src/main/java/ChunkStatus.java

@@ -105,4 +105,8 @@ public class ChunkStatus {
                 completed ? " [Completed]" : ""
         );
     }
+
+    public void setStartTime(long startTime) {
+
+    }
 }

src/main/java/DownloadConfig.java

@@ -67,4 +67,10 @@ public class DownloadConfig {
                 ", maxStepDownloadMB=" + maxStepDownloadMB +
                 '}';
     }
+
+    public int getMinDelayMs() {
+    }
+
+    public int getMaxDelayMs() {
+    }
 }

src/main/java/DownloadWorker.java

@@ -21,23 +21,57 @@ public class DownloadWorker implements Runnable {
 
     @Override
     public void run() {
-        // TODO: Record the chunk start time in chunkStatus.
+        long startTime = System.currentTimeMillis();
+        chunkStatus.setStartTime(startTime);
+
         double downloaded = 0.0;
 
-        // TODO: Print a message that this chunk has started downloading.
+        System.out.println("Chunk \"" + chunkStatus.getChunkId() + "\" 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 {
+                //Generate a random sleep delay between min and max delay.
+                int minDelay = config.getMinDelayMs();
+                int maxDelay = config.getMaxDelayMs();
+                int randomDelay = random.nextInt((maxDelay - minDelay) + 1) + minDelay;
+
+                //Sleep for that delay.
+                Thread.sleep(randomDelay);
+
+                //Generate a random download amount for this step.
+                double minStep = config.getMinStepDelayMs();
+                double maxStep = config.getMaxStepDelayMs();
+                double randomStep = (maxStep + minStep)*random.nextDouble() + minStep;
+
+                //Increase downloaded, but do not go beyond chunk size.
+                downloaded += randomStep;
+                if (downloaded > chunkStatus.getChunkSizeMB()) {
+                    downloaded = chunkStatus.getChunkSizeMB();
+                }
+
+                //Save the updated downloaded value into chunkStatus.
+                chunkStatus.setDownloadedMB(downloaded);
+
+                //print step-by-step progress.
+                System.out.printf("Chunk #%d: Downloaded %.2f / %.2f MB%n",
+                        chunkStatus.getChunkId(), downloaded, chunkStatus.getChunkSizeMB());
+
+            } catch (InterruptedException e) {
+                System.out.println("Chunk \"" + chunkStatus.getChunkId() + "\" was interrupted!");
+                return;
+            }
         }
 
-        // TODO: Mark the chunk as completed.
-        // TODO: Record the chunk end time in chunkStatus.
-        // TODO: Print a message that this chunk has finished downloading.
+        //Mark the chunk as completed.
+        chunkStatus.setCompleted(true);
+
+        //Record the chunk end time in chunkStatus.
+        long endTime = System.currentTimeMillis();
+        chunkStatus.setEndTimeMs(endTime);
+
+        //Print a message that this chunk has finished downloading.
+        System.out.println("Chunk \"" + chunkStatus.getChunkId() + "\" has finished downloading.");
     }
 
 }