Inclusion of log4j dependency rather than relying on

System.out.println() statements.
Added unit tests for doa module.

dao/pom.xml

@@ -1,18 +1,28 @@
 <?xml version="1.0"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-  <modelVersion>4.0.0</modelVersion>
-  <parent>
-    <groupId>com.iluwatar</groupId>
-    <artifactId>java-design-patterns</artifactId>
-    <version>1.6.0</version>
-  </parent>
-  <artifactId>dao</artifactId>
-  <dependencies>
-    <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>com.iluwatar</groupId>
+		<artifactId>java-design-patterns</artifactId>
+		<version>1.6.0</version>
+	</parent>
+	<artifactId>dao</artifactId>
+	
+	<properties>
+		
+	</properties>
+	
+	<dependencies>
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>log4j</groupId>
+			<artifactId>log4j</artifactId>
+		</dependency>
+	</dependencies>
 </project>

dao/src/main/java/com/iluwatar/dao/App.java

@@ -3,6 +3,8 @@ package com.iluwatar.dao;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.log4j.Logger;
+
 /**
  * 
  * With the DAO pattern, we can use various method calls to retrieve/add/delete/update data without directly
@@ -11,43 +13,38 @@ import java.util.List;
  */
 public class App {
 
+	private static Logger LOGGER = Logger.getLogger(App.class);
+
 	/**
-	 * Program entry point
-	 * @param args command line args
+	 * Program entry point.
+	 * 
+	 * @param args command line args.
 	 */
-	public static void main(String[] args) {
-
-		CustomerDaoImpl customerDao = new CustomerDaoImpl(generateSampleCustomers());
-
-		System.out.println("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
-		System.out.println("customerDao.getCusterById(2): " + customerDao.getCusterById(2));
-
-		Customer customer = new Customer(4, "Dan", "Danson");
+	public static void main(final String[] args) {
+		final CustomerDaoImpl customerDao = new CustomerDaoImpl(generateSampleCustomers());
+		LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
+		LOGGER.info("customerDao.getCusterById(2): " + customerDao.getCustomerById(2));
+		final Customer customer = new Customer(4, "Dan", "Danson");
 		customerDao.addCustomer(customer);
-
-		System.out.println("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
-
+		LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
 		customer.setFirstName("Daniel");
 		customer.setLastName("Danielson");
 		customerDao.updateCustomer(customer);
-
-		System.out.println("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
-
+		LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
 		customerDao.deleteCustomer(customer);
-
-		System.out.println("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
+		LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
 	}
 
 	/**
-	 * Generate customers
-	 * @return list of customers
+	 * Generate customers.
+	 * 
+	 * @return list of customers.
 	 */
 	public static List<Customer> generateSampleCustomers() {
-		Customer customer1 = new Customer(1, "Adam", "Adamson");
-		Customer customer2 = new Customer(2, "Bob", "Bobson");
-		Customer customer3 = new Customer(3, "Carl", "Carlson");
-
-		List<Customer> customers = new ArrayList<Customer>();
+		final Customer customer1 = new Customer(1, "Adam", "Adamson");
+		final Customer customer2 = new Customer(2, "Bob", "Bobson");
+		final Customer customer3 = new Customer(3, "Carl", "Carlson");
+		final List<Customer> customers = new ArrayList<Customer>();
 		customers.add(customer1);
 		customers.add(customer2);
 		customers.add(customer3);

dao/src/main/java/com/iluwatar/dao/Customer.java

@@ -11,7 +11,7 @@ public class Customer {
     private String firstName;
     private String lastName;
 
-    public Customer(int id, String firstName, String lastName) {
+    public Customer(final int id, final String firstName, final String lastName) {
         this.id = id;
         this.firstName = firstName;
         this.lastName = lastName;
@@ -21,7 +21,7 @@ public class Customer {
         return id;
     }
 
-    public void setId(int id) {
+    public void setId(final int id) {
         this.id = id;
     }
 
@@ -29,7 +29,7 @@ public class Customer {
         return firstName;
     }
 
-    public void setFirstName(String firstName) {
+    public void setFirstName(final String firstName) {
         this.firstName = firstName;
     }
 
@@ -37,34 +37,39 @@ public class Customer {
         return lastName;
     }
 
-    public void setLastName(String lastName) {
+    public void setLastName(final String lastName) {
         this.lastName = lastName;
     }
 
     @Override
     public String toString() {
         return "Customer{" +
-                "id=" + id +
-                ", firstName='" + firstName + '\'' +
-                ", lastName='" + lastName + '\'' +
+                "id=" + getId() +
+                ", firstName='" + getFirstName() + '\'' +
+                ", lastName='" + getLastName() + '\'' +
                 '}';
     }
 
