Untitled

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

@RestController
public class AuthController {

    private final UserService userService;
    private final JwtTokenUtil jwtTokenUtil; // Assume JwtTokenUtil for JWT token generation

    public AuthController(UserService userService, JwtTokenUtil jwtTokenUtil) {
        this.userService = userService;
        this.jwtTokenUtil = jwtTokenUtil;
    }

    @PostMapping("/signup")
    public ResponseEntity<?> signup(@RequestBody UserDto userDto) {
        userService.signup(userDto);
        return ResponseEntity.ok().build();
    }

    @PostMapping("/login")
    public ResponseEntity<?> login(@RequestBody LoginRequest loginRequest) {
        // Authenticate user
        User user = userService.findByUsername(loginRequest.getUsername());
        if (user == null || !passwordEncoder.matches(loginRequest.getPassword(), user.getPassword())) {
            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).build();
        }

        // Generate JWT token
        String token = jwtTokenUtil.generateToken(user);

        // Return token to client
        return ResponseEntity.ok(new JwtResponse(token));
    }

    @PostMapping("/logout")
    public ResponseEntity<?> logout() {
        // Perform logout operations if necessary
        return ResponseEntity.ok().build();
    }

    @PostMapping("/reset-password")
    public ResponseEntity<?> resetPassword(@RequestParam("username") String username,
                                           @RequestParam("newPassword") String newPassword) {
        User user = userService.findByUsername(username);
        if (user == null) {
            return ResponseEntity.status(HttpStatus.NOT_FOUND).build();
        }
        userService.updatePassword(username, newPassword);
        return ResponseEntity.ok().build();
    }

    @PostMapping("/update-password")
    public ResponseEntity<?> updatePassword(@RequestParam("username") String username,
                                             @RequestParam("currentPassword") String currentPassword,
                                             @RequestParam("newPassword") String newPassword) {
        User user = userService.findByUsername(username);
        if (user == null || !passwordEncoder.matches(currentPassword, user.getPassword())) {
            return ResponseEntity.status(HttpStatus.UNAUTHORIZED).build();
        }
        userService.updatePassword(username, newPassword);
        return ResponseEntity.ok().build();
    }

    @DeleteMapping("/delete-user/{username}")
    public ResponseEntity<?> deleteUser(@PathVariable("username") String username) {
        userService.deleteUserByUsername(username);
        return ResponseEntity.ok().build();
    }

    @GetMapping("/user/{username}")
    public ResponseEntity<UserDto> getUserByUsername(@PathVariable("username") String username) {
        User user = userService.findByUsername(username);
        if (user == null) {
            return ResponseEntity.notFound().build();
        }
        UserDto userDto = new UserDto();
        userDto.setUsername(user.getUsername());
        // Add other user details to the DTO as needed
        return ResponseEntity.ok(userDto);
    }

    // Add more endpoints for user-related operations as needed
}

Let's break down the provided AuthController code in detail:

RestController Annotation:

@RestController annotation marks the class as a REST controller, allowing it to handle incoming HTTP requests and return appropriate responses.
Constructor:

The constructor initializes the AuthController with instances of UserService and JwtTokenUtil. These dependencies are injected through constructor-based dependency injection.
Signup Endpoint:

@PostMapping("/signup") annotation maps the signup() method to handle POST requests to the "/signup" endpoint.
The signup() method takes a UserDto object in the request body, signs up the user by calling userService.signup(userDto), and returns a ResponseEntity with an HTTP status of 200 (OK).
Login Endpoint:

@PostMapping("/login") annotation maps the login() method to handle POST requests to the "/login" endpoint.
The login() method takes a LoginRequest object in the request body, authenticates the user by calling userService.findByUsername() and comparing the password with the stored password using passwordEncoder.matches().
If authentication succeeds, a JWT token is generated using jwtTokenUtil.generateToken(user) and returned to the client in the response body.
If authentication fails, an HTTP status of 401 (UNAUTHORIZED) is returned.
Logout Endpoint:

@PostMapping("/logout") annotation maps the logout() method to handle POST requests to the "/logout" endpoint.
The logout() method performs any necessary logout operations and returns an HTTP status of 200 (OK).
Reset Password Endpoint:

@PostMapping("/reset-password") annotation maps the resetPassword() method to handle POST requests to the "/reset-password" endpoint.
The resetPassword() method takes the username and new password as request parameters, finds the user by username using userService.findByUsername(), and updates the password using userService.updatePassword().
If the user is not found, an HTTP status of 404 (NOT FOUND) is returned.
Update Password Endpoint:

