WS-07-Multithreading-Basics-and-Hashing

.idea/.gitignore

@@ -0,0 +1,10 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Ignored default folder with query files
+/queries/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
+# Editor-based HTTP Client requests
+/httpRequests/

.idea/compiler.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CompilerConfiguration">
+    <annotationProcessing>
+      <profile name="Maven default annotation processors profile" enabled="true">
+        <sourceOutputDir name="target/generated-sources/annotations" />
+        <sourceTestOutputDir name="target/generated-test-sources/test-annotations" />
+        <outputRelativeToContentRoot value="true" />
+        <module name="WS-07-Multithreading-Basics-and-Hashing" />
+      </profile>
+    </annotationProcessing>
+  </component>
+</project>

.idea/encodings.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Encoding">
+    <file url="file://$PROJECT_DIR$/src/main/java" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/src/main/resources" charset="UTF-8" />
+  </component>
+</project>

.idea/jarRepositories.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="RemoteRepositoriesConfiguration">
+    <remote-repository>
+      <option name="id" value="central" />
+      <option name="name" value="Maven Central repository" />
+      <option name="url" value="https://repo1.maven.org/maven2" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="jboss.community" />
+      <option name="name" value="JBoss Community repository" />
+      <option name="url" value="https://repository.jboss.org/nexus/content/repositories/public/" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="central" />
+      <option name="name" value="Central Repository" />
+      <option name="url" value="https://mirror-maven.runflare.com/maven2" />
+    </remote-repository>
+  </component>
+</project>

.idea/misc.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
+  <component name="MavenProjectsManager">
+    <option name="originalFiles">
+      <list>
+        <option value="$PROJECT_DIR$/pom.xml" />
+      </list>
+    </option>
+  </component>
+  <component name="ProjectRootManager" version="2" project-jdk-name="25" project-jdk-type="JavaSDK" />
+</project>

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>

src/main/java/dev/Main.java

@@ -12,18 +12,17 @@ public class Main {
     public static void main(String[] args) throws Exception {
 
         Scanner scanner = new Scanner(System.in);
-
         StudentManager manager = new StudentManager();
 
         while (true) {
+            System.out.println("\n--- Student Search Engine Menu ---");
+            System.out.println("1. Load students");
+            System.out.println("2. Search student");
+            System.out.println("3. Remove student");
+            System.out.println("4. Print all students");
+            System.out.println("5. Exit");
+            System.out.print("Enter your choice: ");
 
-            System.out.println("""
-                    1.Load students
-                    2.Search student
-                    3.Remove student
-                    4.Print students
-                    5.Exit
-                    """);
 
             int choice = scanner.nextInt();
 
@@ -33,32 +32,28 @@ public class Main {
 
                     List<String> data = FileManager.loadStudents("students.txt");
 
-                    // TODO:
+                    int size = data.size();
+                    List<String> part1 = data.subList(0, size/3);
+                    List<String> part2 = data.subList(size/3, (size/3)*2);
+                    List<String> part3 = data.subList((size/3)*2, size);
 
-                    // Split data into 3 parts
+                    StudentLoader t1 = new StudentLoader(part1);
+                    StudentLoader t2 = new StudentLoader(part2);
+                    StudentLoader t3 = new StudentLoader(part3);
 
-                    List<String> part1 = null;
+                    t1.start();
+                    t2.start();
+                    t3.start();
 
-                    List<String> part2 = null;
+                    t1.join();
+                    t2.join();
+                    t3.join();
 
-                    List<String> part3 = null;
+                    manager.addStudents(t1.getStudents());
-
+                    manager.addStudents(t2.getStudents());
-                    // TODO:
+                    manager.addStudents(t3.getStudents());
-
-                    StudentLoader t1 = null;
-
-                    StudentLoader t2 = null;
-
-                    StudentLoader t3 = null;
-
-                    // TODO:
-
-                    // start()
-
-                    // join()
-
-                    // merge results
 
+                    System.out.println("Student loaded successfully.");
                 }
 
                 case 2 -> {

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

@@ -40,33 +40,24 @@ public class Student {
 
     @Override
     public int hashCode() {
-
+         return id % 97;
-        // TODO:
-        // Return custom hash
-
-        // Example:
-        // return id % 97;
-
-        return 0;
     }
 
     @Override
     public boolean equals(Object obj) {
 
-        // TODO:
+        if(obj == null){
-
-        // Step 1:
-        // Check null
-
-        // Step 2:
-        // Convert obj to Student
-
-        // Step 3:
-        // Compare IDs
-
             return false;
         }
 
