diff --git a/Report.md b/Report.md
new file mode 100644
index 0000000..ad3fa36
--- /dev/null
+++ b/Report.md
@@ -0,0 +1,41 @@
+1:
+ the output is Calling run()
+ Running in: main
+ Calling start()
+ Running in: Thread-2
+
+t1.run() does not start a new thread.
+It just calls the run() method like a normal method call, and it executes on the current thread.
+t2.start() creates a new thread and then that new thread executes run(), so current Thread Name becomes Thread-2.
+
+run() is just a normal method call, so it runs in the current thread.
+
+start() creates a new thread, and that new thread executes run().
+
+2:
+ Output:
+ Main thread ends.
+ It may also print:
+ Daemon thread running…
+ a few times, or sometimes not at all.
+ Why:
+ Because the created thread is a daemon thread. Daemon threads run in the background, and when the main thread finishes, the JVM can stop immediately.
+ So the daemon thread may not complete its loop.
+ If thread.setDaemon(true) is removed:
+ Then the thread becomes a user thread (non-daemon thread).
+ and the JVM will wait for it to finish, so "Daemon thread running..." will print many times until the loops end.
+ Real-life uses of daemon threads:
+ Garbage collection
+ Background auto-save
+ Cache cleanup
+ Monitoring or logging services
+ Timer or scheduler tasks running in background
+3:
+ What output do you get from the program?
+ Thread is running using a …!
+ What is the () -> { ... } syntax called?
+ This is called a lambda expression.
+
+ How is this code different from creating a class that extends Thread or implements Runnable?
+ This is a shorter and cleaner way to write thread code.
+ Instead of creating a separate class, the task is written directly inside the lambda expression.
diff --git a/src/main/java/.idea/.gitignore b/src/main/java/.idea/.gitignore
new file mode 100644
index 0000000..ab1f416
--- /dev/null
+++ b/src/main/java/.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/
diff --git a/src/main/java/.idea/misc.xml b/src/main/java/.idea/misc.xml
new file mode 100644
index 0000000..a20905f
--- /dev/null
+++ b/src/main/java/.idea/misc.xml
@@ -0,0 +1,6 @@
+
+
+
+
+
+
\ No newline at end of file
diff --git a/src/main/java/.idea/modules.xml b/src/main/java/.idea/modules.xml
new file mode 100644
index 0000000..122a905
--- /dev/null
+++ b/src/main/java/.idea/modules.xml
@@ -0,0 +1,8 @@
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/src/main/java/.idea/vcs.xml b/src/main/java/.idea/vcs.xml
new file mode 100644
index 0000000..c2365ab
--- /dev/null
+++ b/src/main/java/.idea/vcs.xml
@@ -0,0 +1,6 @@
+
+
+
+
+
+
\ No newline at end of file
diff --git a/src/main/java/DownloadWorker.java b/src/main/java/DownloadWorker.java
index 546de2d..ccd6620 100644
--- a/src/main/java/DownloadWorker.java
+++ b/src/main/java/DownloadWorker.java
@@ -21,23 +21,33 @@ public class DownloadWorker implements Runnable {
@Override
public void run() {
- // TODO: Record the chunk start time in chunkStatus.
+ chunkStatus.setStartTimeMs(System.currentTimeMillis());
double downloaded = 0.0;
- // TODO: Print a message that this chunk has started downloading.
-
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.
- }
+ try {
+ int delay = config.getMinStepDelayMs()
+ + random.nextInt(config.getMaxStepDelayMs() - config.getMinStepDelayMs() + 1);
+ Thread.sleep(delay);
- // TODO: Mark the chunk as completed.
- // TODO: Record the chunk end time in chunkStatus.
- // TODO: Print a message that this chunk has finished downloading.
