Resolves checkstyle errors for converter, cqrs (#1063)

* Reduces checkstyle errors in converter

* Reduces checkstyle errors in cqrs

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

@@ -23,12 +23,10 @@
 
 package com.iluwatar.converter;
 
-
+import java.util.List;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.List;
-
 /**
  * The Converter pattern is a behavioral design pattern which allows a common way of bidirectional
  * conversion between corresponding types (e.g. DTO and domain representations of the logically
@@ -38,8 +36,9 @@ import java.util.List;
 public class App {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
+
   /**
-   * Program entry point
+   * Program entry point.
    *
    * @param args command line args
    */

converter/src/main/java/com/iluwatar/converter/Converter.java

@@ -30,8 +30,9 @@ import java.util.stream.Collectors;
 
 /**
  * Generic converter, thanks to Java8 features not only provides a way of generic bidirectional
- * conversion between corresponding types, but also a common way of converting a collection of objects
+ * conversion between corresponding types, but also a common way of converting a collection of
- * of the same type, reducing boilerplate code to the absolute minimum.
+ * objects of the same type, reducing boilerplate code to the absolute minimum.
+ *
  * @param <T> DTO representation's type
  * @param <U> Domain representation's type
  */
@@ -41,6 +42,8 @@ public class Converter<T, U> {
   private final Function<U, T> fromEntity;
 
   /**
+   * Constructor.
+   *
    * @param fromDto    Function that converts given dto entity into the domain entity.
    * @param fromEntity Function that converts given domain entity into the dto entity.
    */
@@ -50,34 +53,44 @@ public class Converter<T, U> {
   }
 
   /**
+   * Converts DTO to Entity.
+   *
    * @param dto DTO entity
-   * @return The domain representation - the result of the converting function application on dto entity.
+   * @return The domain representation - the result of the converting function application on dto
+   *     entity.
    */
   public final U convertFromDto(final T dto) {
     return fromDto.apply(dto);
   }
 
   /**
+   * Converts Entity to DTO.
+   *
    * @param entity domain entity
-   * @return The DTO representation - the result of the converting function application on domain entity.
+   * @return The DTO representation - the result of the converting function application on domain
+   *     entity.
    */
   public final T convertFromEntity(final U entity) {
     return fromEntity.apply(entity);
   }
 
   /**
+   * Converts list of DTOs to list of Entities.
+   *
    * @param dtos collection of DTO entities
-   * @return List of domain representation of provided entities retrieved by
+   * @return List of domain representation of provided entities retrieved by mapping each of them
-   *        mapping each of them with the conversion function
+   *     with the conversion function
    */
   public final List<U> createFromDtos(final Collection<T> dtos) {
     return dtos.stream().map(this::convertFromDto).collect(Collectors.toList());
   }
 
   /**
+   * Converts list of Entities to list of DTOs.
+   *
    * @param entities collection of domain entities
-   * @return List of domain representation of provided entities retrieved by
+   * @return List of domain representation of provided entities retrieved by mapping each of them
-   *        mapping each of them with the conversion function
+   *     with the conversion function
    */
   public final List<T> createFromEntities(final Collection<U> entities) {
     return entities.stream().map(this::convertFromEntity).collect(Collectors.toList());

converter/src/main/java/com/iluwatar/converter/User.java

@@ -26,7 +26,7 @@ package com.iluwatar.converter;
 import java.util.Objects;
 
 /**
- * User class
+ * User class.
  */
 public class User {
   private String firstName;
@@ -35,6 +35,8 @@ public class User {
   private String userId;
 
   /**
+   * Constructor.
+   *
    * @param firstName user's first name
    * @param lastName  user's last name
    * @param isActive  flag indicating whether the user is active
@@ -63,7 +65,8 @@ public class User {
     return userId;
   }
 
-  @Override public boolean equals(Object o) {
+  @Override
+  public boolean equals(Object o) {
     if (this == o) {
       return true;
     }
@@ -75,11 +78,13 @@ public class User {
         .equals(lastName, user.lastName) && Objects.equals(userId, user.userId);
   }
 
-  @Override public int hashCode() {
+  @Override
+  public int hashCode() {
     return Objects.hash(firstName, lastName, isActive, userId);
   }
 