+    /**
+     * Checks if two objects are the same.
+     * 
+     * @return true if the two objects are Customer objects and have the same id value, false otherwise.
+     */
     @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-
-        Customer customer = (Customer) o;
-
-        if (id != customer.id) return false;
-
-        return true;
+    public boolean equals(final Object o) {
+    	boolean isEqual = false;
+    	final Customer customer = (Customer) o;
+        if (getId() == customer.getId()) {
+        	isEqual = true;
+        }
+        return isEqual;
     }
-
+    
     @Override
     public int hashCode() {
-        int result = id;
+        int result = getId();
+        id += getFirstName().hashCode();
+        id += getLastName().hashCode();
         return result;
     }
 }

dao/src/main/java/com/iluwatar/dao/CustomerDao.java

@@ -9,9 +9,9 @@ import java.util.List;
  */
 public interface CustomerDao {
 	
-    public List<Customer> getAllCustomers();
-    public Customer getCusterById(int id);
-    public void addCustomer(Customer customer);
-    public void updateCustomer(Customer customer);
-    public void deleteCustomer(Customer customer);
+    List<Customer> getAllCustomers();
+    Customer getCustomerById(final int id);
+    void addCustomer(final Customer customer);
+    void updateCustomer(final Customer customer);
+    void deleteCustomer(final Customer customer);
 }

dao/src/main/java/com/iluwatar/dao/CustomerDaoImpl.java

@@ -17,7 +17,7 @@ public class CustomerDaoImpl implements CustomerDao {
     // Note: Normally this would be in the form of an actual database and not part of the Dao Impl.
     private List<Customer> customers;
 
-    public CustomerDaoImpl(List<Customer> customers) {
+    public CustomerDaoImpl(final List<Customer> customers) {
         this.customers = customers;
     }
 
@@ -27,31 +27,33 @@ public class CustomerDaoImpl implements CustomerDao {
     }
 
     @Override
-    public Customer getCusterById(int id) {
-        for (int i = 0; i < customers.size(); i++) {
-            if (customers.get(i).getId() == id) {
-                return customers.get(i);
+    public Customer getCustomerById(final int id) {
+    	Customer customer = null;
+        for (final Customer cus : getAllCustomers()) {
+            if (cus.getId() == id) {
+                customer = cus;
+                break;
             }
         }
-        // No customer found
-        return null;
+        return customer;
     }
 
     @Override
-    public void addCustomer(Customer customer) {
+    public void addCustomer(final Customer customer) {
         customers.add(customer);
     }
 
 
     @Override
-    public void updateCustomer(Customer customer) {
-        if (customers.contains(customer)) {
-            customers.set(customers.indexOf(customer), customer);
+    public void updateCustomer(final Customer customer) {
+        if (getAllCustomers().contains(customer)) {
+        	final int index = getAllCustomers().indexOf(customer);
+            getAllCustomers().set(index, customer);
         }
     }
 
     @Override
-    public void deleteCustomer(Customer customer) {
-        customers.remove(customer);
+    public void deleteCustomer(final Customer customer) {
+        getAllCustomers().remove(customer);
     }
 }

dao/src/test/java/com/iluwatar/dao/AppTest.java

@@ -1,19 +0,0 @@
-package com.iluwatar.dao;
-
-import org.junit.Test;
-
-import com.iluwatar.dao.App;
-
-/**
- * 
- * Application test
- *
- */
-public class AppTest {
-
-	@Test
-	public void test() {
-		String[] args = {};
-		App.main(args);
-	}
-}

dao/src/test/java/com/iluwatar/dao/CustomerDaoImplTest.java

@@ -0,0 +1,81 @@
+package com.iluwatar.dao;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class CustomerDaoImplTest {
+
+	private CustomerDaoImpl impl;
+	private List<Customer> customers;
+	private static final Customer CUSTOMER = new Customer(1, "Freddy", "Kruger");
+	
+	@Before
+	public void setUp() {
+		customers = new ArrayList<Customer>();
+		customers.add(CUSTOMER);
+		impl = new CustomerDaoImpl(customers);
+	}
+	
+	@Test
+	public void deleteExistingCustomer() {
+		assertEquals(1, impl.getAllCustomers().size());
+		impl.deleteCustomer(CUSTOMER);
+		assertTrue(impl.getAllCustomers().isEmpty());
+	}
+	
+	@Test
+	public void deleteNonExistingCustomer() {
+		final Customer nonExistingCustomer = new Customer(2, "Robert", "Englund");
+		impl.deleteCustomer(nonExistingCustomer);
+		assertEquals(1, impl.getAllCustomers().size());
+	}
+	
+	@Test
+	public void updateExistingCustomer() {
+		final String newFirstname = "Bernard";
+		final String newLastname = "Montgomery";
+		final Customer customer = new Customer(CUSTOMER.getId(), newFirstname, newLastname);
+		impl.updateCustomer(customer);
+		final Customer cust = impl.getCustomerById(CUSTOMER.getId());
+		assertEquals(newFirstname, cust.getFirstName());
+		assertEquals(newLastname, cust.getLastName());
+	}
+	
+	@Test
+	public void updateNonExistingCustomer() {
+		final int nonExistingId = 999;
+		final String newFirstname = "Douglas";
+		final String newLastname = "MacArthur";
+		final Customer customer = new Customer(nonExistingId, newFirstname, newLastname);
+		impl.updateCustomer(customer);
+		assertNull(impl.getCustomerById(nonExistingId));
+		final Customer existingCustomer = impl.getCustomerById(CUSTOMER.getId());
+		assertEquals(CUSTOMER.getFirstName(), existingCustomer.getFirstName());
+		assertEquals(CUSTOMER.getLastName(), existingCustomer.getLastName());
+	}
+	
+	@Test
+	public void addCustomer() {
+		final Customer newCustomer = new Customer(3, "George", "Patton");
+		impl.addCustomer(newCustomer);
+		assertEquals(2, impl.getAllCustomers().size());
+	}
+	
+	@Test
+	public void getExistinCustomerById() {
+		assertEquals(CUSTOMER, impl.getCustomerById(CUSTOMER.getId()));
+	}
+	
+	@Test
+	public void getNonExistinCustomerById() {
+		final int nonExistingId = 999;
+		assertNull(impl.getCustomerById(nonExistingId));
+	}
+}

