GodaDev

0// Authentication example for React
1AuthService.login(username, password)
2 .then(user => {
3 // Authentication successful
4 })
5 .catch(error => {
6 // Authentication failed
7 });

 0// Authentication example for .NET
 1
 2// Define a user model
 3public class User {
 4    public string Username { get; set; }
 5    public string Password { get; set; }
 6}
 7
 8// Define a service to handle authentication
 9public class AuthService {
10    private readonly UserManager<ApplicationUser> _userManager;
11    private readonly SignInManager<ApplicationUser> _signInManager;
12    private readonly IConfiguration _configuration;
13
14    public AuthService(UserManager<ApplicationUser> userManager, SignInManager<ApplicationUser> signInManager, IConfiguration configuration) {
15        _userManager = userManager;
16        _signInManager = signInManager;
17        _configuration = configuration;
18    }
19
20    public async Task<IActionResult> AuthenticateUser(User user) {
21        var result = await _signInManager.PasswordSignInAsync(user.Username, user.Password, false, lockoutOnFailure: false);
22        if (result.Succeeded) {
23            // Authentication successful
24            // Generate JWT token
25            var token = GenerateJwtToken(user);
26            return new ObjectResult(new { Token = token });
27        }
28        else {
29            // Authentication failed
30            return Unauthorized();
31        }
32    }
33
34    private string GenerateJwtToken(User user) {
35        var claims = new[] {
36            new Claim(ClaimTypes.Name, user.Username)
37            // Add more claims as needed
38        };
39
40        var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_configuration["Jwt:Key"]));
41        var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);
42
43        var token = new JwtSecurityToken(_configuration["Jwt:Issuer"],
44                                          _configuration["Jwt:Issuer"],
45                                          claims,
46                                          expires: DateTime.Now.AddMinutes(30),
47                                          signingCredentials: creds);
48
49        return new JwtSecurityTokenHandler().WriteToken(token);
50    }
51}
52
53// Define a controller to handle authentication requests
54[ApiController]
55[Route("api/[controller]")]
56public class AuthController : ControllerBase {
57    private readonly AuthService _authService;
58
59    public AuthController(AuthService authService) {
60        _authService = authService;
61    }
62
63    [HttpPost("login")]
64    public async Task<IActionResult> AuthenticateUser(User user) {
65        return await _authService.AuthenticateUser(user);
66    }
67}

 0// Authentication example for Spring Boot
 1
 2// Define a user model
 3public class User {
 4    private String username;
 5    private String password;
 6
 7    // Getters and setters
 8}
 9
10// Define a service to handle authentication
11@Service
12public class AuthService {
13    @Autowired
14    private AuthenticationManager authenticationManager;
15
16    @Autowired
17    private JwtTokenUtil jwtTokenUtil;
18
19    public ResponseEntity<?> authenticateUser(User user) {
20        // Authenticate the user
21        final Authentication authentication = authenticationManager.authenticate(
22                new UsernamePasswordAuthenticationToken(user.getUsername(), user.getPassword()));
23
24        SecurityContextHolder.getContext().setAuthentication(authentication);
25
26        // Generate JWT token
27        final String token = jwtTokenUtil.generateToken(authentication);
28
29        // Return the token
30        return ResponseEntity.ok(new JwtResponse(token));
31    }
32}
33
34// Define a controller to handle authentication requests
35@RestController
36@RequestMapping("/api/auth")
37public class AuthController {
38    @Autowired
39    private AuthService authService;
40
41    @PostMapping("/login")
42    public ResponseEntity<?> authenticateUser(@Valid @RequestBody User user) {
43        return authService.authenticateUser(user);
44    }
45}

 0// Authentication example for Node.js
 1
 2const express = require('express');
 3const bodyParser = require('body-parser');
 4const passport = require('passport');
 5const LocalStrategy = require('passport-local').Strategy;
 6const bcrypt = require('bcryptjs');
 7const jwt = require('jsonwebtoken');
 8
 9const app = express();
10const PORT = process.env.PORT || 3000;
11
12// Middleware
13app.use(bodyParser.urlencoded({ extended: false }));
14app.use(bodyParser.json());
15
16// Sample user data (replace with your database integration)
17const users = [
18  {
19    id: 1,
20    username: 'user1',
21    password: '$2a$10$P7S8/gCrr46q7I9GfhwuT.6jXg2D9ndd2Pmv3lRYqoq/OZvwSZbJG' // Hashed password: 'password'
22  }
23];
24
25// Passport setup
26passport.use(new LocalStrategy({ usernameField: 'username', passwordField: 'password' },
27  function(username, password, done) {
28    const user = users.find(u => u.username === username);
29    if (!user) {
30      return done(null, false, { message: 'Incorrect username.' });
31    }
32    bcrypt.compare(password, user.password, function(err, res) {
33      if (res) {
34        return done(null, user);
35      } else {
36        return done(null, false, { message: 'Incorrect password.' });
37      }
38    });
39  }
40));
41
42// Login route
43app.post('/login', passport.authenticate('local', { session: false }), function(req, res) {
44  const token = jwt.sign({ id: req.user.id, username: req.user.username }, 'your_secret_key');
45  res.json({ token });
46});
47
48// Start server
49app.listen(PORT, () => {
50  console.log(`Server is running on port ${PORT}`);
51});

