Added docker-compose for mongo db. MongoDb db work fixed.

caching/docker-compose.yml

@@ -0,0 +1,11 @@
+version: '3.7'
+services:
+  mongodb_container:
+    image: mongo:latest
+    environment:
+      MONGO_INITDB_ROOT_USERNAME: root
+      MONGO_INITDB_ROOT_PASSWORD: rootpassword
+    ports:
+      - 27017:27017
+    volumes:
+      - ./mongo-data/:/data/db

caching/pom.xml

@@ -39,19 +39,21 @@
       <scope>test</scope>
     </dependency>
     <dependency>
-      <groupId>org.mongodb</groupId>
-      <artifactId>mongodb-driver</artifactId>
-      <version>3.12.1</version>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-junit-jupiter</artifactId>
+      <version>3.12.4</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-all</artifactId>
+      <version>1.10.19</version>
+      <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.mongodb</groupId>
-      <artifactId>mongodb-driver-core</artifactId>
-      <version>3.0.4</version>
-    </dependency>
-    <dependency>
-      <groupId>org.mongodb</groupId>
-      <artifactId>bson</artifactId>
-      <version>3.0.4</version>
+      <artifactId>mongo-java-driver</artifactId>
+      <version>3.4.1</version>
     </dependency>
   </dependencies>
   <!--

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

@@ -65,6 +65,7 @@ public class App {
 
   /**
    * Constructor of current App.
+   *
    * @param isMongo boolean
    */
   public App(final boolean isMongo) {
@@ -97,6 +98,7 @@ public class App {
 
   /**
    * Check the input parameters. if
+   *
    * @param args input params
    * @return true if there is "--mongo" parameter in arguments
    */

caching/src/main/java/com/iluwatar/caching/AppManager.java

@@ -24,10 +24,9 @@
 package com.iluwatar.caching;
 
 import com.iluwatar.caching.database.DbManager;
-import com.iluwatar.caching.database.exceptions.DatabaseConnectionException;
+
 import java.util.Optional;
 
-import lombok.Data;
 import lombok.extern.slf4j.Slf4j;
 
 /**
@@ -39,7 +38,6 @@ import lombok.extern.slf4j.Slf4j;
  * appropriate function in the CacheStore class.
  */
 @Slf4j
-@Data
 public class AppManager {
   /**
    * Caching Policy.
@@ -56,6 +54,7 @@ public class AppManager {
 
   /**
    * Constructor.
+   *
    * @param newDbManager database manager
    */
   public AppManager(final DbManager newDbManager) {
@@ -69,15 +68,12 @@ public class AppManager {
    * to (temporarily) store the data/objects during runtime.
    */
   public void initDb() {
-    try {
     dbManager.connect();
-    } catch (DatabaseConnectionException e) {
-      LOGGER.error("Could not connect to DB: {}", e.getMessage());
-    }
   }
 
   /**
    * Initialize caching policy.
+   *
    * @param policy is a {@link CachingPolicy}
    */
   public void initCachingPolicy(final CachingPolicy policy) {
@@ -90,6 +86,7 @@ public class AppManager {
 
   /**
    * Find user account.
+   *
    * @param userId String
    * @return {@link UserAccount}
    */
@@ -108,6 +105,7 @@ public class AppManager {
 
   /**
    * Save user account.
+   *
    * @param userAccount {@link UserAccount}
    */
   public void save(final UserAccount userAccount) {
@@ -125,6 +123,7 @@ public class AppManager {
 
   /**
    * Returns String.
+   *
    * @return String
    */
   public String printCacheContent() {
@@ -133,6 +132,7 @@ public class AppManager {
 
   /**
    * Cache-Aside save user account helper.
+   *
    * @param userAccount {@link UserAccount}
    */
   private void saveAside(final UserAccount userAccount) {
@@ -142,6 +142,7 @@ public class AppManager {
 
   /**
    * Cache-Aside find user account helper.
+   *
    * @param userId String
    * @return {@link UserAccount}
    */

caching/src/main/java/com/iluwatar/caching/CacheStore.java

@@ -166,6 +166,7 @@ public class CacheStore {
         .map(LruCache::getCacheDataInListForm)
         .orElse(List.of())
         .forEach(dbManager::updateDb);
+    dbManager.disconnect();
   }
 
   /**

caching/src/main/java/com/iluwatar/caching/UserAccount.java

@@ -24,17 +24,17 @@
 package com.iluwatar.caching;
 
 import lombok.AllArgsConstructor;
-import lombok.Getter;
-import lombok.Setter;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
 import lombok.ToString;
 
 /**
  * Entity class (stored in cache and DB) used in the application.
  */
-@Setter
-@Getter
+@Data
 @AllArgsConstructor
 @ToString
+@EqualsAndHashCode
 public class UserAccount {
   /**
    * User Id.

caching/src/main/java/com/iluwatar/caching/database/DbManager.java

@@ -1,7 +1,6 @@
 package com.iluwatar.caching.database;
 
 import com.iluwatar.caching.UserAccount;
-import com.iluwatar.caching.database.exceptions.DatabaseConnectionException;
 
 /**
  * <p>DBManager handles the communication with the underlying data store i.e.
@@ -12,10 +11,16 @@ public interface DbManager {
   /**
    * Connect to DB.
    */
-  void connect() throws DatabaseConnectionException;
+  void connect();
+
+  /**
+   * Disconnect from DB.
+   */
+  void disconnect();
 
   /**
    * Read from DB.
+   *
    * @param userId {@link String}
    * @return {@link UserAccount}
    */
@@ -23,6 +28,7 @@ public interface DbManager {
 
