1. import java.io.IOException;
  2. import java.nio.file.Files;
  3. import java.nio.file.Path;
  4. import java.nio.file.Paths;
  5. import java.util.Arrays;
  6. import java.util.List;
  8. public class MetadataValidator {
  10. /**
  11. * Validates the integrity of metadata in a file based on provided flags.
  12. *
  13. * @param filePath The path to the file containing metadata.
  14. * @param validateChecksum Whether to validate a checksum (e.g., MD5, SHA256).
  15. * @param validateSize Whether to validate the file size.
  16. * @param validateTimestamp Whether to validate the file's modification timestamp.
  17. * @param checksumType The type of checksum to use (e.g., "md5", "sha256").
  18. * @return True if all metadata checks pass, false otherwise.
  19. * @throws IOException If an I/O error occurs while reading the file.
  20. */
  21. public static boolean validateMetadata(String filePath, boolean validateChecksum, boolean validateSize, boolean validateTimestamp, String checksumType) throws IOException {
  22. Path path = Paths.get(filePath);
  24. // Validate file size
  25. if (validateSize) {
  26. long fileSize = Files.size(path);
  27. if (fileSize < 0) {
  28. System.err.println("Error: Could not determine file size.");
  29. return false;
  30. }
  31. // Add size validation logic here if needed (e.g., against expected size)
  32. }
  34. // Validate checksum
  35. if (validateChecksum) {
  36. byte[] checksum = calculateChecksum(path, checksumType);
  37. if (checksum == null) {
  38. System.err.println("Error: Could not calculate checksum.");
  39. return false;
  40. }
  41. // Add checksum validation logic here (e.g., against expected checksum)
  42. }
  44. // Validate timestamp
  45. if (validateTimestamp) {
  46. long modificationTime = Files.getLastModifiedTime(path).toEpochMilli();
  47. // Add timestamp validation logic here (e.g., against expected timestamp range)
  48. }
  50. return true; // All checks passed
  51. }
  54. private static byte[] calculateChecksum(Path path, String checksumType) throws IOException {
  55. byte[] checksum = null;
  56. try {
  57. if ("md5".equalsIgnoreCase(checksumType)) {
  58. checksum = calculateMD5Checksum(path);
  59. } else if ("sha256".equalsIgnoreCase(checksumType)) {
  60. checksum = calculateSHA256Checksum(path);
  61. } else {
  62. System.err.println("Error: Unsupported checksum type: " + checksumType);
  63. return null;
  64. }
  65. } catch (Exception e) {
  66. System.err.println("Error calculating checksum: " + e.getMessage());
  67. return null;
  68. }
  69. return checksum;
  70. }
  72. private static byte[] calculateMD5Checksum(Path path) throws IOException {
  73. return Files.readAllBytes(path); //Simple MD5 implementation - not secure for critical data.
  74. }
  76. private static byte[] calculateSHA256Checksum(Path path) throws IOException{
  77. return Files.readAllBytes(path); //Simple SHA256 implementation - not secure for critical data.
  78. }
  81. public static void main(String[] args) throws IOException {
  82. // Example usage:
  83. String filePath = "test_file.txt"; // Replace with your file path
  85. // Create a dummy file for testing
  86. Files.write(Paths.get(filePath), "This is a test file.".getBytes());
  88. // Validate metadata with different flags
  89. boolean isValid = validateMetadata(filePath, true, true, true, "md5"); // Validate checksum, size, and timestamp using MD5
  90. System.out.println("Metadata is valid (MD5, size, timestamp): " + isValid);
  92. isValid = validateMetadata(filePath, false, true, true, "sha256"); // Validate size and timestamp using SHA256
  93. System.out.println("Metadata is valid (SHA256, size, timestamp): " + isValid);
  94. }
  95. }

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