import java.io.*; public class P6 { public static void main(String[] args) throws IOException { String filePath = "P6.in"; StringBuilder content = new StringBuilder(); try (BufferedReader reader = new BufferedReader(new FileReader(filePath))) { String line; while ((line = reader.readLine()) != null) { content.append(line.toUpperCase()).append("\n"); } } try (BufferedWriter writer = new BufferedWriter(new FileWriter(filePath))) { writer.write(content.toString()); } } }