From 057b969be9a259628acfec651238fa435284192e Mon Sep 17 00:00:00 2001
From: Rich <rich@bemindt.com>
Date: Fri, 24 Dec 2021 16:39:23 -0500
Subject: [PATCH 1/2] Code for Hexagonal Architecture article.

---
 hexagonal/pom.xml                             |  8 ++++
 .../baeldung/hexagonal/bo/BusinessLogic.java  | 27 ++++++++++++
 .../java/com/baeldung/hexagonal/dto/User.java | 41 +++++++++++++++++++
 .../factory/UserRepositoryFactory.java        | 23 +++++++++++
 .../repository/FileBasedUserRespository.java  | 22 ++++++++++
 .../hexagonal/repository/UserRepository.java  | 19 +++++++++
 6 files changed, 140 insertions(+)
 create mode 100644 hexagonal/pom.xml
 create mode 100644 hexagonal/src/main/java/com/baeldung/hexagonal/bo/BusinessLogic.java
 create mode 100644 hexagonal/src/main/java/com/baeldung/hexagonal/dto/User.java
 create mode 100644 hexagonal/src/main/java/com/baeldung/hexagonal/factory/UserRepositoryFactory.java
 create mode 100644 hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRespository.java
 create mode 100644 hexagonal/src/main/java/com/baeldung/hexagonal/repository/UserRepository.java

diff --git a/hexagonal/pom.xml b/hexagonal/pom.xml
new file mode 100644
index 000000000000..2cb27a626676
--- /dev/null
+++ b/hexagonal/pom.xml
@@ -0,0 +1,8 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>com.baeldung</groupId>
+  <artifactId>hexagonal</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <name>Hexagonal</name>
+  <description>Hexagonal Architecture</description>
+</project>
\ No newline at end of file
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/bo/BusinessLogic.java b/hexagonal/src/main/java/com/baeldung/hexagonal/bo/BusinessLogic.java
new file mode 100644
index 000000000000..5673aec4e50d
--- /dev/null
+++ b/hexagonal/src/main/java/com/baeldung/hexagonal/bo/BusinessLogic.java
@@ -0,0 +1,27 @@
+/*******************************************************************************
+ *
+ * Copyright 2017-2021, Bemindt Consulting Group, Inc.
+ * 
+ * BusinessLogic.java
+ * rich
+ * Dec 23, 2021
+ * 
+ *******************************************************************************/
+
+package com.baeldung.hexagonal.bo;
+
+import java.util.List;
+
+import com.baeldung.hexagonal.dto.User;
+import com.baeldung.hexagonal.factory.UserRepositoryFactory;
+import com.baeldung.hexagonal.repository.UserRepository;
+
+public class BusinessLogic {
+    public void processUsers() {
+        // Use factory to get an adapter for reading users
+        UserRepository repo = UserRepositoryFactory.getUserRepository();
+        // Get Users 
+        List<User> userList = repo.getUsers();
+        // Perform business logic
+    }
+}
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/dto/User.java b/hexagonal/src/main/java/com/baeldung/hexagonal/dto/User.java
new file mode 100644
index 000000000000..028e04974c85
--- /dev/null
+++ b/hexagonal/src/main/java/com/baeldung/hexagonal/dto/User.java
@@ -0,0 +1,41 @@
+/*******************************************************************************
+ *
+ * Copyright 2017-2021, Bemindt Consulting Group, Inc.
+ * 
+ * User.java
+ * rich
+ * Dec 23, 2021
+ * 
+ *******************************************************************************/
+
+package com.baeldung.hexagonal.dto;
+
+public class User {
+    public int id;
+    public String firstName;
+    public String lastName;
+
+    public int getId() {
+        return id;
+    }
+    
+    public void setId(int id) {
+        this.id = id;
+    }
+    
+    public String getFirstName() {
+        return firstName;
+    }
+    
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+    
+    public String getLastName() {
+        return lastName;
+    }
+    
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+}
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/factory/UserRepositoryFactory.java b/hexagonal/src/main/java/com/baeldung/hexagonal/factory/UserRepositoryFactory.java
new file mode 100644
index 000000000000..404e20dcd4e7
--- /dev/null
+++ b/hexagonal/src/main/java/com/baeldung/hexagonal/factory/UserRepositoryFactory.java
@@ -0,0 +1,23 @@
+/*******************************************************************************
+ *
+ * Copyright 2017-2021, Bemindt Consulting Group, Inc.
+ * 
+ * UserRepositoryFactory.java
+ * rich
+ * Dec 23, 2021
+ * 
+ *******************************************************************************/
+
+package com.baeldung.hexagonal.factory;
+
+import com.baeldung.hexagonal.repository.FileBasedUserRespository;
+import com.baeldung.hexagonal.repository.UserRepository;
+
+public class UserRepositoryFactory {
+    public static UserRepository getUserRepository() {
+        // Here we would implement the logic to determine the type of 
+        // UserRepository to return, presumably based on some configuration 
+        // or environmental setting.
+        return new FileBasedUserRespository();
+    }
+}
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRespository.java b/hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRespository.java
new file mode 100644
index 000000000000..0499b413da49
--- /dev/null
+++ b/hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRespository.java
@@ -0,0 +1,22 @@
+/*******************************************************************************
+ *
+ * Copyright 2017-2021, Bemindt Consulting Group, Inc.
+ * 
+ * FileBasedUserRespository.java
+ * rich
+ * Dec 23, 2021
+ * 
+ *******************************************************************************/
+
+package com.baeldung.hexagonal.repository;
+
+import java.util.List;
+
+import com.baeldung.hexagonal.dto.User;
+
+public class FileBasedUserRespository implements UserRepository {
+
+    public List<User> getUsers() {
+        return null;
+    }
+}
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/repository/UserRepository.java b/hexagonal/src/main/java/com/baeldung/hexagonal/repository/UserRepository.java
new file mode 100644
index 000000000000..2d186c0f69f8
--- /dev/null
+++ b/hexagonal/src/main/java/com/baeldung/hexagonal/repository/UserRepository.java
@@ -0,0 +1,19 @@
+/*******************************************************************************
+ *
+ * Copyright 2017-2021, Bemindt Consulting Group, Inc.
+ * 
+ * UserRepository.java
+ * rich
+ * Dec 23, 2021
+ * 
+ *******************************************************************************/
+
+package com.baeldung.hexagonal.repository;
+
+import java.util.List;
+
+import com.baeldung.hexagonal.dto.User;
+
+public interface UserRepository {
+    public List<User> getUsers();
+}

