script.js

package com.chat;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.messaging.handler.annotation.MessageMapping;
import org.springframework.messaging.handler.annotation.SendTo;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.stereotype.Controller;
import org.springframework.web.socket.config.annotation.*;
import jakarta.persistence.*;
import java.time.LocalDateTime;

@SpringBootApplication
public class ChatApplication {
    public static void main(String[] args) {
        SpringApplication.run(ChatApplication.class, args);
    }
}

// 1. DATABASE ENTITY
@Entity
class ChatMessage {
    @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String sender;
    private String content;
    private LocalDateTime timestamp = LocalDateTime.now();

    public ChatMessage() {}
    public ChatMessage(String sender, String content) { this.sender = sender; this.content = content; }
    // Getters/Setters
    public String getSender() { return sender; }
    public void setSender(String sender) { this.sender = sender; }
    public String getContent() { return content; }
    public void setContent(String content) { this.content = content; }
}

// 2. REPOSITORY
interface MessageRepository extends JpaRepository<ChatMessage, Long> {}

// 3. WEBSOCKET CONFIG
@Configuration
@EnableWebSocketMessageBroker
class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
    @Override
    public void configureMessageBroker(MessageBrokerRegistry config) {
        config.enableSimpleBroker("/topic");
        config.setApplicationDestinationPrefixes("/app");
    }
    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/ws").withSockJS();
    }
}

// 4. CONTROLLER
@Controller
class ChatController {
    private final MessageRepository repository;
    public ChatController(MessageRepository repository) { this.repository = repository; }

    @MessageMapping("/chat.sendMessage")
    @SendTo("/topic/public")
    public ChatMessage sendMessage(ChatMessage chatMessage) {
        return repository.save(chatMessage);
    }
}