src/main/java/com/example/Main.java (2)

3-3: Consider explicit imports instead of wildcard.

Wildcard imports (java.sql.*) reduce code clarity and can lead to ambiguity. Consider importing only the classes used: Connection, DriverManager, PreparedStatement, ResultSet, SQLException.

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31-35: Empty connection test block loses diagnostic context.

The empty try block tests connectivity, but the exception wrap loses the original message context. Consider adding a descriptive error message.

         // Test connection
         try (Connection connection = DriverManager.getConnection(jdbcUrl, dbUser, dbPass)) {
+            // Connection successful
         } catch (SQLException e) {
-            throw new RuntimeException(e);
+            throw new RuntimeException("Failed to connect to database: " + e.getMessage(), e);
         }

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Review profile: CHILL

Plan: Pro

src/main/java/com/example/Main.java (1)

102-116: Consider extracting connection creation to reduce duplication.

Each method creates its own Connection via DriverManager.getConnection(...). For a lab exercise this is fine, but for larger applications consider:

• Storing credentials in instance fields after validation in run()
• Using a helper method or connection pool

Example helper:

private Connection getConnection() throws SQLException {
    return DriverManager.getConnection(this.jdbcUrl, this.dbUser, this.dbPass);
}

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Review profile: CHILL

Plan: Pro

src/main/java/com/example/Main.java (4)

135-141: Add feedback when no mission is found for the given ID

If the query returns no rows, the user gets no output at all. Add an else branch after rs.next() to print a clear “mission not found” message so the user knows the ID didn’t match anything.

-                try (ResultSet rs = stmt.executeQuery()) {
-                    if (rs.next()) {
-                        System.out.println("Mission ID: " + rs.getLong("mission_id"));
-                        System.out.println("Spacecraft: " + rs.getString("spacecraft"));
-                        System.out.println("Launch Date: " + rs.getDate("launch_date"));
-                    }
-                }
+                try (ResultSet rs = stmt.executeQuery()) {
+                    if (rs.next()) {
+                        System.out.println("Mission ID: " + rs.getLong("mission_id"));
+                        System.out.println("Spacecraft: " + rs.getString("spacecraft"));
+                        System.out.println("Launch Date: " + rs.getDate("launch_date"));
+                    } else {
+                        System.out.println("No mission found with mission_id " + missionId);
+                    }
+                }

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183-218: Security & UX in account creation (plaintext secrets and hidden username)

Two things to consider here:

1. Security (major in real systems)

   • SSN and password are both stored as plaintext (ssn and password columns).
   • validateLogin later compares the password directly in SQL.
     For production‑style code, passwords should be hashed (bcrypt/Argon2, etc.) and SSN encrypted at rest; never log or store them in clear text. I realize this is a lab, but it’s good to at least mention this and possibly structure the code so swapping in a hasher/encrypter later is easy.

2. UX: user doesn’t see the generated username
   You compute a username from first/last name but only print “Account created successfully”. The user has no direct confirmation of what username to use at login. Consider printing the username on successful creation, e.g.:

-            int rowsAffected = stmt.executeUpdate();
-            if (rowsAffected > 0) {
-                System.out.println("Account created successfully");
-            }
+            int rowsAffected = stmt.executeUpdate();
+            if (rowsAffected > 0) {
+                System.out.println("Account created successfully");
+                System.out.println("Your username is: " + username);
+            }

Also optional but helpful: validate that first/last name are non‑empty before generating the username to avoid empty or odd usernames.

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240-244: Provide feedback when no account is updated (user_id not found)

If rowsAffected is 0, the user gets no message and can’t tell whether the user_id existed. Add an else branch to inform them that no account was found for the given ID.

-                int rowsAffected = stmt.executeUpdate();
-                if (rowsAffected > 0) {
-                    System.out.println("Password updated successfully");
-                }
+                int rowsAffected = stmt.executeUpdate();
+                if (rowsAffected > 0) {
+                    System.out.println("Password updated successfully");
+                } else {
+                    System.out.println("No account found with user_id " + userId);
+                }

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268-271: Provide feedback when no account is deleted (user_id not found)

Same pattern as password update: when rowsAffected is 0 the user gets no confirmation that nothing was deleted. Add an else to indicate that the account was not found.

-                int rowsAffected = stmt.executeUpdate();
-                if (rowsAffected > 0) {
-                    System.out.println("Account deleted successfully");
-                }
+                int rowsAffected = stmt.executeUpdate();
+                if (rowsAffected > 0) {
+                    System.out.println("Account deleted successfully");
+                } else {
+                    System.out.println("No account found with user_id " + userId);
+                }

src/main/java/com/example/Main.java (2)

9-14: Consider making main public for JVM entry point compatibility

If you intend to run this class directly with java com.example.Main, the main method must be declared public static void main(String[] args). Right now it’s package‑private, which the JVM won’t recognize as an entry point. If main is only called by some other framework/launcher, this can be left as is, but it’s worth double‑checking your run configuration.

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39-52: Login failure UX: message suggests a choice but input is ignored

On invalid login, the code prints "0) Exit" then calls scanner.nextLine() and immediately returns, discarding the user input. This is misleading because typing any value produces the same result.

Either implement the suggested choice (e.g., loop to retry login vs exit) or change the message to "Press Enter to exit" to match the actual behavior.

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Review profile: CHILL

Plan: Pro