From 5c52b7944698b93a8f687a822a57c1b7c54ade0c Mon Sep 17 00:00:00 2001
From: Rich <rich@bemindt.com>
Date: Fri, 31 Dec 2021 09:32:58 -0500
Subject: [PATCH 2/2] Updated code and added test cases

---
 .../com/baeldung/hexagonal/Hexagonal.java     | 11 ++++++
 .../baeldung/hexagonal/bo/BusinessLogic.java  | 17 +++------
 .../java/com/baeldung/hexagonal/dto/User.java | 10 -----
 .../hexagonal/factory/RepositoryFactory.java  | 13 +++++++
 .../factory/UserRepositoryFactory.java        | 23 ------------
 .../repository/FileBasedUserRepository.java   | 37 +++++++++++++++++++
 .../repository/FileBasedUserRespository.java  | 22 -----------
 .../hexagonal/repository/UserRepository.java  | 10 -----
 .../factory/RepositoryFactoryTest.java        | 15 ++++++++
 .../FileBasedUserRepositoryTest.java          | 17 +++++++++
 hexagonal/users.csv                           |  4 ++
 11 files changed, 102 insertions(+), 77 deletions(-)
 create mode 100644 hexagonal/src/main/java/com/baeldung/hexagonal/Hexagonal.java
 create mode 100644 hexagonal/src/main/java/com/baeldung/hexagonal/factory/RepositoryFactory.java
 delete mode 100644 hexagonal/src/main/java/com/baeldung/hexagonal/factory/UserRepositoryFactory.java
 create mode 100644 hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRepository.java
 delete mode 100644 hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRespository.java
 create mode 100644 hexagonal/src/test/java/com/baeldung/hexagonal/factory/RepositoryFactoryTest.java
 create mode 100644 hexagonal/src/test/java/com/baeldung/hexagonal/repository/FileBasedUserRepositoryTest.java
 create mode 100644 hexagonal/users.csv

diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/Hexagonal.java b/hexagonal/src/main/java/com/baeldung/hexagonal/Hexagonal.java
new file mode 100644
index 000000000000..5cd19cac2dcd
--- /dev/null
+++ b/hexagonal/src/main/java/com/baeldung/hexagonal/Hexagonal.java
@@ -0,0 +1,11 @@
+package com.baeldung.hexagonal;
+
+import com.baeldung.hexagonal.bo.BusinessLogic;
+
+public class Hexagonal {
+
+    public static void main(String[] args) {
+        BusinessLogic logic = new BusinessLogic();
+        logic.processUsers();
+    }
+}
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/bo/BusinessLogic.java b/hexagonal/src/main/java/com/baeldung/hexagonal/bo/BusinessLogic.java
index 5673aec4e50d..c5d57f271dce 100644
--- a/hexagonal/src/main/java/com/baeldung/hexagonal/bo/BusinessLogic.java
+++ b/hexagonal/src/main/java/com/baeldung/hexagonal/bo/BusinessLogic.java
@@ -1,27 +1,20 @@
-/*******************************************************************************
- *
- * Copyright 2017-2021, Bemindt Consulting Group, Inc.
- * 
- * BusinessLogic.java
- * rich
- * Dec 23, 2021
- * 
- *******************************************************************************/
-
 package com.baeldung.hexagonal.bo;
 
 import java.util.List;
 
 import com.baeldung.hexagonal.dto.User;
-import com.baeldung.hexagonal.factory.UserRepositoryFactory;
+import com.baeldung.hexagonal.factory.RepositoryFactory;
 import com.baeldung.hexagonal.repository.UserRepository;
 
 public class BusinessLogic {
     public void processUsers() {
         // Use factory to get an adapter for reading users
-        UserRepository repo = UserRepositoryFactory.getUserRepository();
+        UserRepository repo = RepositoryFactory.getUserRepository();
         // Get Users 
         List<User> userList = repo.getUsers();
         // Perform business logic
+        userList.forEach(user -> {
+            System.out.println(user.getLastName()+", "+user.getFirstName());
+        });
     }
 }
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/dto/User.java b/hexagonal/src/main/java/com/baeldung/hexagonal/dto/User.java
index 028e04974c85..d73b42b661d4 100644
--- a/hexagonal/src/main/java/com/baeldung/hexagonal/dto/User.java
+++ b/hexagonal/src/main/java/com/baeldung/hexagonal/dto/User.java
@@ -1,13 +1,3 @@
-/*******************************************************************************
- *
- * Copyright 2017-2021, Bemindt Consulting Group, Inc.
- * 
- * User.java
- * rich
- * Dec 23, 2021
- * 
- *******************************************************************************/
-
 package com.baeldung.hexagonal.dto;
 
