code-smell: replaced setter injection with constructor injection for better immutability

AdityaByte · AdityaByte · commit 82737d07f9bc · 2025-06-26T12:12:40.000+05:30
diff --git a/src/main/java/com/connect/config/WebSocketConfig.java b/src/main/java/com/connect/config/WebSocketConfig.java
@@ -2,6 +2,7 @@
 
 import com.connect.service.JwtTokenService;
 import com.connect.security.StompPrincipal;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
@@ -23,13 +24,13 @@
 @Configuration
 @EnableWebSocketMessageBroker
 @Slf4j
+@RequiredArgsConstructor
 public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
 
     @Value("${frontend.origin}")
     private String FRONTEND_URL;
 
-    @Autowired
-    private JwtTokenService service;
+    private final JwtTokenService service;
 
     @Override
     public void configureMessageBroker(MessageBrokerRegistry config) {
diff --git a/src/main/java/com/connect/controller/AuthController.java b/src/main/java/com/connect/controller/AuthController.java
@@ -4,8 +4,8 @@
 
 import com.connect.dto.LoginUserDTO;
 import com.connect.dto.OtpDTO;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -21,10 +21,10 @@
 @RestController
 @RequestMapping("/auth")
 @Slf4j
+@RequiredArgsConstructor
 public class AuthController {
 
-    @Autowired
-    private AuthService authService;
+    private final AuthService authService;
 
     // Handler method for handling the signup functionality.
     @PostMapping("/signup")
diff --git a/src/main/java/com/connect/controller/ChatRoomController.java b/src/main/java/com/connect/controller/ChatRoomController.java
@@ -7,11 +7,9 @@
 import com.connect.service.ChatUserService;
 import com.connect.service.JwtTokenService;
 import com.connect.service.RoomService;
-import com.connect.utils.JwtUtil;
 import jakarta.servlet.http.HttpServletRequest;
-import lombok.AllArgsConstructor;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.messaging.handler.annotation.MessageMapping;
@@ -26,16 +24,13 @@
 
 @RestController
 @Slf4j
-@AllArgsConstructor
+@RequiredArgsConstructor
 public class ChatRoomController {
 
-    private ChatUserService chatUserService;
-
-    private RoomService roomService;
-
-    private JwtTokenService jwtTokenService;
-
-    private SimpMessagingTemplate messagingTemplate;
+    private final ChatUserService chatUserService;
+    private final RoomService roomService;
+    private final JwtTokenService jwtTokenService;
+    private final SimpMessagingTemplate messagingTemplate;
 
     // Route for handling the joining message.
     @MessageMapping("/chat.join")
diff --git a/src/main/java/com/connect/controller/ChatUserController.java b/src/main/java/com/connect/controller/ChatUserController.java
@@ -2,9 +2,8 @@
 
 import com.connect.dto.MessageDTO;
 import com.connect.dto.UserDTO;
-import com.connect.model.Message;
-import com.connect.model.User;
 import com.connect.service.ChatUserService;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.messaging.handler.annotation.MessageMapping;
@@ -14,7 +13,6 @@
 import org.springframework.web.bind.annotation.RestController;
 
 import java.util.List;
-import java.util.Optional;
 import java.util.stream.Collectors;
 
 // ChatUserController
@@ -23,13 +21,11 @@
 
 @RestController
 @Slf4j
+@RequiredArgsConstructor
 public class ChatUserController {
 
-    @Autowired
-    private ChatUserService chatUserService;
-
-    @Autowired
-    private SimpMessagingTemplate messagingTemplate;
+    private final ChatUserService chatUserService;
+    private final SimpMessagingTemplate messagingTemplate;
 
     @MessageMapping("/greet")
     public void handleGreeting(SimpMessageHeaderAccessor headerAccessor) {
diff --git a/src/main/java/com/connect/controller/TokenController.java b/src/main/java/com/connect/controller/TokenController.java
@@ -1,25 +1,23 @@
 package com.connect.controller;
 
 import com.connect.service.JwtTokenService;
-import com.connect.utils.JwtUtil;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
-import java.util.Map;
 import java.util.Optional;
 
 // Controller for handling the Verify Token Request
 
 @RestController
 @RequestMapping("/api")
 @Slf4j
+@RequiredArgsConstructor
 public class TokenController {
 
-    @Autowired
-    private JwtTokenService tokenService;
+    private final JwtTokenService tokenService;
 