   /**
    * Write to DB.
+   *
    * @param userAccount {@link UserAccount}
    * @return {@link UserAccount}
    */
@@ -30,6 +36,7 @@ public interface DbManager {
 
   /**
    * Update record.
+   *
    * @param userAccount {@link UserAccount}
    * @return {@link UserAccount}
    */
@@ -37,6 +44,7 @@ public interface DbManager {
 
   /**
    * Update record or Insert if not exists.
+   *
    * @param userAccount {@link UserAccount}
    * @return {@link UserAccount}
    */

caching/src/main/java/com/iluwatar/caching/database/MongoDb.java

@@ -7,10 +7,13 @@ import static com.iluwatar.caching.constants.CachingConstants.USER_NAME;
 
 import com.iluwatar.caching.UserAccount;
 import com.iluwatar.caching.constants.CachingConstants;
-import com.iluwatar.caching.database.exceptions.DatabaseConnectionException;
 import com.mongodb.MongoClient;
+import com.mongodb.MongoClientOptions;
+import com.mongodb.MongoCredential;
+import com.mongodb.ServerAddress;
 import com.mongodb.client.MongoDatabase;
 import com.mongodb.client.model.UpdateOptions;
+import java.util.List;
 import lombok.extern.slf4j.Slf4j;
 import org.bson.Document;
 
@@ -20,18 +23,28 @@ import org.bson.Document;
  */
 @Slf4j
 public class MongoDb implements DbManager {
-  private static final String DATABASE_NAME = "test";
+  private static final String DATABASE_NAME = "admin";
+  private static final String MONGO_USER = "root";
+  private static final String MONGO_PASSWORD = "rootpassword";
+  private MongoClient client;
+  private MongoDatabase db;
 
   /**
    * Connect to Db. Check th connection
    */
   @Override
-  public void connect() throws DatabaseConnectionException {
-    try (MongoClient mongoClient = new MongoClient()) {
-      mongoClient.getDatabase("test");
-    } catch (NoClassDefFoundError e) {
-      throw new DatabaseConnectionException("Could not connect to DB.");
+  public void connect() {
+    MongoCredential mongoCredential = MongoCredential.createCredential(MONGO_USER,
+                    DATABASE_NAME,
+                    MONGO_PASSWORD.toCharArray());
+    MongoClientOptions options = MongoClientOptions.builder().build();
+    client = new MongoClient(new ServerAddress(), List.of(mongoCredential), options);
+    db = client.getDatabase(DATABASE_NAME);
   }
+
+  @Override
+  public void disconnect() {
+    client.close();
   }
 
   /**
@@ -42,8 +55,6 @@ public class MongoDb implements DbManager {
    */
   @Override
   public UserAccount readFromDb(final String userId) {
-    try (MongoClient mongoClient = new MongoClient()) {
-      MongoDatabase db = mongoClient.getDatabase(DATABASE_NAME);
     var iterable = db
             .getCollection(CachingConstants.USER_ACCOUNT)
             .find(new Document(USER_ID, userId));
@@ -59,7 +70,6 @@ public class MongoDb implements DbManager {
       return null;
     }
   }
-  }
 
   /**
    * Write data to DB.
@@ -69,8 +79,6 @@ public class MongoDb implements DbManager {
    */
   @Override
   public UserAccount writeToDb(final UserAccount userAccount) {
-    try (MongoClient mongoClient = new MongoClient()) {
-      MongoDatabase db = mongoClient.getDatabase(DATABASE_NAME);
     db.getCollection(USER_ACCOUNT).insertOne(
             new Document(USER_ID, userAccount.getUserId())
                     .append(USER_NAME, userAccount.getUserName())
@@ -78,7 +86,6 @@ public class MongoDb implements DbManager {
     );
     return userAccount;
   }
-  }
 
   /**
    * Update DB.
@@ -88,8 +95,6 @@ public class MongoDb implements DbManager {
    */
   @Override
   public UserAccount updateDb(final UserAccount userAccount) {
-    try (MongoClient mongoClient = new MongoClient()) {
-      MongoDatabase db = mongoClient.getDatabase(DATABASE_NAME);
     Document id = new Document(USER_ID, userAccount.getUserId());
     Document dataSet = new Document(USER_NAME, userAccount.getUserName())
             .append(ADD_INFO, userAccount.getAdditionalInfo());
@@ -97,7 +102,6 @@ public class MongoDb implements DbManager {
             .updateOne(id, new Document("$set", dataSet));
     return userAccount;
   }
-  }
 
   /**
    * Update data if exists.
@@ -107,8 +111,6 @@ public class MongoDb implements DbManager {
    */
   @Override
   public UserAccount upsertDb(final UserAccount userAccount) {
-    try (MongoClient mongoClient = new MongoClient()) {
-      MongoDatabase db = mongoClient.getDatabase(DATABASE_NAME);
     String userId = userAccount.getUserId();
     String userName = userAccount.getUserName();
     String additionalInfo = userAccount.getAdditionalInfo();
@@ -123,5 +125,4 @@ public class MongoDb implements DbManager {
     );
     return userAccount;
   }
-  }
 }

caching/src/main/java/com/iluwatar/caching/database/VirtualDb.java

@@ -23,6 +23,11 @@ public class VirtualDb implements DbManager {
     db = new HashMap<>();
   }
 
+  @Override
+  public void disconnect() {
+    db = null;
+  }
+
   /**
    * Read from Db.
    *

caching/src/main/java/com/iluwatar/caching/database/exceptions/DatabaseConnectionException.java

@@ -1,7 +0,0 @@
-package com.iluwatar.caching.database.exceptions;
-
-public class DatabaseConnectionException extends Exception {
-  public DatabaseConnectionException(String s) {
-    super(s);
-  }
-}