@PostMapping("/update-password") annotation maps the updatePassword() method to handle POST requests to the "/update-password" endpoint.
The updatePassword() method takes the username, current password, and new password as request parameters.
It authenticates the user by verifying the current password using passwordEncoder.matches(), updates the password using userService.updatePassword(), and returns an HTTP status of 200 (OK) if successful.
If authentication fails, an HTTP status of 401 (UNAUTHORIZED) is returned.
Delete User Endpoint:

@DeleteMapping("/delete-user/{username}") annotation maps the deleteUser() method to handle DELETE requests to the "/delete-user/{username}" endpoint.
The deleteUser() method takes the username as a path variable, deletes the user by username using userService.deleteUserByUsername(), and returns an HTTP status of 200 (OK).
Get User by Username Endpoint:

@GetMapping("/user/{username}") annotation maps the getUserByUsername() method to handle GET requests to the "/user/{username}" endpoint.
The getUserByUsername() method takes the username as a path variable, finds the user by username using userService.findByUsername(), converts the user to a UserDto, and returns it in a ResponseEntity.
If the user is not found, an HTTP status of 404 (NOT FOUND) is returned.
This AuthController provides endpoints for user authentication, registration, password management, and user retrieval. It integrates with UserService for business logic and JwtTokenUtil for JWT token generation.





2) 

import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Optional;

@Service
public class UserService {

    private final UserRepository userRepository;
    private final PasswordEncoder passwordEncoder;

    public UserService(UserRepository userRepository, PasswordEncoder passwordEncoder) {
        this.userRepository = userRepository;
        this.passwordEncoder = passwordEncoder;
    }

    public void signup(UserDto userDto) {
        User user = new User();
        user.setUsername(userDto.getUsername());
        user.setPassword(passwordEncoder.encode(userDto.getPassword()));
        userRepository.save(user);
    }

    public User findByUsername(String username) {
        return userRepository.findByUsername(username);
    }

    public List<User> findAll() {
        return userRepository.findAll();
    }

    public void updatePassword(String username, String newPassword) {
        User user = userRepository.findByUsername(username);
        if (user != null) {
            user.setPassword(passwordEncoder.encode(newPassword));
            userRepository.save(user);
        }
    }

    public void deleteUserByUsername(String username) {
        userRepository.deleteByUsername(username);
    }

    public Optional<User> findById(Long id) {
        return userRepository.findById(id);
    }

    public void updateUser(UserDto userDto) {
        User user = userRepository.findByUsername(userDto.getUsername());
        if (user != null) {
            user.setUsername(userDto.getUsername());
            // Update other user fields as needed
            userRepository.save(user);
        }
    }

    public boolean isUsernameAvailable(String username) {
        return userRepository.findByUsername(username) == null;
    }

    public boolean isUserExists(Long id) {
        return userRepository.existsById(id);
    }

    public void deleteById(Long id) {
        userRepository.deleteById(id);
    }

    public int countUsers() {
        return userRepository.count();
    }

    // Add other methods for user-related operations as needed
}

Certainly! Let's break down the UserService code in detail:

Service Annotation:

@Service annotation marks the class as a Spring service component, indicating that it contains business logic.
Constructor:

The constructor initializes the UserService with instances of UserRepository and PasswordEncoder. These dependencies are injected through constructor-based dependency injection.
Signup Method:

signup(UserDto userDto): This method takes a UserDto object representing user details.
It creates a new User object, sets the username and password by encoding the password using the injected PasswordEncoder, and saves the user using the UserRepository.
Find User by Username Method:

findByUsername(String username): This method retrieves a user from the database by username using the UserRepository.
Find All Users Method:

findAll(): This method retrieves all users from the database using the UserRepository.
Update Password Method:

updatePassword(String username, String newPassword): This method updates the password for a user identified by their username.
It retrieves the user from the database, sets the new password by encoding it using the PasswordEncoder, and saves the user using the UserRepository.
Delete User by Username Method:

deleteUserByUsername(String username): This method deletes a user from the database by their username using the UserRepository.
Find User by ID Method:

findById(Long id): This method retrieves a user from the database by their ID using the UserRepository.
Update User Method:

updateUser(UserDto userDto): This method updates user information based on the provided UserDto.
It retrieves the user from the database, updates the username, and saves the user using the UserRepository.
Check Username Availability Method:

isUsernameAvailable(String username): This method checks if a username is available for registration by querying the database using the UserRepository.
Check User Existence by ID Method:
isUserExists(Long id): This method checks if a user exists in the database by their ID using the UserRepository.
Delete User by ID Method:
deleteById(Long id): This method deletes a user from the database by their ID using the UserRepository.
Count Users Method:
countUsers(): This method counts the total number of users in the database using the UserRepository.
These methods encapsulate various user-related operations, such as user registration, retrieval, update, and deletion. They interact with the database through the UserRepository to perform data manipulation tasks. Additionally, password encoding is handled securely using the injected PasswordEncoder.