     @GetMapping("/verify-token")
     public ResponseEntity<?> verifyToken(@RequestHeader("Authorization") String authHeader) {
diff --git a/src/main/java/com/connect/dto/RoomDTO.java b/src/main/java/com/connect/dto/RoomDTO.java
@@ -6,8 +6,6 @@
 import lombok.NoArgsConstructor;
 import lombok.Setter;
 
-import java.time.LocalDateTime;
-
 @Getter
 @Setter
 @NoArgsConstructor
diff --git a/src/main/java/com/connect/kafka/KafkaListenerService.java b/src/main/java/com/connect/kafka/KafkaListenerService.java
@@ -2,17 +2,17 @@
 
 import com.connect.buffer.MessageBuffer;
 import com.connect.model.Message;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.kafka.annotation.KafkaListener;
 import org.springframework.stereotype.Service;
 
 @Service
 @Slf4j
+@RequiredArgsConstructor
 public class KafkaListenerService {
 
-    @Autowired
-    private MessageBuffer messageBuffer;
+    private final MessageBuffer messageBuffer;
 
     @KafkaListener(topics = "chat", groupId = "chat-group")
     public void consumeEvent(Message message) {
diff --git a/src/main/java/com/connect/kafka/KafkaPublisherService.java b/src/main/java/com/connect/kafka/KafkaPublisherService.java
@@ -1,8 +1,8 @@
 package com.connect.kafka;
 
 import com.connect.model.Message;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.kafka.core.KafkaTemplate;
 import org.springframework.kafka.support.SendResult;
 import org.springframework.stereotype.Service;
@@ -11,10 +11,10 @@
 
 @Service
 @Slf4j
+@RequiredArgsConstructor
 public class KafkaPublisherService {
 
-    @Autowired
-    private KafkaTemplate<String, Object> kafkaTemplate;
+    private final KafkaTemplate<String, Object> kafkaTemplate;
 
     public void sendEvent(Message message) {
         log.info("Message received: {}", message.toString());
diff --git a/src/main/java/com/connect/model/Message.java b/src/main/java/com/connect/model/Message.java
@@ -15,9 +15,9 @@
 @ToString
 @Document(collection = "messages")
 public class Message {
+
     @Id
     private ObjectId id;
-
     private String roomId;
     private String sender;
     private String message;
diff --git a/src/main/java/com/connect/repository/RoomRepository.java b/src/main/java/com/connect/repository/RoomRepository.java
@@ -2,8 +2,8 @@
 
 import com.connect.model.Message;
 import com.connect.model.Room;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.mongodb.core.MongoTemplate;
 import org.springframework.data.mongodb.core.query.Criteria;
 import org.springframework.data.mongodb.core.query.Query;
@@ -14,10 +14,10 @@
 
 @Repository
 @Slf4j
+@RequiredArgsConstructor
 public class RoomRepository {
 
-    @Autowired
-    private MongoTemplate mongoTemplate;
+    private final MongoTemplate mongoTemplate;
 
     public Optional<Room> addRoom(Room room) {
         return Optional.of(mongoTemplate.insert(room));
diff --git a/src/main/java/com/connect/repository/UserRepository.java b/src/main/java/com/connect/repository/UserRepository.java
@@ -5,6 +5,7 @@
 import java.util.concurrent.CompletableFuture;
 
 import com.connect.enums.UserStatus;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.mongodb.core.FindAndModifyOptions;
@@ -19,10 +20,10 @@
 
 @Repository
 @Slf4j
+@RequiredArgsConstructor
 public class UserRepository {
 
-    @Autowired
-    private MongoTemplate mongoTemplate;
+    private final MongoTemplate mongoTemplate;
 
     // Repository method for making db queries and interacting with the database.
 
diff --git a/src/main/java/com/connect/security/CustomUserDetails.java b/src/main/java/com/connect/security/CustomUserDetails.java
@@ -1,7 +1,6 @@
 package com.connect.security;
 
 import com.connect.model.User;
-import lombok.Getter;
 import org.springframework.security.core.GrantedAuthority;
 import org.springframework.security.core.userdetails.UserDetails;
 
diff --git a/src/main/java/com/connect/security/CustomUserDetailsImpl.java b/src/main/java/com/connect/security/CustomUserDetailsImpl.java
@@ -2,6 +2,7 @@
 
 import java.util.Optional;
 
