feat : get attachment list by socket

src/main/java/org/bssm/attachit/domain/attachment/exception/SocketIOException.java

@@ -0,0 +1,11 @@
+package org.bssm.attachit.domain.attachment.exception;
+
+import org.bssm.attachit.global.error.exception.AttachItException;
+import org.bssm.attachit.global.error.exception.ErrorCode;
+
+public class SocketIOException extends AttachItException {
+    public static final SocketIOException EXCEPTION = new SocketIOException(ErrorCode.SOCKET_OUTPUT);
+    public SocketIOException(ErrorCode errorCode) {
+        super(errorCode);
+    }
+}

src/main/java/org/bssm/attachit/domain/attachment/service/GetAttachmentListService.java

@@ -0,0 +1,19 @@
+package org.bssm.attachit.domain.attachment.service;
+
+import lombok.RequiredArgsConstructor;
+import org.bssm.attachit.domain.attachment.domain.Attachment;
+import org.bssm.attachit.domain.attachment.repository.AttachmentRepository;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+@RequiredArgsConstructor
+public class GetAttachmentListService {
+
+    private final AttachmentRepository attachmentRepository;
+
+    public List<Attachment> execute() {
+        return attachmentRepository.findAll();
+    }
+}

src/main/java/org/bssm/attachit/global/error/exception/ErrorCode.java

@@ -18,7 +18,9 @@ public enum ErrorCode {
     FILE_ERROR(500, "파일 오류"),
 
     UNAUTHORIZED(403, "권한이 올바르지 않습니다"),
-    BAD_REQUEST(400, "잘못된 요청입니다");
+    BAD_REQUEST(400, "잘못된 요청입니다"),
+
+    SOCKET_OUTPUT(500, "소켓 데이터 전송 에러");
 
     private final int status;
     private final String message;

src/main/java/org/bssm/attachit/global/security/SecurityConfig.java

@@ -6,6 +6,7 @@
 import org.bssm.attachit.global.jwt.util.JwtUtil;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.EnableScheduling;
 import org.springframework.security.config.Customizer;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
@@ -20,6 +21,7 @@
 @Configuration
 @EnableWebSecurity
 @RequiredArgsConstructor
+@EnableScheduling
 public class SecurityConfig {
 
     private final JwtUtil jwtUtil;

src/main/java/org/bssm/attachit/global/security/socket/WebSocketConfig.java

@@ -0,0 +1,18 @@
+package org.bssm.attachit.global.security.socket;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.socket.config.annotation.*;
+
+@Configuration
+@EnableWebSocket
+@RequiredArgsConstructor
+public class WebSocketConfig implements WebSocketConfigurer {
+
+    private final WebSocketHandler webSocketHandler;
+
+    @Override
+    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
+        registry.addHandler(webSocketHandler, "/attachments").setAllowedOrigins("*");
+    }
+}

src/main/java/org/bssm/attachit/global/security/socket/WebSocketHandler.java

@@ -0,0 +1,51 @@
+package org.bssm.attachit.global.security.socket;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.RequiredArgsConstructor;
+import org.bssm.attachit.domain.attachment.domain.Attachment;
+import org.bssm.attachit.domain.attachment.exception.SocketIOException;
+import org.bssm.attachit.domain.attachment.service.GetAttachmentListService;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Component;
+import org.springframework.web.socket.CloseStatus;
+import org.springframework.web.socket.TextMessage;
+import org.springframework.web.socket.WebSocketSession;
+import org.springframework.web.socket.handler.TextWebSocketHandler;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.concurrent.ConcurrentHashMap;
+
+@Component
+@RequiredArgsConstructor
+public class WebSocketHandler extends TextWebSocketHandler {
+
+    private final GetAttachmentListService getAttachmentListService;
+    private static final ObjectMapper objectMapper = new ObjectMapper();
+    private static final ConcurrentHashMap<String, WebSocketSession> CLIENTS = new ConcurrentHashMap<>();
+
+    @Override
+    public void afterConnectionEstablished(WebSocketSession session) throws RuntimeException {
+        CLIENTS.put(session.getId(), session);
+    }
+
+    @Override
+    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws RuntimeException {
+        CLIENTS.remove(session.getId());
+    }
+
+    @Scheduled(fixedRate = 1000, initialDelay = 5000)
+    public void sendAttachmentListToAllClients() throws JsonProcessingException {
+        List<Attachment> attachmentList = getAttachmentListService.execute();
+        String jsonAttachments = objectMapper.writeValueAsString(attachmentList);
+        TextMessage message = new TextMessage(jsonAttachments);
+        CLIENTS.forEach((key, value) -> {
+            try {
+                value.sendMessage(message);
+            } catch (IOException e) {
+                throw SocketIOException.EXCEPTION;
+            }
+        });
+    }
+}