Implemented JWT Generate Token.

src/main/java/com/neuroncrafters/auth_app/config/SecurityConfig.java

@@ -1,11 +1,14 @@
 package com.neuroncrafters.auth_app.config;
 
+import com.neuroncrafters.auth_app.dtos.ApiError;
 import com.neuroncrafters.auth_app.security.JwtAuthenticationFilter;
 import lombok.RequiredArgsConstructor;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.http.HttpStatus;
+import org.springframework.security.authentication.AuthenticationManager;
 import org.springframework.security.config.Customizer;
+import org.springframework.security.config.annotation.authentication.configuration.AuthenticationConfiguration;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer;
 import org.springframework.security.config.http.SessionCreationPolicy;
@@ -44,13 +47,13 @@ public SecurityFilterChain defaultSecurityFilterChain(HttpSecurity http) throws
                 .cors(Customizer.withDefaults())
                 .sessionManagement(sm ->
                         sm.sessionCreationPolicy(SessionCreationPolicy.STATELESS))
-                .authorizeHttpRequests(authorizeRequests ->
+                .authorizeHttpRequests(authorizeHttpRequests ->
                 // Skip authorization for register and login
-                authorizeRequests
-                        .requestMatchers("/api/v1/auth/register").permitAll()
-                        .requestMatchers("/api/v1/auth/login").permitAll()
+                authorizeHttpRequests
+                        .requestMatchers("/api/v1/auth/**").permitAll()
                         .anyRequest().authenticated()
-        ).exceptionHandling(ex ->
+        )
+                .exceptionHandling(ex ->
                         ex.authenticationEntryPoint(
                                 (request,
                                  response,
@@ -59,12 +62,14 @@ public SecurityFilterChain defaultSecurityFilterChain(HttpSecurity http) throws
                                     authException.printStackTrace();
                                     response.setStatus(HttpStatus.UNAUTHORIZED.value());
                                     response.setContentType("application/json");
-                                    String message = "Unauthorized Access! " + authException.getMessage();
-                                    Map<String, String> errorMap = Map.of("message", message,
-                                            "statusCode", String.valueOf(401),
-                                            "error", "Unauthorized");
+                                    String error = (String) request.getAttribute("error");
+                                    String message = authException.getMessage();
+                                    if (error != null) {
+                                        message = error;
+                                    }
+                                    ApiError apiError = ApiError.of(HttpStatus.UNAUTHORIZED.value(), "Unauthorized Access !!", message, request.getRequestURI());
                                     var objectMapper = new ObjectMapper();
-                                    response.getWriter().write(objectMapper.writeValueAsString(errorMap));
+                                    response.getWriter().write(objectMapper.writeValueAsString(apiError));
                                 }))
                 .addFilterBefore(jwtAuthenticationFilter, UsernamePasswordAuthenticationFilter.class);
         return http.build();
@@ -76,4 +81,9 @@ public PasswordEncoder passwordEncoder() {
     }
 
 
+    @Bean
+    public AuthenticationManager authenticationManager(AuthenticationConfiguration configuration){
+        return configuration.getAuthenticationManager();
+    }
+
 }

src/main/java/com/neuroncrafters/auth_app/controllers/AuthController.java

@@ -1,10 +1,22 @@
 package com.neuroncrafters.auth_app.controllers;
 
+import com.neuroncrafters.auth_app.dtos.LoginRequest;
+import com.neuroncrafters.auth_app.dtos.TokenResponse;
 import com.neuroncrafters.auth_app.dtos.UserDto;
+import com.neuroncrafters.auth_app.entities.User;
+import com.neuroncrafters.auth_app.repositories.UserRepository;
+import com.neuroncrafters.auth_app.security.JwtService;
 import com.neuroncrafters.auth_app.services.AuthService;
+import com.neuroncrafters.auth_app.services.UserService;
 import lombok.AllArgsConstructor;
+import org.modelmapper.ModelMapper;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.security.authentication.AuthenticationManager;
+import org.springframework.security.authentication.BadCredentialsException;
+import org.springframework.security.authentication.DisabledException;
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
+import org.springframework.security.core.Authentication;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -16,6 +28,33 @@
 public class AuthController {
 