 public class User {
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/factory/RepositoryFactory.java b/hexagonal/src/main/java/com/baeldung/hexagonal/factory/RepositoryFactory.java
new file mode 100644
index 000000000000..538609689d32
--- /dev/null
+++ b/hexagonal/src/main/java/com/baeldung/hexagonal/factory/RepositoryFactory.java
@@ -0,0 +1,13 @@
+package com.baeldung.hexagonal.factory;
+
+import com.baeldung.hexagonal.repository.FileBasedUserRepository;
+import com.baeldung.hexagonal.repository.UserRepository;
+
+public class RepositoryFactory {
+    public static UserRepository getUserRepository() {
+        // Here we would implement the logic to determine the type of 
+        // UserRepository to return, presumably based on some configuration 
+        // or environmental setting.
+        return new FileBasedUserRepository();
+    }
+}
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/factory/UserRepositoryFactory.java b/hexagonal/src/main/java/com/baeldung/hexagonal/factory/UserRepositoryFactory.java
deleted file mode 100644
index 404e20dcd4e7..000000000000
--- a/hexagonal/src/main/java/com/baeldung/hexagonal/factory/UserRepositoryFactory.java
+++ /dev/null
@@ -1,23 +0,0 @@
-/*******************************************************************************
- *
- * Copyright 2017-2021, Bemindt Consulting Group, Inc.
- * 
- * UserRepositoryFactory.java
- * rich
- * Dec 23, 2021
- * 
- *******************************************************************************/
-
-package com.baeldung.hexagonal.factory;
-
-import com.baeldung.hexagonal.repository.FileBasedUserRespository;
-import com.baeldung.hexagonal.repository.UserRepository;
-
-public class UserRepositoryFactory {
-    public static UserRepository getUserRepository() {
-        // Here we would implement the logic to determine the type of 
-        // UserRepository to return, presumably based on some configuration 
-        // or environmental setting.
-        return new FileBasedUserRespository();
-    }
-}
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRepository.java b/hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRepository.java
new file mode 100644
index 000000000000..59c7de251bb0
--- /dev/null
+++ b/hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRepository.java
@@ -0,0 +1,37 @@
+package com.baeldung.hexagonal.repository;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import com.baeldung.hexagonal.dto.User;
+
+public class FileBasedUserRepository implements UserRepository {
+
+    @Override
+    public List<User> getUsers() {
+        String line = "";  
+        List<User> userList = new ArrayList<>();
+        try   
+        {  
+            //parsing a CSV file into BufferedReader class constructor  
+            BufferedReader br = new BufferedReader(new FileReader("users.csv"));  
+            while ((line = br.readLine()) != null)   //returns a Boolean value  
+            {  
+                String[] userComponents = line.split(",");    // use comma as separator  
+                User user = new User();
+                user.setId(Integer.valueOf(userComponents[0]));
+                user.setFirstName(userComponents[1]);
+                user.setLastName(userComponents[2]);
+                userList.add(user);
+            }  
+            br.close();
+            return userList;
+        } catch (IOException e) {  
+            e.printStackTrace();  
+        }
+        return null;
+    }
+}
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRespository.java b/hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRespository.java
deleted file mode 100644
index 0499b413da49..000000000000
--- a/hexagonal/src/main/java/com/baeldung/hexagonal/repository/FileBasedUserRespository.java
+++ /dev/null
@@ -1,22 +0,0 @@
-/*******************************************************************************
- *
- * Copyright 2017-2021, Bemindt Consulting Group, Inc.
- * 
- * FileBasedUserRespository.java
- * rich
- * Dec 23, 2021
- * 
- *******************************************************************************/
-
-package com.baeldung.hexagonal.repository;
-
-import java.util.List;
-
-import com.baeldung.hexagonal.dto.User;
-
-public class FileBasedUserRespository implements UserRepository {
-
-    public List<User> getUsers() {
-        return null;
-    }
-}
diff --git a/hexagonal/src/main/java/com/baeldung/hexagonal/repository/UserRepository.java b/hexagonal/src/main/java/com/baeldung/hexagonal/repository/UserRepository.java
index 2d186c0f69f8..9173ea0370d1 100644
--- a/hexagonal/src/main/java/com/baeldung/hexagonal/repository/UserRepository.java
+++ b/hexagonal/src/main/java/com/baeldung/hexagonal/repository/UserRepository.java
@@ -1,13 +1,3 @@
-/*******************************************************************************
- *
- * Copyright 2017-2021, Bemindt Consulting Group, Inc.
- * 
- * UserRepository.java
- * rich
- * Dec 23, 2021
- * 
- *******************************************************************************/
-
 package com.baeldung.hexagonal.repository;
 
 import java.util.List;
diff --git a/hexagonal/src/test/java/com/baeldung/hexagonal/factory/RepositoryFactoryTest.java b/hexagonal/src/test/java/com/baeldung/hexagonal/factory/RepositoryFactoryTest.java
new file mode 100644
index 000000000000..969dcd31c32b
--- /dev/null
+++ b/hexagonal/src/test/java/com/baeldung/hexagonal/factory/RepositoryFactoryTest.java
@@ -0,0 +1,15 @@
+package com.baeldung.hexagonal.factory;
+
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.hexagonal.repository.UserRepository;
+
+class RepositoryFactoryTest {
+
+    @Test
+    void test() {
+        UserRepository repo = RepositoryFactory.getUserRepository();
+        assert(repo != null);
+    }
+
+}
diff --git a/hexagonal/src/test/java/com/baeldung/hexagonal/repository/FileBasedUserRepositoryTest.java b/hexagonal/src/test/java/com/baeldung/hexagonal/repository/FileBasedUserRepositoryTest.java
new file mode 100644
index 000000000000..881051d6b92f
--- /dev/null
+++ b/hexagonal/src/test/java/com/baeldung/hexagonal/repository/FileBasedUserRepositoryTest.java
@@ -0,0 +1,17 @@
+package com.baeldung.hexagonal.repository;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.hexagonal.dto.User;
+
+class FileBasedUserRepositoryTest {
+
+    @Test
+    void test() {
+        UserRepository repo = new FileBasedUserRepository();
+        List<User> userList = repo.getUsers();
+        assert(userList != null && userList.size() > 0);
+    }
+}
diff --git a/hexagonal/users.csv b/hexagonal/users.csv
new file mode 100644
index 000000000000..f781ef1d36ad
--- /dev/null
+++ b/hexagonal/users.csv
@@ -0,0 +1,4 @@
+1,Rachel,Grey
+2,Laura,Jenkins
+3,Craig,Booker
+4,Mary,Smith