Added Post system. Notification system

src/main/java/site/easystartup/web/notification/controller/NotificationController.java

@@ -0,0 +1,28 @@
+package site.easystartup.web.notification.controller;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.messaging.handler.annotation.Payload;
+import org.springframework.messaging.simp.SimpMessagingTemplate;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import site.easystartup.web.notification.domian.Notification;
+
+import java.security.Principal;
+import java.util.logging.Logger;
+
+@Controller
+@RequiredArgsConstructor(onConstructor_ = @Autowired)
+public class NotificationController {
+    private final SimpMessagingTemplate messagingTemplate;
+    Logger logger = Logger.getGlobal();
+
+    @GetMapping("/notify")
+    public void notification(Principal principal, @Payload Notification notification) {
+        logger.info("Web socket sent notification to " + principal.getName());
+        messagingTemplate.convertAndSendToUser(principal.getName(), "queue/notification", notification);
+    }
+
+
+}

src/main/java/site/easystartup/web/notification/controller/NotificationRestController.java

@@ -0,0 +1,32 @@
+package site.easystartup.web.notification.controller;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+import site.easystartup.web.notification.domian.Notification;
+import site.easystartup.web.notification.repo.NotificationRepo;
+import site.easystartup.web.notification.service.NotificationService;
+
+import java.security.Principal;
+import java.util.List;
+
+@RestController
+@RequiredArgsConstructor(onConstructor_ = @Autowired)
+public class NotificationRestController {
+    private final NotificationService notificationService;
+
+    @GetMapping("/notifications/{username}")
+    public ResponseEntity<List<Notification>> notification(@PathVariable String username, Principal principal) {
+        return ResponseEntity.ok().body(notificationService.getNotificationByRecipient(username, principal));
+    }
+
+    @DeleteMapping("/notifications/{id}/delete")
+    public void delete(@PathVariable long id,
+                       Principal principal) {
+        notificationService.delete(id, principal);
+    }
+}

src/main/java/site/easystartup/web/notification/domian/Notification.java

@@ -0,0 +1,17 @@
+package site.easystartup.web.notification.domian;
+
+import lombok.*;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Getter
+@Setter
+@ToString
+@Entity
+public class Notification {
+    @Id
+    private long id;
+    private String text;
+    private String recipient;
+}

src/main/java/site/easystartup/web/notification/event/EventHandler.java

@@ -0,0 +1,12 @@
+package site.easystartup.web.notification.event;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+
+@Target(ElementType.METHOD)
+public @interface EventHandler {
+}

src/main/java/site/easystartup/web/notification/event/NotificationEvent.java

@@ -0,0 +1,9 @@
+package site.easystartup.web.notification.event;
+
+public interface NotificationEvent {
+    void invoke();
+
+    String getRecipient();
+
+    String getMessage();
+}

src/main/java/site/easystartup/web/notification/event/NotificationEventManager.java

@@ -0,0 +1,36 @@
+package site.easystartup.web.notification.event;
+
+import org.springframework.context.annotation.Scope;
+import org.springframework.stereotype.Component;
+
+import java.lang.reflect.InvocationTargetException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+@Component
+@Scope("singleton")
+public class NotificationEventManager {
+    private List<NotificationListener> listeners = new ArrayList<>();
+
+    public void registerListener(NotificationListener listener) {
+        listeners.add(listener);
+    }
+
+    public void removeListener(NotificationListener listener) {
+        listeners.remove(listener);
+    }
+
+    public void notifyListeners(Class<? extends NotificationEvent> event) {
+        listeners.forEach(listener -> Arrays.stream(listener.getClass().getMethods()).
+                filter(m -> m.isAnnotationPresent(EventHandler.class)).forEach(method -> {
+                    if (method.getParameterTypes()[0].equals(event.getClass())) {
+                        try {
+                            method.invoke(listener, event);
+                        } catch (IllegalAccessException | InvocationTargetException e) {
+                            throw new RuntimeException(e);
+                        }
+                    }
+                }));
+    }
+}

src/main/java/site/easystartup/web/notification/event/NotificationListener.java

@@ -0,0 +1,4 @@
+package site.easystartup.web.notification.event;
+
+public interface NotificationListener {
+}

src/main/java/site/easystartup/web/notification/event/realtime/RealTimeListener.java

@@ -0,0 +1,26 @@
+package site.easystartup.web.notification.event.realtime;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Autowired;
+import site.easystartup.web.notification.domian.Notification;
+import site.easystartup.web.notification.event.EventHandler;
+import site.easystartup.web.notification.event.NotificationEvent;
+import site.easystartup.web.notification.event.NotificationListener;
+import site.easystartup.web.notification.repo.NotificationRepo;
+import site.easystartup.web.notification.service.NotificationService;
+import site.easystartup.web.post.domain.event.RepostEvent;
+
+@RequiredArgsConstructor(onConstructor_ = @Autowired)
+public class RealTimeListener implements NotificationListener {
+    private final NotificationService notificationService;
+
+    private final NotificationRepo repo;
+
+    @EventHandler
+    public void onEvent(NotificationEvent event) {
+        Notification notification = new Notification();
+        notification.setText(event.getMessage());
+        notification.setRecipient(event.getRecipient());
+        notificationService.sendNotification(repo.save(notification));
+    }
+}

src/main/java/site/easystartup/web/notification/repo/NotificationRepo.java

@@ -0,0 +1,7 @@
+package site.easystartup.web.notification.repo;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import site.easystartup.web.notification.domian.Notification;
+
+public interface NotificationRepo extends JpaRepository<Notification, Long> {
+}

src/main/java/site/easystartup/web/notification/service/NotificationService.java

@@ -0,0 +1,43 @@
+package site.easystartup.web.notification.service;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.messaging.simp.SimpMessagingTemplate;
+import org.springframework.stereotype.Component;
+import site.easystartup.web.exception.NoPermissionException;
+import site.easystartup.web.notification.domian.Notification;
+import site.easystartup.web.notification.repo.NotificationRepo;
+import site.easystartup.web.service.UserService;
+
+import java.security.Principal;
+import java.util.List;
+
+@Component
+@RequiredArgsConstructor(onConstructor_ = @Autowired)
+public class NotificationService {
+    private final SimpMessagingTemplate messagingTemplate;
+
+    private final NotificationRepo repo;
+
+    private final UserService userService;
+
+    public void sendNotification(Notification notification) {
+        messagingTemplate.convertAndSendToUser(notification.getRecipient(), "queue/notification", notification);
+    }
+
+    public List<Notification> getNotificationByRecipient(String recipient, Principal principal) {
+        if(!recipient.equals(principal.getName()) && !userService.getUserByPrincipal(principal).isAdmin())
+            throw new NoPermissionException(String.format("User %s dont have access to see notifications of user %s",
+                    principal.getName(), recipient));
+        return repo.findAll().stream()
+                .filter(notification -> notification.getRecipient().equals(recipient)).toList();
+    }
+
+    public void delete(long id, Principal principal) {
+        Notification notification = repo.findById(id).orElseThrow();
+        if(!notification.getRecipient().equals(principal.getName()) && !userService.getUserByPrincipal(principal).isAdmin())
+            throw new NoPermissionException(String.format("User %s dont have access to delete notifications of user %s",
+                    principal.getName(), notification.getRecipient()));
+        repo.delete(notification);
+    }
+}