3) 

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String username;
    private String password; // Store encrypted password

    // Getters and setters
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

Certainly! Let's explain the provided User entity class in detail:

Entity Annotation:

@Entity annotation marks the class as a JPA entity, indicating that it is mapped to a database table.
Table Mapping:

When this entity is scanned by JPA during application startup, it will create or update a table in the database based on the entity's fields and annotations.
Id Annotation:

@Id annotation marks the field id as the primary key of the entity.
GeneratedValue Annotation:

@GeneratedValue annotation configures how the primary key value is generated.
strategy = GenerationType.IDENTITY specifies that the primary key is generated by the underlying database (auto-increment in most databases).
Fields:

id: This field represents the unique identifier for the user entity. It's annotated with @Id and @GeneratedValue for primary key generation.
username: This field represents the username of the user. It stores the username associated with the user account.
password: This field represents the encrypted password of the user. It stores the password securely after encryption.
Getters and Setters:

Getters and setters are provided for each field to allow access and modification of the entity's state.
These methods enable other parts of the application to interact with and manipulate user objects.
In summary, the User class is a JPA entity representing a user in the application. It contains fields for the user's unique identifier (id), username, and encrypted password. With JPA annotations, it is mapped to a corresponding database table, allowing for seamless interaction with the database through the JPA repository.




4)

import org.springframework.data.jpa.repository.JpaRepository;

public interface UserRepository extends JpaRepository<User, Long> {
    User findByUsername(String username);
}





import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private CustomUserDetailsService userDetailsService;

    // Configure AuthenticationManager to use CustomUserDetailsService and PasswordEncoder
    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userDetailsService)
            .passwordEncoder(passwordEncoder());
    }

    // Configure HTTP security rules
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/signup").permitAll() // Allow signup endpoint without authentication
                .anyRequest().authenticated() // Require authentication for other endpoints
                .and()
            .formLogin()
                .loginPage("/login").permitAll() // Custom login page accessible to all
                .and()
            .logout()
                .logoutUrl("/logout") // Custom logout URL
                .logoutSuccessUrl("/login?logout").permitAll() // Redirect to login page after logout
                .invalidateHttpSession(true) // Invalidate session on logout
                .and()
            .csrf().disable(); // Disable CSRF protection for simplicity
    }

    // Define PasswordEncoder bean
    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }
}

Sure, let's break down the provided SecurityConfig class in detail:

@Configuration Annotation:

This annotation indicates that the class is a configuration class for the Spring application context.
@EnableWebSecurity Annotation:

This annotation enables Spring Security's web security features.
WebSecurityConfigurerAdapter Extension:

The class extends WebSecurityConfigurerAdapter, allowing customization of Spring Security's web security configuration.
CustomUserDetailsService Autowiring:

@Autowired private CustomUserDetailsService userDetailsService;
This injects an instance of CustomUserDetailsService, which is responsible for loading user-specific data during authentication.
Authentication Configuration:

The configure(AuthenticationManagerBuilder auth) method is overridden to configure authentication.
auth.userDetailsService(userDetailsService).passwordEncoder(passwordEncoder()); sets the CustomUserDetailsService as the user details service and specifies the PasswordEncoder to use for password encoding.
HTTP Security Configuration:

The configure(HttpSecurity http) method is overridden to configure HTTP security rules.
http.authorizeRequests() configures authorization rules for URLs.
.antMatchers("/signup").permitAll() allows access to the "/signup" endpoint without authentication.
.anyRequest().authenticated() requires authentication for all other endpoints.
.formLogin() configures form-based login authentication.
.loginPage("/login").permitAll() specifies the custom login page ("/login") accessible to all users.
.logout() configures logout handling.
.logoutUrl("/logout") specifies the custom logout URL ("/logout").
.logoutSuccessUrl("/login?logout").permitAll() redirects to the login page with a logout parameter after successful logout and allows access to all users.
.invalidateHttpSession(true) invalidates the HTTP session upon logout.
.csrf().disable() disables CSRF protection for simplicity. (Note: CSRF protection should be enabled in a production environment.)
PasswordEncoder Bean Definition:

@Bean public PasswordEncoder passwordEncoder() { return new BCryptPasswordEncoder(); }
This method defines a bean of type PasswordEncoder that returns a BCryptPasswordEncoder instance.
The BCryptPasswordEncoder is a widely-used password encoder for secure password hashing.
In summary, the SecurityConfig class configures authentication and authorization rules for the Spring Security-enabled application. It specifies how users are authenticated, what URLs are accessible, and how logout is handled. Additionally, it defines a PasswordEncoder bean for securely encoding passwords.