1. import java.util.HashMap;
  2. import java.util.Map;
  4. public class UserDataService {
  6. private static final String DATABASE_URL = "non_production_db_url"; // Replace with actual non-production URL
  7. private static final String DATABASE_USER = "non_production_user"; // Replace with actual non-production user
  8. private static final String DATABASE_PASSWORD = "non_production_password"; // Replace with actual non-production password
  10. private static Map<String, UserData> userDataCache = new HashMap<>();
  12. public UserData getUserData(String userId) {
  13. try {
  14. // Attempt to retrieve data from the cache
  15. UserData userData = userDataCache.get(userId);
  16. if (userData != null) {
  17. return userData;
  18. }
  20. // If not in cache, fetch from the database
  21. userData = fetchUserDataFromDatabase(userId);
  23. // If successfully fetched, add to the cache
  24. if (userData != null) {
  25. userDataCache.put(userId, userData);
  26. }
  27. return userData;
  29. } catch (Exception e) {
  30. // Log the error (replace with your logging framework)
  31. System.err.println("Error fetching user data for user ID: " + userId + ". Error: " + e.getMessage());
  32. // Handle the error gracefully (e.g., return null, throw a custom exception, etc.)
  33. return null; //Return null on failure
  34. }
  35. }
  37. private UserData fetchUserDataFromDatabase(String userId) {
  38. // Simulate database interaction with graceful failure handling
  39. try {
  40. // Replace with your actual database connection logic
  41. // This is a placeholder for database interaction.
  42. // In a real application, use JDBC or a similar database access library.
  44. // Simulate a database query
  45. if (userId.equals("invalid_user")) {
  46. throw new Exception("Simulated database error for invalid user");
  47. }
  49. // Create a UserData object
  50. UserData userData = new UserData(userId, "John Doe", "john.doe@example.com");
  52. return userData;
  54. } catch (Exception e) {
  55. // Log the error (replace with your logging framework)
  56. System.err.println("Error fetching user data from database for user ID: " + userId + ". Error: " + e.getMessage());
  57. // Handle the error gracefully
  58. return null; // Return null on failure
  59. }
  60. }
  62. // Simple UserData class for demonstration
  63. public static class UserData {
  64. private final String userId;
  65. private final String name;
  66. private final String email;
  68. public UserData(String userId, String name, String email) {
  69. this.userId = userId;
  70. this.name = name;
  71. this.email = email;
  72. }
  74. public String getUserId() {
  75. return userId;
  76. }
  78. public String getName() {
  79. return name;
  80. }
  82. public String getEmail() {
  83. return email;
  84. }
  86. @Override
  87. public String toString() {
  88. return "UserData{" +
  89. "userId='" + userId + '\'' +
  90. ", name='" + name + '\'' +
  91. ", email='" + email + '\'' +
  92. '}';
  93. }
  94. }
  98. public static void main(String[] args) {
  99. UserDataService service = new UserDataService();
  101. UserData user1 = service.getUserData("user123");
  102. if (user1 != null) {
  103. System.out.println("User 1: " + user1);
  104. } else {
  105. System.out.println("User 1 not found.");
  106. }
  108. UserData user2 = service.getUserData("invalid_user");
  109. if (user2 != null) {
  110. System.out.println("User 2: " + user2);
  111. } else {
  112. System.out.println("User 2 not found.");
  113. }
  114. }
  115. }

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