+import lombok.RequiredArgsConstructor;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.security.core.userdetails.UserDetailsService;
 import org.springframework.security.core.userdetails.UsernameNotFoundException;
@@ -11,10 +12,10 @@
 import com.connect.repository.UserRepository;
 
 @Component
+@RequiredArgsConstructor
 public class CustomUserDetailsImpl implements UserDetailsService {
 
-    @Autowired
-    private UserRepository userRepository;
+    private final UserRepository userRepository;
 
     @Override
     public CustomUserDetails loadUserByUsername(String email) throws UsernameNotFoundException {
diff --git a/src/main/java/com/connect/service/AuthService.java b/src/main/java/com/connect/service/AuthService.java
@@ -9,7 +9,7 @@
 import com.connect.security.CustomUserDetails;
 import com.connect.utils.EmailUtil;
 import com.connect.utils.JwtUtil;
-import lombok.AllArgsConstructor;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.cache.annotation.CacheEvict;
 import org.springframework.security.authentication.AuthenticationManager;
@@ -29,23 +29,17 @@
 // Handles the main business logic of Authentication
 
 @Service
-@AllArgsConstructor
 @Slf4j
+@RequiredArgsConstructor
 public class AuthService {
 
-    private UserRepository repository;
-
-    private EmailService emailService;
-
-    private RedisService redisService;
-
-    private OTPService otpService;
-
-    private AuthenticationManager authenticationManager;
-
-    private JwtUtil jwtUtil;
-
-    private EmailUtil emailUtil;
+    private final UserRepository repository;
+    private final EmailService emailService;
+    private final RedisService redisService;
+    private final OTPService otpService;
+    private final AuthenticationManager authenticationManager;
+    private final JwtUtil jwtUtil;
+    private final EmailUtil emailUtil;
 
     private final PasswordEncoder passwordEncoder = new BCryptPasswordEncoder();
 
diff --git a/src/main/java/com/connect/service/ChatUserService.java b/src/main/java/com/connect/service/ChatUserService.java
@@ -5,11 +5,10 @@
 import com.connect.enums.UserStatus;
 import com.connect.kafka.KafkaPublisherService;
 import com.connect.model.Message;
-import com.connect.model.Room;
 import com.connect.model.User;
 import com.connect.repository.RoomRepository;
 import com.connect.repository.UserRepository;
-import lombok.AllArgsConstructor;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.bson.types.ObjectId;
 import org.springframework.cache.annotation.Cacheable;
@@ -22,20 +21,15 @@
 
 @Service
 @Slf4j
-@AllArgsConstructor
+@RequiredArgsConstructor
 public class ChatUserService {
 
-    private RoomService roomService;
-
-    private RoomRepository roomRepository;
-
-    private JwtTokenService jwtTokenService;
-
-    private UserRepository userRepository;
-
-    private KafkaPublisherService kafkaPublisherService;
-
-    private MessageBuffer messageBuffer;
+    private final RoomService roomService;
+    private final RoomRepository roomRepository;
+    private final JwtTokenService jwtTokenService;
+    private final UserRepository userRepository;
+    private final KafkaPublisherService kafkaPublisherService;
+    private final MessageBuffer messageBuffer;
 
     private Map<String, User> users = new ConcurrentHashMap<>();
 
diff --git a/src/main/java/com/connect/service/EmailService.java b/src/main/java/com/connect/service/EmailService.java
@@ -1,17 +1,17 @@
 package com.connect.service;
 
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.mail.SimpleMailMessage;
 import org.springframework.mail.javamail.JavaMailSender;
 import org.springframework.stereotype.Service;
 
 @Service
 @Slf4j
+@RequiredArgsConstructor
 public class EmailService {
 
-    @Autowired
-    private JavaMailSender javaMailSender;
+    private final JavaMailSender javaMailSender;
 
     public void sendEmail(String to, String subject, String text) {
         try {
diff --git a/src/main/java/com/connect/service/JwtTokenService.java b/src/main/java/com/connect/service/JwtTokenService.java
diff --git a/src/main/java/com/connect/service/OTPService.java b/src/main/java/com/connect/service/OTPService.java
diff --git a/src/main/java/com/connect/service/RedisService.java b/src/main/java/com/connect/service/RedisService.java
diff --git a/src/main/java/com/connect/service/RoomService.java b/src/main/java/com/connect/service/RoomService.java
