Fixes according to comments.

libraries-data/src/main/java/com/baeldung/storm/bolt/FileWritingBolt.java

@@ -22,6 +22,7 @@ public class FileWritingBolt extends BaseRichBolt {
     private BufferedWriter writer;
     private String filePath;
     private ObjectMapper objectMapper;
+
     @Override
     public void prepare(Map map, TopologyContext topologyContext, OutputCollector outputCollector) {
         objectMapper = new ObjectMapper();
@@ -55,6 +56,15 @@ public class FileWritingBolt extends BaseRichBolt {
         this.filePath = filePath;
     }
 
+    @Override
+    public void cleanup() {
+        try {
+            writer.close();
+        } catch (IOException e) {
+            logger.error("Failed to close the writer!");
+        }
+    }
+
     @Override
     public void declareOutputFields(OutputFieldsDeclarer outputFieldsDeclarer) {
 

libraries-data/src/main/java/com/baeldung/storm/spout/RandomNumberSpout.java

@@ -26,7 +26,7 @@ public class RandomNumberSpout extends BaseRichSpout {
     public void nextTuple() {
         Utils.sleep(1000);
         //This will select random int from the range (-1000, 1000)
-        int operation = random.nextInt(1000 + 1 + 1000) - 1000;
+        int operation = random.nextInt(101);
         long timestamp = System.currentTimeMillis();
 
         Values values = new Values(operation, timestamp);