1. import java.io.BufferedReader;
  2. import java.io.FileReader;
  3. import java.io.IOException;
  4. import java.util.concurrent.Executors;
  5. import java.util.concurrent.ScheduledExecutorService;
  6. import java.util.concurrent.TimeUnit;
  8. public class FileContentMonitor {
  10. private final String filePath;
  11. private String previousContent = null;
  12. private final int checkIntervalSeconds;
  14. public FileContentMonitor(String filePath, int checkIntervalSeconds) {
  15. this.filePath = filePath;
  16. this.checkIntervalSeconds = checkIntervalSeconds;
  17. }
  19. public void startMonitoring() {
  20. ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
  21. scheduler.scheduleAtFixedRate(this::checkFileContent, 0, checkIntervalSeconds, TimeUnit.SECONDS);
  22. }
  24. private void checkFileContent() {
  25. try {
  26. String currentContent = readWholeFile(filePath);
  28. if (currentContent != null && !currentContent.equals(previousContent)) {
  29. System.out.println("File content changed: " + currentContent);
  30. previousContent = currentContent;
  31. }
  32. } catch (IOException e) {
  33. System.err.println("Error reading file: " + e.getMessage());
  34. // Handle potential errors, e.g., file not found, permission issues
  35. // Consider logging the error.
  36. }
  37. }
  39. private String readWholeFile(String filePath) throws IOException {
  40. BufferedReader reader = null;
  41. StringBuilder sb = new StringBuilder();
  43. try {
  44. reader = new BufferedReader(new FileReader(filePath));
  45. String line;
  46. while ((line = reader.readLine()) != null) {
  47. sb.append(line).append(System.lineSeparator()); // Preserve line breaks
  48. }
  49. } finally {
  50. if (reader != null) {
  51. try {
  52. reader.close();
  53. } catch (IOException e) {
  54. System.err.println("Error closing file reader: " + e.getMessage());
  55. }
  56. }
  57. }
  59. return sb.toString();
  60. }
  62. public static void main(String[] args) {
  63. // Example Usage:
  64. String filePath = "test.txt"; // Replace with your file path
  65. int checkInterval = 5; // Check every 5 seconds
  67. // Create a dummy file for testing
  68. try {
  69. java.io.FileWriter fw = new java.io.FileWriter(filePath);
  70. fw.write("Initial content.\n");
  71. fw.close();
  72. } catch (IOException e) {
  73. System.err.println("Error creating test file: " + e.getMessage());
  74. return;
  75. }
  79. FileContentMonitor monitor = new FileContentMonitor(filePath, checkInterval);
  80. monitor.startMonitoring();
  83. // Keep the main thread alive to allow monitoring to continue
  84. try {
  85. Thread.sleep(60000); // Run for 60 seconds
  86. } catch (InterruptedException e) {
  87. e.printStackTrace();
  88. }
  89. }
  90. }

Add your comment