     private final AuthService authService;
+    private final AuthenticationManager authenticationManager;
+    private final UserRepository userRepository;
+    private final JwtService jwtService;
+    private final ModelMapper modelMapper;
+
+    @PostMapping("/login")
+    public ResponseEntity<TokenResponse> login(@RequestBody LoginRequest loginRequest) {
+        // 1. authenticate
+        Authentication authentication = authenticate(loginRequest);
+        User user = userRepository.findByEmail(loginRequest.email()).orElseThrow(() -> new BadCredentialsException("User not found!"));
+        if(!user.isEnable()) {
+            throw new DisabledException("User is disabled");
+        }
+
+        // 2. Generate JWT token
+        String accessToken = jwtService.generateToken(user);
+        TokenResponse response = TokenResponse.of(accessToken, "", jwtService.getAccessTtlSeconds(), modelMapper.map(user, UserDto.class));
+        return ResponseEntity.ok(response);
+    }
+
+    private Authentication authenticate(LoginRequest loginRequest) {
+        try {
+            return authenticationManager.authenticate(new UsernamePasswordAuthenticationToken(loginRequest.email(), loginRequest.password()));
+        } catch (Exception e) {
+            throw new BadCredentialsException("Invalid email or password");
+        }
+    }
 
     @PostMapping("/register")
     public ResponseEntity<UserDto> registerUser(@RequestBody UserDto user) {

src/main/java/com/neuroncrafters/auth_app/dtos/ApiError.java

@@ -0,0 +1,20 @@
+package com.neuroncrafters.auth_app.dtos;
+
+import org.springframework.http.HttpStatus;
+
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+
+public record ApiError(
+        int status,
+        String error,
+        String message,
+        String path,
+        OffsetDateTime timestamp
+) {
+
+    public static ApiError of(int status, String error, String message, String path) {
+        return new ApiError(status, error, message, path, OffsetDateTime.now(ZoneOffset.UTC));
+    }
+
+}

src/main/java/com/neuroncrafters/auth_app/dtos/LoginRequest.java

@@ -0,0 +1,7 @@
+package com.neuroncrafters.auth_app.dtos;
+
+public record LoginRequest(
+        String email,
+        String password
+) {
+}

src/main/java/com/neuroncrafters/auth_app/dtos/TokenResponse.java

@@ -0,0 +1,13 @@
+package com.neuroncrafters.auth_app.dtos;
+
+public record TokenResponse(
+    String accessToken,
+    String refreshToken,
+    long expiresIn,
+    String tokenType,
+    UserDto user
+){
+    public static TokenResponse of(String accessToken, String refreshToken, long expiresIn, UserDto user) {
+        return new TokenResponse(accessToken, refreshToken, expiresIn, "Bearer", user);
+    }
+}

src/main/java/com/neuroncrafters/auth_app/exceptions/GlobalExceptionHandler.java

@@ -1,14 +1,34 @@
 package com.neuroncrafters.auth_app.exceptions;
 
+import com.neuroncrafters.auth_app.dtos.ApiError;
 import com.neuroncrafters.auth_app.dtos.ErrorResponse;
+import io.jsonwebtoken.ExpiredJwtException;
+import io.jsonwebtoken.JwtException;
+import jakarta.servlet.http.HttpServletRequest;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.security.authentication.BadCredentialsException;
+import org.springframework.security.authentication.CredentialsExpiredException;
+import org.springframework.security.authentication.DisabledException;
+import org.springframework.security.core.AuthenticationException;
+import org.springframework.security.core.userdetails.UsernameNotFoundException;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.RestControllerAdvice;
 
