create the FileWriterConsumer class

src/main/java/writer/FileWriterConsumer.java

 package writer;
 
-public class FileWriterConsumer {
+import model.SequencedLine;
+import java.io.BufferedWriter;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.concurrent.PriorityBlockingQueue;
+import java.util.concurrent.atomic.AtomicInteger;
+
+
+public class FileWriterConsumer implements Runnable {
+    private final String outputFilePath;
+    private final PriorityBlockingQueue<SequencedLine> outputQueue;
+    private final AtomicInteger activeConsumers;
+
+    public FileWriterConsumer(String outputFilePath,
+                              PriorityBlockingQueue<SequencedLine> outputQueue,
+                              AtomicInteger activeConsumers) {
+        this.outputFilePath = outputFilePath;
+        this.outputQueue = outputQueue;
+        this.activeConsumers = activeConsumers;
+    }
+
+    @Override
+    public void run() {
+        System.out.println(" Writer started: " + outputFilePath);
+        int writtenCount = 0;
+
+        try (BufferedWriter writer = new BufferedWriter(new FileWriter(outputFilePath))) {
+
+            // Continue writing until all consumers are done and queue is empty
+            while (activeConsumers.get() > 0 || !outputQueue.isEmpty()) {
+                try {
+                    SequencedLine line = outputQueue.take();
+
+                    // Write the line to the output file
+                    writer.write(line.getLine());
+                    writer.newLine();
+                    writtenCount++;
+
+                    // Progress reporting
+                    if (writtenCount % 25 == 0) {
+                        System.out.println(" Writer: " + writtenCount + " lines written (last sequence: " +
+                                line.getSequenceNumber() + ")");
+                    }
+
+                } catch (InterruptedException e) {
+                    System.err.println(" Writer was interrupted while waiting for data");
+                    Thread.currentThread().interrupt();
+                    break;
+                }
+            }
+
+            System.out.println(" Writer finished: " + writtenCount + " lines written in perfect order");
+
+        } catch (IOException e) {
+            System.err.println(" File write error: " + e.getMessage());
+            e.printStackTrace();
+        }
+
+        // Final status report
+        System.out.println(" Writer completed. Final queue size: " + outputQueue.size());
+    }
+
+    public String getOutputFilePath() {
+        return outputFilePath;
+    }
+
+    public int getRemainingQueueSize() {
+        return outputQueue.size();
+    }
 }
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