AccountRepository.java

package com.example;

import java.sql.SQLException;

public interface AccountRepository {
    /**
 * Checks whether an account exists that matches the given username and password.
 *
 * @param username the account's username to look up
 * @param password the account's password to validate
 * @return `true` if an account with the provided username and password exists, `false` otherwise
 * @throws SQLException if a database access error occurs
 */
boolean findByNameAndPassword(String username, String password) throws SQLException;
    /**
 * Creates a new account record using the provided personal and credential details.
 *
 * @param firstName the account holder's given name
 * @param lastName  the account holder's family name
 * @param ssn       the account holder's social security number
 * @param password  the account password
 * @param username  the desired account username
 * @return the generated primary key for the new account when available; otherwise an implementation-specific integer status or affected-row count
 * @throws SQLException if a database access error occurs
 */
int create(String firstName, String lastName, String ssn, String password, String username) throws SQLException;
    /**
 * Update the password for the account identified by the given user ID.
 *
 * @param userId     identifier of the user whose password will be changed
 * @param newPassword the new password to set for the account
 * @return           an integer result representing the outcome of the update (for example, number of rows affected or a status code)
 * @throws SQLException if a database access error occurs while performing the update
 */
int updatePassword(long userId, String newPassword) throws SQLException;
    /**
 * Delete the account associated with the given user identifier.
 *
 * @param userId the identifier of the user to delete
 * @return an integer result code (for example, the number of rows deleted or a status code)
 * @throws SQLException if a database access error occurs
 */
int delete(long userId) throws SQLException;
}