add Report

.idea/markdown.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="MarkdownSettings">
+    <option name="previewPanelProviderInfo">
+      <ProviderInfo name="Compose (experimental)" className="com.intellij.markdown.compose.preview.ComposePanelProvider" />
+    </option>
+  </component>
+</project>

REPORT.md

@@ -0,0 +1,64 @@
+# Report
+
+## 1. start() vs run()
+
+Output:
+
+```text
+Calling run()
+Running in: main
+Calling start()
+Running in: Thread-2
+```
+
+When `run()` is called directly, it runs like a normal method, so it is executed by the main thread.
+
+When `start()` is called, Java creates a new thread, and then the `run()` method runs inside that new thread. That is why the second output shows `Thread-2`.
+
+So, `run()` does not start a new thread, but `start()` does.
+
+---
+
+
+## 2. Daemon Threads
+
+The output is not always the same. The main thread prints:
+
+```text
+Main thread ends.
+```
+
+and then finishes. Since the created thread is marked as a daemon thread using `setDaemon(true)`, the JVM does not wait for it to complete. As a result, the program may stop before the daemon thread finishes all 20 iterations. Depending on the scheduling, the message
+
+```text
+Daemon thread running...
+```
+
+may appear a few times or may not appear at all.
+
+If `setDaemon(true)` is removed, the thread becomes a normal user thread. In that case, the JVM waits for the thread to finish, and the message
+
+```text
+Daemon thread running...
+```
+
+will be printed 20 times before the program exits.
+
+Daemon threads are commonly used for background tasks such as logging, monitoring, and cleanup operations.
+
+
+
+
+## 3. A shorter way to create threads
+
+Output:
+
+```text
+Thread is running using a ...!
+```
+
+The syntax `() -> { ... }` is called a lambda expression.
+
+It is a shorter way to write a `Runnable`. Instead of creating a separate class or anonymous class, we write the thread task directly inside the `Thread` constructor.
+
+This makes the code shorter and easier to read.

src/main/java/DownloadWorker.java

@@ -1,12 +1,5 @@
 import java.util.Random;
 
-/**
- * Simulates downloading a single chunk of a file.
- *
- * <p>This class is intentionally provided as a skeleton for students.
- * The main multithreading and simulation logic should be completed
- * in the run() method.</p>
- */
 public class DownloadWorker implements Runnable {
 
     private final ChunkStatus chunkStatus;
@@ -21,23 +14,43 @@ public class DownloadWorker implements Runnable {
 
     @Override
     public void run() {
-        // TODO: Record the chunk start time in chunkStatus.
-        double downloaded = 0.0;
+        chunkStatus.setStartTimeMs(System.currentTimeMillis());
 
-        // TODO: Print a message that this chunk has started downloading.
+        double downloaded = 0;
+
+        System.out.println("Chunk " + chunkStatus.getChunkId() + " started.");
 
         while (downloaded < chunkStatus.getChunkSizeMB()) {
-            // TODO: Generate a random sleep delay between min and max delay.
-            // TODO: Sleep for that delay.
-            // TODO: Generate a random download amount for this step.
-            // TODO: Increase downloaded, but do not go beyond chunk size.
-            // TODO: Save the updated downloaded value into chunkStatus.
-            // TODO: Optionally print step-by-step progress.
+
+            int delay = random.nextInt(
+                    config.getMaxStepDelayMs() - config.getMinStepDelayMs() + 1
+            ) + config.getMinStepDelayMs();
+
+            try {
+                Thread.sleep(delay);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+
+            double amount = random.nextDouble() *
+                    (config.getMaxStepDownloadMB() - config.getMinStepDownloadMB())
+                    + config.getMinStepDownloadMB();
+
+            downloaded = downloaded + amount;
+
+            if (downloaded > chunkStatus.getChunkSizeMB()) {
+                downloaded = chunkStatus.getChunkSizeMB();
+            }
+
+            chunkStatus.setDownloadedMB(downloaded);
+
+            System.out.println("Chunk " + chunkStatus.getChunkId()
+                    + ": " + downloaded + "/" + chunkStatus.getChunkSizeMB() + " MB");
         }
 
-        // TODO: Mark the chunk as completed.
-        // TODO: Record the chunk end time in chunkStatus.
-        // TODO: Print a message that this chunk has finished downloading.
-    }
+        chunkStatus.setCompleted(true);
+        chunkStatus.setEndTimeMs(System.currentTimeMillis());
 
+        System.out.println("Chunk " + chunkStatus.getChunkId() + " finished.");
+    }
 }

src/main/java/Main.java

@@ -5,8 +5,8 @@ public class Main {
     public static void main(String[] args) {
         System.out.println("=== Simulated Download Manager ===");
 
-        // 1. Read config
         DownloadConfig config;
+
         try {
             config = ConfigReader.readConfig("download_config.txt");
         } catch (Exception e) {
@@ -19,13 +19,11 @@ public class Main {
         System.out.println("Chunk count: " + config.getChunkCount());
         System.out.println();
 
-        // 2. Create chunks
         List<ChunkStatus> chunks = ChunkUtils.createChunks(
                 config.getTotalSizeMB(),
                 config.getChunkCount()
         );
 