+ double stepDownload = config.getMinStepDownloadMB()
+ + random.nextDouble() * (config.getMaxStepDownloadMB() - config.getMinStepDownloadMB());
+
+ downloaded += stepDownload;
+ if (downloaded > chunkStatus.getChunkSizeMB()) {
+ downloaded = chunkStatus.getChunkSizeMB();
+ }
+
+ chunkStatus.setDownloadedMB(downloaded);
+
+ } catch (InterruptedException e) {
+ System.err.println("[Worker-" + chunkStatus.getChunkId() + "] Download interrupted.");
+ Thread.currentThread().interrupt();
+ return;
+ }
+ }
+ chunkStatus.setCompleted(true);
+ chunkStatus.setEndTimeMs(System.currentTimeMillis());
}
}
diff --git a/src/main/java/Main.java b/src/main/java/Main.java
index 82bd239..ba09981 100644
--- a/src/main/java/Main.java
+++ b/src/main/java/Main.java
@@ -34,36 +34,34 @@ 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("Assigned Chunk " + chunk.getChunkId());
}
// 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();
+
+ try {
+ for (Thread thread : workerThreads) {
+ thread.join();
+ }
+ } catch (InterruptedException e) {
+ System.out.println("Interrupted.");
+ return;
+ }
+
+ try {
+ monitorThread.join();
+ } catch (InterruptedException e) {
+ System.out.println("Interrupted.");
+ return;
+ }
- // 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();
- // }
// TODO:
// After all workers finish, the monitor thread may also need to stop.
diff --git a/src/main/java/ProgressMonitor.java b/src/main/java/ProgressMonitor.java
index 475c0e0..7cf598d 100644
--- a/src/main/java/ProgressMonitor.java
+++ b/src/main/java/ProgressMonitor.java
@@ -16,16 +16,7 @@ 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
-
+ long startTimeMs = System.currentTimeMillis();
while (true) {
double totalDownloadedMB = 0.0;
@@ -33,37 +24,72 @@ public class ProgressMonitor implements Runnable {
for (ChunkStatus chunk : chunks) {
totalDownloadedMB += chunk.getDownloadedMB();
-
if (chunk.isCompleted()) {
completedChunks++;
}
}
- double percent = 0.0;
- if (totalSizeMB > 0) {
- percent = (totalDownloadedMB * 100.0) / totalSizeMB;
- }
+ long elapsedMs = System.currentTimeMillis() - startTimeMs;
+ double elapsedSeconds = elapsedMs / 1000.0;
+
+ double speedMBps = elapsedSeconds > 0.0
+ ? totalDownloadedMB / elapsedSeconds
+ : 0.0;
+
+ double percent = totalSizeMB > 0
+ ? totalDownloadedMB * 100.0 / totalSizeMB
+ : 100.0;
+ percent = Math.max(0.0, Math.min(100.0, percent));
+
+ double remainingMB = Math.max(0.0, totalSizeMB - totalDownloadedMB);
+ long etaSeconds = speedMBps > 0.0
+ ? (long) Math.ceil(remainingMB / speedMBps)
+ : 0L;
+
+ int barWidth = 40;
+ int filled = (int) Math.round(percent / 100.0 * barWidth);
+ filled = Math.max(0, Math.min(barWidth, filled));
+
+ String bar = "#".repeat(filled) + "-".repeat(barWidth - filled);
System.out.printf(
- "Progress for %s: %.1f/%.1f MB (%.2f%%), completed chunks: %d/%d%n",
- fileName,
- totalDownloadedMB,
- (double) totalSizeMB,
+ "\r[%s] %6.2f%% %7.1f/%d MB | %6.2f MB/s | ETA %s | chunks %d/%d",
+ bar,
percent,
+ totalDownloadedMB,
+ totalSizeMB,
+ speedMBps,
+ formatEta(etaSeconds),
completedChunks,
chunks.size()
);
+ System.out.flush();
-
- // TODO:
- // If all chunks are completed, print a final message and exit the loop
+ if (completedChunks == chunks.size()) {
+ System.out.println();
+ System.out.println("All chunks completed.");
+ break;
+ }
try {
Thread.sleep(monitorDelayMs);
} catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+ System.out.println();
System.out.println("Progress monitor interrupted.");
return;
}
}
}
+
+ private String formatEta(long totalSeconds) {
+ long minutes = totalSeconds / 60;
+ long seconds = totalSeconds % 60;
+
+ if (minutes > 0) {
+ return String.format("%dm %02ds", minutes, seconds);
+ }
+
+ return String.format("%ds", seconds);
+ }
}