-  @Override public String toString() {
+  @Override
+  public String toString() {
     return "User{" + "firstName='" + firstName + '\'' + ", lastName='" + lastName + '\''
         + ", isActive=" + isActive + ", userId='" + userId + '\'' + '}';
   }

converter/src/main/java/com/iluwatar/converter/UserDto.java

@@ -23,11 +23,10 @@
 
 package com.iluwatar.converter;
 
-
 import java.util.Objects;
 
 /**
- * User DTO class
+ * User DTO class.
  */
 public class UserDto {
 
@@ -37,6 +36,8 @@ public class UserDto {
   private String email;
 
   /**
+   * Constructor.
+   *
    * @param firstName user's first name
    * @param lastName  user's last name
    * @param isActive  flag indicating whether the user is active
@@ -65,7 +66,8 @@ public class UserDto {
     return email;
   }
 
-  @Override public boolean equals(Object o) {
+  @Override
+  public boolean equals(Object o) {
     if (this == o) {
       return true;
     }
@@ -77,11 +79,13 @@ public class UserDto {
         .equals(lastName, userDto.lastName) && Objects.equals(email, userDto.email);
   }
 
-  @Override public int hashCode() {
+  @Override
+  public int hashCode() {
     return Objects.hash(firstName, lastName, isActive, email);
   }
 
-  @Override public String toString() {
+  @Override
+  public String toString() {
     return "UserDto{" + "firstName='" + firstName + '\'' + ", lastName='" + lastName + '\''
         + ", isActive=" + isActive + ", email='" + email + '\'' + '}';
   }

cqrs/src/main/java/com/iluwatar/cqrs/app/App.java

@@ -23,12 +23,6 @@
 
 package com.iluwatar.cqrs.app;
 
-import java.math.BigInteger;
-import java.util.List;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import com.iluwatar.cqrs.commandes.CommandServiceImpl;
 import com.iluwatar.cqrs.commandes.ICommandService;
 import com.iluwatar.cqrs.constants.AppConstants;
@@ -37,32 +31,35 @@ import com.iluwatar.cqrs.dto.Book;
 import com.iluwatar.cqrs.queries.IQueryService;
 import com.iluwatar.cqrs.queries.QueryServiceImpl;
 import com.iluwatar.cqrs.util.HibernateUtil;
+import java.math.BigInteger;
+import java.util.List;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
- * CQRS : Command Query Responsibility Segregation. A pattern used to separate query services from commands or writes
+ * CQRS : Command Query Responsibility Segregation. A pattern used to separate query services from
- * services. The pattern is very simple but it has many consequences. For example, it can be used to tackle down a
+ * commands or writes services. The pattern is very simple but it has many consequences. For
- * complex domain, or to use other architectures that were hard to implement with the classical way.
+ * example, it can be used to tackle down a complex domain, or to use other architectures that were
- * 
+ * hard to implement with the classical way.
- * This implementation is an example of managing books and authors in a library. The persistence of books and authors is
- * done according to the CQRS architecture. A command side that deals with a data model to persist(insert,update,delete)
- * objects to a database. And a query side that uses native queries to get data from the database and return objects as
- * DTOs (Data transfer Objects).
  *
+ * <p>This implementation is an example of managing books and authors in a library. The persistence
+ * of books and authors is done according to the CQRS architecture. A command side that deals with a
+ * data model to persist(insert,update,delete) objects to a database. And a query side that uses
+ * native queries to get data from the database and return objects as DTOs (Data transfer Objects).
  */
 public class App {
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
 
   /**
-   * Program entry point
+   * Program entry point.
    *
-   * @param args
+   * @param args command line args
-   *          command line args
    */
   public static void main(String[] args) {
     ICommandService commands = new CommandServiceImpl();
 
     // Create Authors and Books using CommandService
-    commands.authorCreated(AppConstants.E_EVANS, "Eric Evans", "eEvans@email.com");
+    commands.authorCreated(AppConstants.E_EVANS, "Eric Evans", "evans@email.com");
     commands.authorCreated(AppConstants.J_BLOCH, "Joshua Bloch", "jBloch@email.com");
     commands.authorCreated(AppConstants.M_FOWLER, "Martin Fowler", "mFowler@email.com");
 