+        if(getClass() != obj.getClass()){
+            return false;
+        }
+        Student otherStudent = (Student)obj;
+
+        return this.id == otherStudent.id;
+    }
+
     @Override
     public String toString() {
 

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

@@ -4,50 +4,49 @@ import dev.model.Student;
 
 import java.util.ArrayList;
 
-
 public class StudentManager {
 
     private final ArrayList<Student> students = new ArrayList<>();
 
     public void addStudents(ArrayList<Student> newStudents) {
-
+        if(newStudents != null){
-        // TODO:
+            this.students.addAll(newStudents);
-
+        }
-        // Merge students
-
-        // Hint:
-        // addAll()
-
     }
 
     public Student searchStudent(int id) {
-
+        for (Student student : students) {
-        // TODO:
+            if (student.getId() == id){
-
+                return student;
-        // Loop through students
+            }
-
+        }
-        // Compare IDs
-
         return null;
     }
 
     public boolean removeStudent(int id) {
+        Student foundStudent = null;
+        for (Student s : students){
+            if (s.getId() == id){
+                foundStudent = s;
+                break;
+            }
+        }
 
-        // TODO:
+        if (foundStudent != null){
-
+            students.remove(foundStudent);
-        // Find student
+            return true;
-
+        }
-        // Remove student
-
         return false;
     }
 
     public void printStudents() {
+        if (students.isEmpty()) {
+            System.out.println("No students to display.");
+            return;
+        }
 
         for (Student student : students) {
-
             System.out.println(student);
-
         }
 
     }

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

@@ -9,46 +9,38 @@ import java.util.List;
 
 public class StudentLoader extends Thread {
 
-    // Assigned file lines
-
     private final List<String> lines;
 
-    // Local student storage
-
     private final ArrayList<Student> students = new ArrayList<>();
 
-    public StudentLoader(List<String> lines) {
+    public StudentLoader(List<String>lines) {
-
         this.lines = lines;
     }
 
     @Override
     public void run() {
-
-        // TODO:
-
-        /*
-        Example line:
-
-        1001,Aryan,Computer Science,3.7
-         */
-
         for (String line : lines) {
-
+            if(line == null || line.trim().isEmpty()){
-            // TODO:
+                continue;
-            // split line
-
-            // TODO:
-            // read values
-
-            // TODO:
-            // create Student
-
-            // TODO:
-            // add to students list
-
             }
+            String[] parts = line.split(",");
 
+            if(parts.length == 4){
+                try {
+                    int id = Integer.parseInt(parts[0].trim());
+                    String name = parts[1].trim();
+                    String major = parts[2].trim();
+                    double gpa = Double.parseDouble(parts[3].trim());
+
+                    Student student = new Student(id, name, major, gpa);
+                    students.add(student);
+                }catch (Exception e){
+                    System.out.println(e.getMessage());
+                }
+            }else{
+                System.out.println("skipping malformed line: " + line);
+            }
+        }
     }
 
     public ArrayList<Student> getStudents() {

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

@@ -13,20 +13,13 @@ public class FileManager {
         List<String> lines = new ArrayList<>();
 
         BufferedReader reader = new BufferedReader(new FileReader(path));
-
         String line;
-
         while ((line = reader.readLine()) != null) {
-
+            if (!line.trim().isEmpty()) {
-            // TODO:
+                lines.add(line.trim());
-
+            }
-            // Add line to list
-
         }
-
         reader.close();
-
         return lines;
     }
-
 }

src/main/java/lecture/multithreading/timeout/Main.java

@@ -1,10 +1,23 @@
 package lecture.multithreading.timeout;
 
 
+import java.util.Scanner;
 
 public class Main {
     public static void main(String[] args) {
-        // TODO
+        Scanner scanner = new Scanner(System.in);
+
+        System.out.println("you have 10 seconds: ");
+        System.out.println("enter your name: ");
+
+        MyRunnable myRunnable = new MyRunnable();
+        Thread thread = new Thread(myRunnable);
+        thread.setDaemon(true);
+        thread.start();
+
+        String name = scanner.nextLine();
+        System.out.println("Hello " + name);
+        scanner.close();
     }
 }
 

src/main/java/lecture/multithreading/timeout/MyRunnable.java

@@ -0,0 +1,20 @@
+package lecture.multithreading.timeout;
+
+public class MyRunnable implements Runnable{
+
+    @Override
+    public void run() {
+        for (int i = 0; i <= 10; i++) {
+            try {
+                Thread.sleep(1000);
+            } catch (InterruptedException e) {
+                System.out.println("thread was interrupted");
+            }
+
+            if(i==10){
+                System.out.println("time is up");
+                System.exit(0);
+            }
+        }
+    }
+}