, last_name, status) values ('e99b7
 insert into employee (id, version, first_name, last_name, status) values ('f6ab3c6d-7078-45f6-9b22-4e37637bfec6', 1, 'Ana', 'Garcia Rojas', 'ACTIVE');
 insert into employee (id, version, first_name, last_name, status) values ('2e2293b1-3f9a-4f3d-abc8-32639b0a5e15', 1, 'Carlos', 'Lopez Mendoza', 'INACTIVE');
 insert into employee (id, version, first_name, last_name, status) values ('4b1c6c35-4627-4b35-b6e9-dc75c68b2c31', 1, 'Maria', 'Fernandez Villca', 'ACTIVE');
-insert into employee (id, version, first_name, last_name, status) values ('afc5c741-f70a-4394-853b-39d51b118927', 1, 'Luis', 'Gutierrez Mamani', 'ACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('afc5c741-f70a-4394-853b-39d51b118927', 1, 'Luis', 'Gutierrez Mamani', 'ACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('b2436b82-7b9f-4f0d-9463-f2c3173a45c3', 1, 'Laura', 'Martinez Paredes', 'INACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('6e6a8a4e-9f6b-44eb-8c69-40acfdc86756', 1, 'Roberto', 'Santos Escobar', 'ACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('36b0d1c6-bdc0-4d98-94bb-08b9bce3f0d5', 1, 'Valeria', 'Morales Ochoa', 'INACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('5a1c6d80-58b3-43e3-a5a5-24b4a2d1d54a', 1, 'Jorge', 'Ramirez Tapia', 'ACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('9d6a5b2e-6d0b-4b89-8d6a-d3f3d1bfc047', 1, 'Sandra', 'Torres Huanca', 'ACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('f8b3e0c0-0d5a-4e5c-bf9d-207b9b5e8279', 1, 'Felipe', 'Quispe Huanca', 'INACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('cd80e1d0-9a08-44a6-bd63-2c63eaa003d4', 1, 'Gabriela', 'Rivas Arana', 'ACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('62d3c1b7-815e-4e96-8d7e-f8c4236bca55', 1, 'Oscar', 'Flores Quiroga', 'INACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('f20b7c5a-5a67-44f0-9ec1-4c1b8e80de05', 1, 'Marta', 'Vargas Soria', 'ACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('19b5a76e-d7b1-4b76-8b02-4d0748e85809', 1, 'Andres', 'Espinoza Chura', 'INACTIVE');
+insert into employee (id, version, first_name, last_name, status) values ('5c1a7b82-832d-4f24-8377-54b77b91b6a8', 1, 'Carla', 'Villanueva Arce', 'ACTIVE');