@@ -70,7 +67,8 @@ public class App {
     commands.bookAddedToAuthor("Effective Java", 40.54, AppConstants.J_BLOCH);
     commands.bookAddedToAuthor("Java Puzzlers", 39.99, AppConstants.J_BLOCH);
     commands.bookAddedToAuthor("Java Concurrency in Practice", 29.40, AppConstants.J_BLOCH);
-    commands.bookAddedToAuthor("Patterns of Enterprise Application Architecture", 54.01, AppConstants.M_FOWLER);
+    commands.bookAddedToAuthor("Patterns of Enterprise"
+        + " Application Architecture", 54.01, AppConstants.M_FOWLER);
     commands.bookAddedToAuthor("Domain Specific Languages", 48.89, AppConstants.M_FOWLER);
     commands.authorNameUpdated(AppConstants.E_EVANS, "Eric J. Evans");
 
@@ -78,18 +76,18 @@ public class App {
 
     // Query the database using QueryService
     Author nullAuthor = queries.getAuthorByUsername("username");
-    Author eEvans = queries.getAuthorByUsername(AppConstants.E_EVANS);
+    Author evans = queries.getAuthorByUsername(AppConstants.E_EVANS);
-    BigInteger jBlochBooksCount = queries.getAuthorBooksCount(AppConstants.J_BLOCH);
+    BigInteger blochBooksCount = queries.getAuthorBooksCount(AppConstants.J_BLOCH);
     BigInteger authorsCount = queries.getAuthorsCount();
     Book dddBook = queries.getBook("Domain-Driven Design");
-    List<Book> jBlochBooks = queries.getAuthorBooks(AppConstants.J_BLOCH);
+    List<Book> blochBooks = queries.getAuthorBooks(AppConstants.J_BLOCH);
 
     LOGGER.info("Author username : {}", nullAuthor);
-    LOGGER.info("Author eEvans : {}", eEvans);
+    LOGGER.info("Author evans : {}", evans);
-    LOGGER.info("jBloch number of books : {}", jBlochBooksCount);
+    LOGGER.info("jBloch number of books : {}", blochBooksCount);
     LOGGER.info("Number of authors : {}", authorsCount);
     LOGGER.info("DDD book : {}", dddBook);
-    LOGGER.info("jBloch books : {}", jBlochBooks);
+    LOGGER.info("jBloch books : {}", blochBooks);
 
     HibernateUtil.getSessionFactory().close();
   }

cqrs/src/main/java/com/iluwatar/cqrs/commandes/CommandServiceImpl.java

@@ -23,17 +23,16 @@
 
 package com.iluwatar.cqrs.commandes;
 
+import com.iluwatar.cqrs.domain.model.Author;
+import com.iluwatar.cqrs.domain.model.Book;
+import com.iluwatar.cqrs.util.HibernateUtil;
 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 
-import com.iluwatar.cqrs.domain.model.Author;
-import com.iluwatar.cqrs.domain.model.Book;
-import com.iluwatar.cqrs.util.HibernateUtil;
-
 /**
- * This class is an implementation of {@link ICommandService} interface. It uses Hibernate as an api for persistence.
+ * This class is an implementation of {@link ICommandService} interface. It uses Hibernate as an api
- *
+ * for persistence.
  */
 public class CommandServiceImpl implements ICommandService {
 

cqrs/src/main/java/com/iluwatar/cqrs/commandes/ICommandService.java

@@ -24,8 +24,7 @@
 package com.iluwatar.cqrs.commandes;
 
 /**
- * This interface represents the commands of the CQRS pattern
+ * This interface represents the commands of the CQRS pattern.
- *
  */
 public interface ICommandService {
 

cqrs/src/main/java/com/iluwatar/cqrs/constants/AppConstants.java

@@ -24,9 +24,7 @@
 package com.iluwatar.cqrs.constants;
 
 /**
- * 
+ * Class to define the constants.
- * Class to define the constants
- *
  */
 public class AppConstants {
 

cqrs/src/main/java/com/iluwatar/cqrs/domain/model/Author.java

@@ -30,7 +30,6 @@ import javax.persistence.Id;
 
