WS 07

src/main/java/dev/Main.java

@@ -1,9 +1,11 @@
 package dev;
 
+import dev.model.Student;
 import dev.service.StudentManager;
 import dev.thread.StudentLoader;
 import dev.utils.FileManager;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Scanner;
 
@@ -37,28 +39,56 @@ public class Main {
 
                     // Split data into 3 parts
 
-                    List<String> part1 = null;
+                    int sp1;
+                    switch (data.size() % 3) {
+                        case 1: {
+                            sp1 = (data.size()-1)/3;
+                            break;
+                        }
+                        case 2: {
+                            sp1 = (data.size()-2)/3;
+                            break;
+                        }
+                        default: {
+                            sp1 = data.size()/3;
+                            break;
+                        }
+                    }
+                    int sp2 = sp1 * 2;
 
-                    List<String> part2 = null;
+                    List<String> part1 = data.subList(0, sp1);
 
-                    List<String> part3 = null;
+                    List<String> part2 = data.subList(sp1, sp2);
+
+                    List<String> part3 = data.subList(sp2, data.size());
 
                     // TODO:
 
-                    StudentLoader t1 = null;
+                    StudentLoader t1 = new StudentLoader(part1);
 
-                    StudentLoader t2 = null;
+                    StudentLoader t2 = new StudentLoader(part2);
 
-                    StudentLoader t3 = null;
+                    StudentLoader t3 = new StudentLoader(part3);
 
                     // TODO:
 
                     // start()
 
+                    t3.start();
+                    t2.start();
+                    t1.start();
+
                     // join()
 
+                    t3.join();
+                    t2.join();
+                    t1.join();
+
                     // merge results
 
+                    manager.addStudents(t1.getStudents());
+                    manager.addStudents(t2.getStudents());
+                    manager.addStudents(t3.getStudents());
                 }
 
                 case 2 -> {
@@ -79,7 +109,12 @@ public class Main {
 
                     boolean removed = manager.removeStudent(id);
 
-                    System.out.println(removed);
+                    String res = "The student with id: " + id;
+
+                    if (removed) res += "is removed successfully. ";
+                    else res += "is not found. ";
+
+                    System.out.println(res);
 
                 }
 

src/main/java/dev/model/Student.java

@@ -45,9 +45,7 @@ public class Student {
         // Return custom hash
 
         // Example:
-        // return id % 97;
-
-        return 0;
+        return id % 97;
     }
 
     @Override
@@ -64,7 +62,11 @@ public class Student {
         // Step 3:
         // Compare IDs
 
-        return false;
+        if (obj == this) return true;
+        if (obj == null || obj.getClass() != getClass()) return false;
+
+        Student student = (Student) obj;
+        return student.getId() == id;
     }
 
     @Override

src/main/java/dev/service/StudentManager.java

@@ -2,6 +2,7 @@ package dev.service;
 
 import dev.model.Student;
 
+import java.sql.Struct;
 import java.util.ArrayList;
 
 
@@ -18,6 +19,7 @@ public class StudentManager {
         // Hint:
         // addAll()
 
+        students.addAll(newStudents);
     }
 
     public Student searchStudent(int id) {
@@ -28,6 +30,12 @@ public class StudentManager {
 
         // Compare IDs
 
+        for (Student student : students) {
+            if (student.getId() == id) {
+                return student;
+            }
+        }
+
         return null;
     }
 
@@ -39,6 +47,13 @@ public class StudentManager {
 
         // Remove student
 
+        for (Student student : students) {
+            if (student.getId() == id) {
+                students.remove(student);
+                return true;
+            }
+        }
+
         return false;
     }
 

src/main/java/dev/thread/StudentLoader.java

@@ -47,6 +47,21 @@ public class StudentLoader extends Thread {
             // TODO:
             // add to students list
 
+            String[] data = line.split(",");
+
+            try {
+                int id = Integer.parseInt(data[0]);
+                String name = data[1];
+                String major = data[2];
+                double gpa = Double.parseDouble(data[3]);
+
+                Student student = new Student(id, name, major, gpa);
+
+                students.add(student);
+            }
+            catch (Exception e) {
+                //...
+            }
         }
 
     }

src/main/java/dev/utils/FileManager.java

@@ -22,6 +22,8 @@ public class FileManager {
 
             // Add line to list
 
+            lines.add(line);
+
         }
 
         reader.close();