Implement download worker

src/java/DownloadWorker.java

@@ -0,0 +1,66 @@
+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;
+    private final DownloadConfig config;
+    private final Random random;
+
+    public DownloadWorker(ChunkStatus chunkStatus, DownloadConfig config) {
+        this.chunkStatus = chunkStatus;
+        this.config = config;
+        this.random = new Random();
+    }
+
+    @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.
+        System.out.println(Thread.currentThread().getName() + " started downloading Chunk #" + chunkStatus.getChunkId());
+
+        while (downloaded < chunkStatus.getChunkSizeMB()) {
+            // TODO: Generate a random sleep delay between min and max delay.
+            int minDelay = config.getMinStepDelayMs() ;
+            int maxDelay = config.getMaxStepDalayMs() ;
+            int delay = minDelay + random.nextInt(maxDelay-minDelay +1) ;
+
+            // TODO: Sleep for that delay.
+            Thread.sleep(delay) ;
+            // TODO: Generate a random download amount for this step.
+            double minStep = config.getMinStepDownloadMB() ;
+            double maxStep = config.getMaxStepDownloadMB() ;
+            double stepDownload = minStep +  ((maxStep-minStep)*random.nextDouble()) ;
+
+
+            // TODO: Increase downloaded, but do not go beyond chunk size.
+            downloaded += stepDownload ;
+            if (downloaded > chunkStatus.getChunkSizeMB())
+            {
+                downloaded  = chunkStatus.getChunkSizeMB() ;
+            }
+
+            // TODO: Save the updated downloaded value into chunkStatus.
+                chunkStatus.setDownloadedMB(downloaded) ;
+            // TODO: Optionally print step-by-step progress.
+        }
+
+
+        // TODO: Mark the chunk as completed.
+        chunkStatus.setCompleted(true );
+        // TODO: Record the chunk end time in chunkStatus.
+        chunkStatus.setEndTimeMs(System.currentTimeMillis()) ;
+        // TODO: Print a message that this chunk has finished downloading.
+        System.out.println(Thread.currentThread().getName() + " finished downloading Chunk #" + chunkStatus.getChunkId());
+    }
+
+}