Spring Security

 @Override
    public Authentication authenticate(Authentication authentication) throws AuthenticationException {
        String username = authentication.getName();
        String password = authentication.getCredentials().toString();
        // Perform your custom authentication logic here
        // Retrieve user details from userDetailsService and validate the credentials
        // You can throw AuthenticationException if authentication fails
        // Example: retrieving user details by username from UserDetailsService
        boolean authenticated = authenticationService.authenticate(username, password);
        if (!authenticated ) {
            throw new UsernameNotFoundException("User not found");
        }
       
        // Create a fully authenticated Authentication object
        Authentication authenticated = new UsernamePasswordAuthenticationToken(
                userDetails, password, userDetails.getAuthorities());
        return authenticated;
    }

 @Override
    public Authentication authenticate(Authentication authentication) throws AuthenticationException {
        String username = authentication.getName();
        String password = authentication.getCredentials().toString();
        // Perform your custom authentication logic here
        // Retrieve user details from userDetailsService and validate the credentials
        // You can throw AuthenticationException if authentication fails
        // Example: retrieving user details by username from UserDetailsService
        boolean authenticated = authenticationService.authenticate(username, password);
        if (!authenticated ) {
            throw new UsernameNotFoundException("User not found");
        }
       
        // Create a fully authenticated Authentication object
        Authentication authenticated = new UsernamePasswordAuthenticationToken(
                userDetails, password, userDetails.getAuthorities());
        return authenticated;
    }