-        // 3. Create worker threads
         List<Thread> workerThreads = new ArrayList<>();
 
         for (ChunkStatus chunk : chunks) {
@@ -34,69 +32,49 @@ public class Main {
 
             workerThreads.add(workerThread);
 
-            // TODO:
-            // Students may print helpful debug information here,
-            // for example which chunk is assigned to which worker thread.
+            System.out.println("Chunk " + chunk.getChunkId()
+                    + " assigned to " + workerThread.getName());
         }
 
-        // 4. Create and start monitor thread
         ProgressMonitor monitor = new ProgressMonitor(config, chunks);
         Thread monitorThread = new Thread(monitor, "Progress-Monitor");
 
-        // TODO:
-        // Start the monitor thread before starting the workers
-        // so that progress can be displayed while downloading happens.
-        //
-        // Example idea:
-        // monitorThread.start();
+        monitorThread.start();
 
-        // 5. Start worker threads
-        // TODO:
-        // Start each worker thread in workerThreads.
-        // Use a loop and call start() on each thread.
+        for (Thread thread : workerThreads) {
+            thread.start();
+        }
 
-        // 6. Wait for workers to finish
-        // TODO:
-        // Wait for all worker threads to complete by calling join().
-        // This should be done inside a try-catch block for InterruptedException.
-        //
-        // Hint:
-        // for (Thread thread : workerThreads) {
-        //     thread.join();
-        // }
+        for (Thread thread : workerThreads) {
+            try {
+                thread.join();
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
 
-        // TODO:
-        // After all workers finish, the monitor thread may also need to stop.
-        // Depending on how ProgressMonitor is implemented, students may:
-        // - wait for it to finish on its own, or
-        // - add a stopping mechanism in ProgressMonitor later.
-        //
-        // If your monitor finishes automatically, you may join it here.
+        try {
+            monitorThread.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
 
-        // NOTE:
-        // this final report may show 0 progress because no worker has actually run yet.
-        // Until students complete the thread start/join TODOs above,
-
-        // 7. Print final report
         System.out.println();
         System.out.println("=== Final Report ===");
 
         int completedChunks = 0;
-        double downloadedMB = 0.0;
+        double downloadedMB = 0;
 
         for (ChunkStatus chunk : chunks) {
-            downloadedMB += chunk.getDownloadedMB();
+            downloadedMB = downloadedMB + chunk.getDownloadedMB();
 
             if (chunk.isCompleted()) {
                 completedChunks++;
             }
 
-            System.out.println(
-                    "Chunk " + chunk.getChunkId()
-                            + ": " + chunk.getDownloadedMB()
-                            + "/" + chunk.getChunkSizeMB()
-                            + " MB"
-            );
+            System.out.println("Chunk " + chunk.getChunkId()
+                    + ": " + chunk.getDownloadedMB()
+                    + "/" + chunk.getChunkSizeMB() + " MB");
         }
 
         System.out.println();

src/main/java/ProgressMonitor.java

@@ -16,53 +16,39 @@ public class ProgressMonitor implements Runnable {
 
     @Override
     public void run() {
-        // TODO:
-        // Repeatedly check chunk progress until all chunks are completed.
-        // In each loop:
-        // 1. Read the downloaded size from every chunk
-        // 2. Add all downloaded amounts to totalDownloadedMB
-        // 3. Count completed chunks
-        // 4. Print a progress message
-        // 5. If completedChunks == chunks.size(), print a final monitor message and stop
-        // 6. Otherwise sleep for monitorDelayMs and continue
-
 
         while (true) {
-            double totalDownloadedMB = 0.0;
+            double totalDownloadedMB = 0;
             int completedChunks = 0;
 
             for (ChunkStatus chunk : chunks) {
-                totalDownloadedMB += chunk.getDownloadedMB();
+                totalDownloadedMB = totalDownloadedMB + chunk.getDownloadedMB();
 
                 if (chunk.isCompleted()) {
                     completedChunks++;
                 }
             }
 
-            double percent = 0.0;
+            double percent = 0;
+
             if (totalSizeMB > 0) {
-                percent = (totalDownloadedMB * 100.0) / totalSizeMB;
+                percent = (totalDownloadedMB * 100) / totalSizeMB;
             }
 
-            System.out.printf(
-                    "Progress for %s: %.1f/%.1f MB (%.2f%%), completed chunks: %d/%d%n",
-                    fileName,
-                    totalDownloadedMB,
-                    (double) totalSizeMB,
-                    percent,
-                    completedChunks,
-                    chunks.size()
-            );
+            System.out.println("Progress for " + fileName + ": "
+                    + totalDownloadedMB + "/" + totalSizeMB
+                    + " MB (" + percent + "%), completed chunks: "
+                    + completedChunks + "/" + chunks.size());
 
-
-            // TODO:
-            // If all chunks are completed, print a final message and exit the loop
+            if (completedChunks == chunks.size()) {
+                System.out.println("Download completed!");
+                break;
+            }
 
             try {
                 Thread.sleep(monitorDelayMs);
             } catch (InterruptedException e) {
-                System.out.println("Progress monitor interrupted.");
-                return;
+                e.printStackTrace();
             }
         }
     }