iluwatar#348 - Data Tranfer Object : Implement Data Transfer Object pattern simple version.

Gopinath Langote · Gopinath Langote · commit 148de06bb1f0 · 2017-08-11T15:42:21.000+05:30
diff --git a/data-transfer-object/src/main/java/com/iluwatar/datatransfer/CustomerDto.java b/data-transfer-object/src/main/java/com/iluwatar/datatransfer/CustomerDto.java
@@ -0,0 +1,60 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Gopinath Langote
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * 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,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.iluwatar.datatransfer;
+
+/**
+ * {@link CustomerDto} is a data transfer object POJO. Instead of sending individual information to client
+ * We can send related information together in POJO.
+ * <p>
+ * Dto will not have any business logic in it.
+ */
+public class CustomerDto {
+  private String id;
+  private String firstName;
+  private String lastName;
+
+  /**
+   * @param id        customer id
+   * @param firstName customer first name
+   * @param lastName  customer last name
+   */
+  public CustomerDto(String id, String firstName, String lastName) {
+    this.id = id;
+    this.firstName = firstName;
+    this.lastName = lastName;
+  }
+
+  public String getId() {
+    return id;
+  }
+
+  public String getFirstName() {
+    return firstName;
+  }
+
+  public String getLastName() {
+    return lastName;
+  }
+}
diff --git a/data-transfer-object/src/main/java/com/iluwatar/datatransfer/CustomerResource.java b/data-transfer-object/src/main/java/com/iluwatar/datatransfer/CustomerResource.java
@@ -0,0 +1,63 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Gopinath Langote
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * 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,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.iluwatar.datatransfer;
+
+import java.util.List;
+
+/**
+ * The resource class which serves customer information.
+ * This class act as server in the demo. Which has all customer details.
+ */
+public class CustomerResource {
+  private List<CustomerDto> customers;
+
+  /**
+   * @param customers initialize resource with existing customers. Act as database.
+   */
+  public CustomerResource(List<CustomerDto> customers) {
+    this.customers = customers;
+  }
+
+  /**
+   * @return : all customers in list.
+   */
+  public List<CustomerDto> getAllCustomers() {
+    return customers;
+  }
+
+  /**
+   * @param customer save new customer to list.
+   */
+  public void save(CustomerDto customer) {
+    customers.add(customer);
+  }
+
+  /**
+   * @param customerId delete customer with id {@code customerId}
+   */
+  public void delete(String customerId) {
+    customers.removeIf(customer -> customer.getId().equals(customerId));
+  }
+}
diff --git a/data-transfer-object/src/test/java/com/iluwatar/datatransfer/CustomerResourceTest.java b/data-transfer-object/src/test/java/com/iluwatar/datatransfer/CustomerResourceTest.java
@@ -0,0 +1,81 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Gopinath Langote
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * 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,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.iluwatar.datatransfer;
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * tests {@link CustomerResource}.
+ */
+public class CustomerResourceTest {
+  @Test
+  public void shouldGetAllCustomers() {
+    CustomerDto customer = new CustomerDto("1", "David", "Roy");
+    List<CustomerDto> customers = new ArrayList<>();
+    customers.add(customer);
+
+    CustomerResource customerResource = new CustomerResource(customers);
+
+    List<CustomerDto> allCustomers = customerResource.getAllCustomers();
+
+    assertEquals(allCustomers.size(), 1);
+    assertEquals(allCustomers.get(0).getId(), "1");
+    assertEquals(allCustomers.get(0).getFirstName(), "David");
+    assertEquals(allCustomers.get(0).getLastName(), "Roy");
+  }
+
+  @Test
+  public void shouldSaveCustomer() {
+    CustomerDto customer = new CustomerDto("1", "David", "Roy");
+    CustomerResource customerResource = new CustomerResource(new ArrayList<>());
+
+    customerResource.save(customer);
+
+    List<CustomerDto> allCustomers = customerResource.getAllCustomers();
+    assertEquals(allCustomers.get(0).getId(), "1");
+    assertEquals(allCustomers.get(0).getFirstName(), "David");
+    assertEquals(allCustomers.get(0).getLastName(), "Roy");
+  }
+
+  @Test
+  public void shouldDeleteCustomer() {
+    CustomerDto customer = new CustomerDto("1", "David", "Roy");
+    List<CustomerDto> customers = new ArrayList<>();
+    customers.add(customer);
+
+    CustomerResource customerResource = new CustomerResource(customers);
+
+    customerResource.delete(customer.getId());
+
+    List<CustomerDto> allCustomers = customerResource.getAllCustomers();
+    assertEquals(allCustomers.size(), 0);
+  }
+
+}