 /**
  * This is an Author entity. It is used by Hibernate for persistence.
- *
  */
 @Entity
 public class Author {
@@ -42,13 +41,11 @@ public class Author {
   private String email;
 
   /**
+   * Constructor.
    *
-   * @param username
+   * @param username username of the author
-   *          username of the author
+   * @param name     name of the author
-   * @param name
+   * @param email    email of the author
-   *          name of the author
-   * @param email
-   *          email of the author
    */
   public Author(String username, String name, String email) {
     this.username = username;

cqrs/src/main/java/com/iluwatar/cqrs/domain/model/Book.java

@@ -30,8 +30,8 @@ import javax.persistence.Id;
 import javax.persistence.ManyToOne;
 
 /**
- * This is a Book entity. It is used by Hibernate for persistence. Many books can be written by one {@link Author}
+ * This is a Book entity. It is used by Hibernate for persistence. Many books can be written by one
- *
+ * {@link Author}
  */
 @Entity
 public class Book {
@@ -44,13 +44,11 @@ public class Book {
   private Author author;
 
   /**
+   * Constructor.
    *
-   * @param title
+   * @param title  title of the book
-   *          title of the book
+   * @param price  price of the book
-   * @param price
+   * @param author author of the book
-   *          price of the book
-   * @param author
-   *          author of the book
    */
   public Book(String title, double price, Author author) {
     this.title = title;

cqrs/src/main/java/com/iluwatar/cqrs/dto/Author.java

@@ -26,9 +26,7 @@ package com.iluwatar.cqrs.dto;
 import java.util.Objects;
 
 /**
- * 
+ * This is a DTO (Data Transfer Object) author, contains only useful information to be returned.
- * This is a DTO (Data Transfer Object) author, contains only useful information to be returned
- *
  */
 public class Author {
 
@@ -37,13 +35,11 @@ public class Author {
   private String username;
 
   /**
+   * Constructor.
    *
-   * @param name
+   * @param name     name of the author
-   *          name of the author
+   * @param email    email of the author
-   * @param email
+   * @param username username of the author
-   *          email of the author
-   * @param username
-   *          username of the author
    */
   public Author(String name, String email, String username) {
     this.name = name;
@@ -85,7 +81,8 @@ public class Author {
       return false;
     }
     Author other = (Author) obj;
-    return username.equals(other.getUsername()) && email.equals(other.getEmail()) && name.equals(other.getName());
+    return username.equals(other.getUsername()) && email.equals(other.getEmail()) && name
+        .equals(other.getName());
 
   }
 

cqrs/src/main/java/com/iluwatar/cqrs/dto/Book.java

@@ -26,9 +26,7 @@ package com.iluwatar.cqrs.dto;
 import java.util.Objects;
 
 /**
- * 
+ * This is a DTO (Data Transfer Object) book, contains only useful information to be returned.
- * This is a DTO (Data Transfer Object) book, contains only useful information to be returned
- *
  */
 public class Book {
 
@@ -36,11 +34,10 @@ public class Book {
   private double price;
 
   /**
+   * Constructor.
    *
-   * @param title
+   * @param title title of the book
-   *          title of the book
+   * @param price price of the book
-   * @param price
-   *          price of the book
    */
   public Book(String title, double price) {
     this.title = title;

cqrs/src/main/java/com/iluwatar/cqrs/queries/IQueryService.java

@@ -23,16 +23,13 @@
 
 package com.iluwatar.cqrs.queries;
 
+import com.iluwatar.cqrs.dto.Author;
+import com.iluwatar.cqrs.dto.Book;
 import java.math.BigInteger;
 import java.util.List;
 
-import com.iluwatar.cqrs.dto.Author;
-import com.iluwatar.cqrs.dto.Book;
-
 /**
- * 
+ * This interface represents the query methods of the CQRS pattern.
- * This interface represents the query methods of the CQRS pattern
- *
  */
 public interface IQueryService {
 

cqrs/src/main/java/com/iluwatar/cqrs/queries/QueryServiceImpl.java

@@ -23,23 +23,20 @@
 
 package com.iluwatar.cqrs.queries;
 