 @RestControllerAdvice
 public class GlobalExceptionHandler {
 
+    @ExceptionHandler({
+            UsernameNotFoundException.class,
+            BadCredentialsException.class,
+            CredentialsExpiredException.class,
+            DisabledException.class
+    })
+    public ResponseEntity<ApiError> handleAuthException(Exception e, HttpServletRequest request) {
+        var apiError = ApiError.of(HttpStatus.BAD_REQUEST.value(), "Bad Request", e.getMessage(), request.getRequestURI());
+        return ResponseEntity.badRequest().body(apiError);
+    }
+
     // resource not found exception handler :: method
     @ExceptionHandler(ResourceNotFoundException.class)
     public ResponseEntity<ErrorResponse> handleResourceNotFoundException(ResourceNotFoundException ex){

src/main/java/com/neuroncrafters/auth_app/security/CustomUserDetailService.java

@@ -3,6 +3,7 @@
 import com.neuroncrafters.auth_app.repositories.UserRepository;
 import lombok.AllArgsConstructor;
 import lombok.RequiredArgsConstructor;
+import org.springframework.security.authentication.BadCredentialsException;
 import org.springframework.security.core.userdetails.UserDetails;
 import org.springframework.security.core.userdetails.UserDetailsService;
 import org.springframework.security.core.userdetails.UsernameNotFoundException;
@@ -16,6 +17,6 @@ public class CustomUserDetailService implements UserDetailsService {
 
     @Override
     public UserDetails loadUserByUsername(String email) throws UsernameNotFoundException {
-        return userRepository.findByEmail(email).orElseThrow(() -> new UsernameNotFoundException(email));
+        return userRepository.findByEmail(email).orElseThrow(() -> new BadCredentialsException(email));
     }
 }

src/main/java/com/neuroncrafters/auth_app/security/JwtAuthenticationFilter.java

@@ -89,16 +89,16 @@ protected void doFilterInternal(HttpServletRequest request, HttpServletResponse
                     }
                 });
             } catch (ExpiredJwtException e) {
-                e.printStackTrace();
-            } catch (MalformedJwtException e) {
-                e.printStackTrace();
-            } catch (JwtException e) {
-                e.printStackTrace();
+                request.setAttribute("error", "Token is expired");
             } catch (Exception e) {
-                e.printStackTrace();
+                request.setAttribute("error", "Token is invalid");
             }
-
         }
         filterChain.doFilter(request, response);
     }
+
+    @Override
+    protected boolean shouldNotFilter(HttpServletRequest request) {
+        return request.getRequestURI().startsWith("/api/v1/auth/");
+    }
 }

src/main/java/com/neuroncrafters/auth_app/security/JwtService.java

@@ -7,6 +7,8 @@
 import io.jsonwebtoken.Jwts;
 import io.jsonwebtoken.SignatureAlgorithm;
 import io.jsonwebtoken.security.Keys;
+import lombok.Getter;
+import lombok.Setter;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 
@@ -21,6 +23,8 @@
 import java.util.UUID;
 
 @Service
+@Getter
+@Setter
 public class JwtService {
     private final SecretKey key;
     private final long accessTtlSeconds;

src/main/resources/application-dev.yaml

@@ -35,7 +35,7 @@ logging:
 
 security:
   jwt:
-    secret: ${JWT_SECRET:2Ajw}a#.Eyd/8IBos6y@4Ixvyvp75zz/Oyep?n[p}h}
+    secret: ${JWT_SECRET:258b67b9da8be40b7af5960068fdf0e4faa81738bf56615e146574f9e117cc73a86ce0803718b114c2a811a24065484345855013354b31723a4f947f27baf1aa}
     issuer: ${JWT_ISSUER:api.substring.com}
     access-ttl-seconds: ${JWT_ACCESS_TTL_SECONDS:3600}
     refresh-ttl-seconds: ${JWT_REFRESH_TTL_SECONDS:86400}