 0// Authentication example for iOS
 1
 2import UIKit
 3import FirebaseAuth
 4
 5class LoginViewController: UIViewController {
 6    @IBOutlet weak var emailTextField: UITextField!
 7    @IBOutlet weak var passwordTextField: UITextField!
 8
 9    override func viewDidLoad() {
10        super.viewDidLoad()
11    }
12
13    @IBAction func loginButtonTapped(_ sender: UIButton) {
14        guard let email = emailTextField.text, !email.isEmpty,
15              let password = passwordTextField.text, !password.isEmpty else {
16            return
17        }
18
19        Auth.auth().signIn(withEmail: email, password: password) { [weak self] authResult, error in
20            guard let strongSelf = self else { return }
21            if let error = error {
22                // Authentication failed
23                print("Failed to sign in: \(error.localizedDescription)")
24                // Handle error appropriately (e.g., show alert)
25                return
26            }
27
28            // Authentication successful
29            print("User signed in")
30            // Proceed to next screen or perform necessary actions
31        }
32    }
33}

 0// Authentication example for Android using Firebase Authentication
 1
 2// Define a LoginActivity to handle user login
 3public class LoginActivity extends AppCompatActivity {
 4    private FirebaseAuth mAuth;
 5
 6    @Override
 7    protected void onCreate(Bundle savedInstanceState) {
 8        super.onCreate(savedInstanceState);
 9        setContentView(R.layout.activity_login);
10
11        mAuth = FirebaseAuth.getInstance();
12
13        // Example login button click listener
14        findViewById(R.id.loginButton).setOnClickListener(new View.OnClickListener() {
15            @Override
16            public void onClick(View v) {
17                String email = ((EditText) findViewById(R.id.emailEditText)).getText().toString();
18                String password = ((EditText) findViewById(R.id.passwordEditText)).getText().toString();
19
20                // Call method to perform login
21                loginUser(email, password);
22            }
23        });
24    }
25
26    private void loginUser(String email, String password) {
27        mAuth.signInWithEmailAndPassword(email, password)
28            .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
29                @Override
30                public void onComplete(@NonNull Task<AuthResult> task) {
31                    if (task.isSuccessful()) {
32                        // Authentication successful
33                        FirebaseUser user = mAuth.getCurrentUser();
34                        // Proceed to next activity or perform necessary actions
35                    } else {
36                        // Authentication failed
37                        Toast.makeText(LoginActivity.this, "Authentication failed.", Toast.LENGTH_SHORT).show();
38                    }
39                }
40            });
41    }
42}

 0// Authentication example for Flutter using Firebase Authentication
 1
 2// Define a StatefulWidget for login page
 3class LoginPage extends StatefulWidget {
 4  @override
 5  _LoginPageState createState() => _LoginPageState();
 6}
 7
 8class _LoginPageState extends State<LoginPage> {
 9  final FirebaseAuth _auth = FirebaseAuth.instance;
10  final TextEditingController _emailController = TextEditingController();
11  final TextEditingController _passwordController = TextEditingController();
12
13  @override
14  Widget build(BuildContext context) {
15    return Scaffold(
16      appBar: AppBar(title: Text('Login')),
17      body: Padding(
18        padding: EdgeInsets.all(16.0),
19        child: Column(
20          crossAxisAlignment: CrossAxisAlignment.center,
21          children: <Widget>[
22            TextField(
23              controller: _emailController,
24              decoration: InputDecoration(labelText: 'Email'),
25            ),
26            TextField(
27              controller: _passwordController,
28              decoration: InputDecoration(labelText: 'Password'),
29              obscureText: true,
30            ),
31            RaisedButton(
32              onPressed: () async {
33                String email = _emailController.text;
34                String password = _passwordController.text;
35                try {
36                  UserCredential userCredential = await _auth.signInWithEmailAndPassword(
37                      email: email,
38                      password: password,
39                  );
40                  // Authentication successful, proceed to next screen
41                } catch (e) {
42                  // Authentication failed
43                  print('Failed to login: $e');
44                }
45              },
46              child: Text('Login'),
47            ),
48          ],
49        ),
50      ),
51    );
52  }
53}