+import com.iluwatar.cqrs.constants.AppConstants;
+import com.iluwatar.cqrs.dto.Author;
+import com.iluwatar.cqrs.dto.Book;
+import com.iluwatar.cqrs.util.HibernateUtil;
 import java.math.BigInteger;
 import java.util.List;
-
 import org.hibernate.SQLQuery;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.transform.Transformers;
 
-import com.iluwatar.cqrs.constants.AppConstants;
-import com.iluwatar.cqrs.dto.Author;
-import com.iluwatar.cqrs.dto.Book;
-import com.iluwatar.cqrs.util.HibernateUtil;
-
 /**
- * This class is an implementation of {@link IQueryService}. It uses Hibernate native queries to return DTOs from the
+ * This class is an implementation of {@link IQueryService}. It uses Hibernate native queries to
- * database.
+ * return DTOs from the database.
- *
  */
 public class QueryServiceImpl implements IQueryService {
 
@@ -49,11 +46,12 @@ public class QueryServiceImpl implements IQueryService {
   public Author getAuthorByUsername(String username) {
     Author authorDTo = null;
     try (Session session = sessionFactory.openSession()) {
-      SQLQuery sqlQuery = session
+      SQLQuery sqlQuery = session.createSQLQuery("SELECT a.username as \"username\","
-          .createSQLQuery("SELECT a.username as \"username\", a.name as \"name\", a.email as \"email\""
+          + " a.name as \"name\", a.email as \"email\""
           + "FROM Author a where a.username=:username");
       sqlQuery.setParameter(AppConstants.USER_NAME, username);
-      authorDTo = (Author) sqlQuery.setResultTransformer(Transformers.aliasToBean(Author.class)).uniqueResult();
+      authorDTo = (Author) sqlQuery.setResultTransformer(Transformers.aliasToBean(Author.class))
+          .uniqueResult();
     }
     return authorDTo;
   }
@@ -62,10 +60,11 @@ public class QueryServiceImpl implements IQueryService {
   public Book getBook(String title) {
     Book bookDTo = null;
     try (Session session = sessionFactory.openSession()) {
-      SQLQuery sqlQuery = session
+      SQLQuery sqlQuery = session.createSQLQuery("SELECT b.title as \"title\","
-          .createSQLQuery("SELECT b.title as \"title\", b.price as \"price\"" + " FROM Book b where b.title=:title");
+          + " b.price as \"price\"" + " FROM Book b where b.title=:title");
       sqlQuery.setParameter("title", title);
-      bookDTo = (Book) sqlQuery.setResultTransformer(Transformers.aliasToBean(Book.class)).uniqueResult();
+      bookDTo =
+          (Book) sqlQuery.setResultTransformer(Transformers.aliasToBean(Book.class)).uniqueResult();
     }
     return bookDTo;
   }
@@ -87,7 +86,8 @@ public class QueryServiceImpl implements IQueryService {
     BigInteger bookcount = null;
     try (Session session = sessionFactory.openSession()) {
       SQLQuery sqlQuery = session.createSQLQuery(
-          "SELECT count(b.title)" + " FROM  Book b, Author a where b.author_id = a.id and a.username=:username");
+          "SELECT count(b.title)" + " FROM  Book b, Author a"
+              + " where b.author_id = a.id and a.username=:username");
       sqlQuery.setParameter(AppConstants.USER_NAME, username);
       bookcount = (BigInteger) sqlQuery.uniqueResult();
     }

cqrs/src/main/java/com/iluwatar/cqrs/util/HibernateUtil.java

@@ -31,8 +31,8 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * This class simply returns one instance of {@link SessionFactory} initialized when the application is started
+ * This class simply returns one instance of {@link SessionFactory} initialized when the application
- *
+ * is started.
  */
 public class HibernateUtil {
 
@@ -42,7 +42,8 @@ public class HibernateUtil {
   private static SessionFactory buildSessionFactory() {
 
     // configures settings from hibernate.cfg.xml
-    final StandardServiceRegistry registry = new StandardServiceRegistryBuilder().configure().build();
+    final StandardServiceRegistry registry =
+        new StandardServiceRegistryBuilder().configure().build();
     try {
       return new MetadataSources(registry).buildMetadata().buildSessionFactory();
     } catch (Exception ex) {