Use local variable type inference (#995)

* "visitor" pattern: Use local variable type inference

Update "visitor" pattern with local variable type inference.

* "value-object" pattern: Use local variable type inference

Update "value-object" pattern with local variable type inference.

* "unit-of-work" pattern: Use local variable type inference

Update "value-object" pattern with local variable type inference.

* "typeobjectpattern" pattern: Use local variable type inference

Update "value-object" pattern with local variable type inference.

unit-of-work/src/main/java/com/iluwatar/unitofwork/App.java

@@ -34,13 +34,13 @@ public class App {
    * @param args no argument sent
    */
   public static void main(String[] args) {
-    Student ram = new Student(1, "Ram", "Street 9, Cupertino");
-    Student shyam = new Student(2, "Shyam", "Z bridge, Pune");
-    Student gopi = new Student(3, "Gopi", "Street 10, Mumbai");
+    var ram = new Student(1, "Ram", "Street 9, Cupertino");
+    var shyam = new Student(2, "Shyam", "Z bridge, Pune");
+    var gopi = new Student(3, "Gopi", "Street 10, Mumbai");
 
     HashMap<String, List<Student>> context = new HashMap<>();
-    StudentDatabase studentDatabase = new StudentDatabase();
-    StudentRepository studentRepository = new StudentRepository(context, studentDatabase);
+    var studentDatabase = new StudentDatabase();
+    var studentRepository = new StudentRepository(context, studentDatabase);
 
     studentRepository.registerNew(ram);
     studentRepository.registerModified(shyam);

unit-of-work/src/main/java/com/iluwatar/unitofwork/StudentRepository.java

@@ -68,7 +68,7 @@ public class StudentRepository implements IUnitOfWork<Student> {
   }
 
   private void register(Student student, String operation) {
-    List<Student> studentsToOperate = context.get(operation);
+    var studentsToOperate = context.get(operation);
     if (studentsToOperate == null) {
       studentsToOperate = new ArrayList<>();
     }
@@ -99,24 +99,24 @@ public class StudentRepository implements IUnitOfWork<Student> {
   }
 
   private void commitInsert() {
-    List<Student> studentsToBeInserted = context.get(IUnitOfWork.INSERT);
-    for (Student student : studentsToBeInserted) {
+    var studentsToBeInserted = context.get(IUnitOfWork.INSERT);
+    for (var student : studentsToBeInserted) {
       LOGGER.info("Saving {} to database.", student.getName());
       studentDatabase.insert(student);
     }
   }
 
   private void commitModify() {
-    List<Student> modifiedStudents = context.get(IUnitOfWork.MODIFY);
-    for (Student student : modifiedStudents) {
+    var modifiedStudents = context.get(IUnitOfWork.MODIFY);
+    for (var student : modifiedStudents) {
       LOGGER.info("Modifying {} to database.", student.getName());
       studentDatabase.modify(student);
     }
   }
 
   private void commitDelete() {
-    List<Student> deletedStudents = context.get(IUnitOfWork.DELETE);
-    for (Student student : deletedStudents) {
+    var deletedStudents = context.get(IUnitOfWork.DELETE);
+    for (var student : deletedStudents) {
       LOGGER.info("Deleting {} to database.", student.getName());
       studentDatabase.delete(student);
     }

unit-of-work/src/test/java/com/iluwatar/unitofwork/StudentRepositoryTest.java

@@ -97,7 +97,7 @@ public class StudentRepositoryTest {
 
   @Test
   public void shouldNotWriteToDbIfContextIsNull() {
-    StudentRepository studentRepository = new StudentRepository(null, studentDatabase);
+    var studentRepository = new StudentRepository(null, studentDatabase);
 
     studentRepository.commit();
 
@@ -106,7 +106,7 @@ public class StudentRepositoryTest {
 
   @Test
   public void shouldNotWriteToDbIfNothingToCommit() {
-    StudentRepository studentRepository = new StudentRepository(new HashMap<>(), studentDatabase);
+    var studentRepository = new StudentRepository(new HashMap<>(), studentDatabase);
 
     studentRepository.commit();