dao/src/test/java/com/iluwatar/dao/CustomerTest.java

@@ -0,0 +1,87 @@
+package com.iluwatar.dao;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class CustomerTest {
+
+	private Customer customer;
+	private static final int ID = 1;
+	private static final String FIRSTNAME = "Winston";
+	private static final String LASTNAME = "Churchill";
+	
+	@Before
+	public void setUp() {
+		customer = new Customer(ID, FIRSTNAME, LASTNAME);
+	}
+	
+	@Test
+	public void getIndex() {
+		assertEquals(ID, customer.getId());
+	}
+	
+	@Test
+	public void getFirstname() {
+		assertEquals(FIRSTNAME, customer.getFirstName());
+	}
+	
+	@Test
+	public void getLastname() {
+		assertEquals(LASTNAME, customer.getLastName());
+	}
+	
+	@Test
+	public void setIndex() {
+		final int newId = 2;
+		customer.setId(newId);
+		assertEquals(newId, customer.getId());
+	}
+	
+	@Test
+	public void setFirstname() {
+		final String newFirstname = "Bill";
+		customer.setFirstName(newFirstname);
+		assertEquals(newFirstname, customer.getFirstName());
+	}
+	
+	@Test
+	public void setLastname() {
+		final String newLastname = "Clinton";
+		customer.setLastName(newLastname);
+		assertEquals(newLastname, customer.getLastName());
+	}
+	
+	@Test
+	public void equalsWithDifferentId() {
+		final int newId = 2;
+		final Customer otherCustomer = new Customer(newId, FIRSTNAME, LASTNAME);
+		assertFalse(customer.equals(otherCustomer));
+	}
+	
+	@Test
+	public void equalsWithSameObjects() {
+		final Customer otherCustomer = new Customer(ID, FIRSTNAME, LASTNAME);
+		assertTrue(customer.equals(otherCustomer));
+	}
+	
+	@Test
+	public void testHashCode() {
+		assertTrue(customer.hashCode() > 0);
+	}
+	
+	@Test
+	public void testToString() {
+		final StringBuffer buffer = new StringBuffer();
+		buffer.append("Customer{id=");
+        buffer.append(""+customer.getId());
+        buffer.append(", firstName='");
+        buffer.append(customer.getFirstName());
+        buffer.append("\', lastName='");
+        buffer.append(customer.getLastName() + "\'}");
+		assertEquals(buffer.toString(), customer.toString());
+	}
+}

dao/src/test/resources/log4j.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
+<log4j:configuration debug="true"
+	xmlns:log4j='http://jakarta.apache.org/log4j/'>
+
+	<appender name="console" class="org.apache.log4j.ConsoleAppender">
+		<layout class="org.apache.log4j.PatternLayout">
+			<param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" />
+		</layout>
+	</appender>
+
+	<root>
+		<level value="INFO" />
+		<appender-ref ref="console" />
+	</root>
+
+</log4j:configuration>

pom.xml

@@ -18,6 +18,7 @@
 		<jacoco.version>0.7.2.201409121644</jacoco.version>
 		<commons-dbcp.version>1.4</commons-dbcp.version>
 		<camel.version>2.15.3</camel.version>
+		<log4j.version>1.2.17</log4j.version>
 	</properties>
 	<modules>
 		<module>abstract-factory</module>
@@ -122,6 +123,11 @@
 				<version>${junit.version}</version>
 				<scope>test</scope>
 			</dependency>
+			<dependency>
+				<groupId>log4j</groupId>
+				<artifactId>log4j</artifactId>
+				<version>${log4j.version}</version>
+			</dependency>
 		</dependencies>
 	</dependencyManagement>