Develop

.gitignore

@@ -1,3 +1,5 @@
 .idea/*
 *.iml
 target/*
+logs/
+*.log

pom.xml

@@ -15,6 +15,7 @@
         <maven.checkstyle.plugin.configLocation>
             https://raw.githubusercontent.com/mate-academy/style-guides/master/java/checkstyle.xml
         </maven.checkstyle.plugin.configLocation>
+        <log4j.version>2.20.0</log4j.version>
     </properties>
 
     <dependencies>
@@ -24,6 +25,17 @@
             <version>4.12</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.apache.logging.log4j</groupId>
+            <artifactId>log4j-api</artifactId>
+            <version>${log4j.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.logging.log4j</groupId>
+            <artifactId>log4j-core</artifactId>
+            <version>${log4j.version}</version>
+        </dependency>
     </dependencies>
     <build>
         <plugins>

src/main/java/mate/academy/Main.java

@@ -6,18 +6,30 @@
 import mate.academy.service.AuthenticationServiceImpl;
 import mate.academy.service.OrderService;
 import mate.academy.service.OrderServiceImpl;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 public class Main {
+    private static final Logger logger =
+            LogManager.getLogger(Main.class);
+
     public static void main(String[] args) {
-        AuthenticationService authenticationService = new AuthenticationServiceImpl();
+        AuthenticationService authenticationService =
+                new AuthenticationServiceImpl();
+
         User user;
+
         try {
             user = authenticationService.login("bob", "1234");
         } catch (AuthenticationException e) {
-            e.printStackTrace();
+            logger.error("Authentication failed for user bob", e);
             return;
         }
+
         OrderService orderService = new OrderServiceImpl();
+
         orderService.completeOrder(user.getUserId());
+
+        logger.info("Program finished successfully");
     }
 }

src/main/java/mate/academy/model/Order.java

@@ -1,8 +1,12 @@
 package mate.academy.model;
 
 import java.util.List;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 public class Order {
+    private static final Logger logger =
+            LogManager.getLogger(Order.class);
     private Long orderId;
     private List<Product> products;
     private Long userId; // the identifier of user who complete the order

src/main/java/mate/academy/model/Product.java

@@ -1,8 +1,12 @@
 package mate.academy.model;
 
 import java.math.BigDecimal;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 public class Product {
+    private static final Logger logger =
+            LogManager.getLogger(Product.class);
     private String title;
     private BigDecimal price;
 

src/main/java/mate/academy/model/User.java

@@ -1,6 +1,11 @@
 package mate.academy.model;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
 public class User {
+    private static final Logger logger =
+            LogManager.getLogger(User.class);
     private Long userId;
     private String login;
     private String password;

src/main/java/mate/academy/service/OrderServiceImpl.java

@@ -4,27 +4,46 @@
 import java.util.List;
 import mate.academy.model.Order;
 import mate.academy.model.Product;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 public class OrderServiceImpl implements OrderService {
+    private static final Logger logger =
+            LogManager.getLogger(OrderServiceImpl.class);
+
     @Override
     public Order completeOrder(Long userId) {
-        // TODO: add log message about method completeOrder was called
+        logger.info("Method completeOrder was called. User id: {}", userId);
+
         List<Product> products = getAllProductsFromShoppingCart(userId);
+
         Order order = new Order(products, userId);
+
         // NOTE: In production ready code this order identifier should be generated by DB
         // For test purpose we simplify this and return dummy data
         order.setOrderId(1L);
+
+        logger.info("Order {} was completed for user {}",
+                order.getOrderId(), userId);
+
         return order;
     }
 
     private List<Product> getAllProductsFromShoppingCart(Long userId) {
+        logger.info("Fetching products from shopping cart for user {}",
+                userId);
+
         // NOTE: In production ready code this method should fetch data from DB
         // For test purpose we simplify this method and return dummy data
         Product iphone = new Product("iPhone X", BigDecimal.valueOf(1199));
         Product macBook = new Product("MacBook Air 2020", BigDecimal.valueOf(1399));
         Product xiaomi = new Product("Xiaomi 12", BigDecimal.valueOf(499));
+
         List<Product> products = List.of(iphone, macBook, xiaomi);
-        // TODO: add log message about successful fetched data from DB
+
+        logger.info("Successfully fetched {} products from DB for user {}",
+                products.size(), userId);
+
         return products;
     }
 }

src/main/resources/log4j2.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="INFO">
+
+    <Appenders>
+
+        <Console name="ConsoleAppender" target="SYSTEM_OUT">
+            <PatternLayout
+                    pattern="%d{yyyy-MM-dd HH:mm:ss} %-5level %logger{36} - %msg%n"/>
+        </Console>
+
+        <File name="FileAppender" fileName="logs/app.log">
+            <PatternLayout
+                    pattern="%d{yyyy-MM-dd HH:mm:ss} %-5level %logger{36} - %msg%n"/>
+        </File>
+
+    </Appenders>
+
+    <Loggers>
+        <Root level="info">
+            <AppenderRef ref="ConsoleAppender"/>
+            <AppenderRef ref="FileAppender"/>
+        </Root>
+    </Loggers>
+
+</Configuration>