CODEWITHSUNDEEP
springspring-mvcspring-bootspring-data
Boaris
Boaris

Reputation: 5226

Store data not in database

I want to implement simple chat but store them only during server work. I don't want to store them in database, just like in List or Map. How to?

Upvotes: 1

Views: 1633

Answers (1)

Zergleb
Zergleb

Reputation: 2312

This solution works for "Simple" chat as you explained.

There isn't much information on how you had built this before so I'm just going to explain how to have an Application scoped bean that can be injected into other beans to handle storing chat.

You can configure a Service to store this information.

ChatHistoryService.java

@Service
@Scope("application")//This is the key this will keep the chatHistory alive for the length of the running application(As long as you don't have multiple instances deployed(But as you said it's simple so it shouldn't)
public class ChatHistoryService {

    List<String> chatHistory = new LinkedList<>();//Use LinkedList to maintain order of input

    public void storeChatMessage(String chatString) {
        chatHistory.add(chatString);
    }

    public List<String> getChatHistory() {
        //I would highly suggest creating a defensive copy of the chat here so it can't be modified. 
        return Collections.unmodifiableList(chatHistory);
    }

}

YourChatController.java

@Controller
public class YourChatController {

    @Autowired
    ChatHistoryService historyService;

    ...I'm assuming you already have chat logic but you aren't storing the chat here is where that would go

    ...When chat comes in call historyService.storeChatMessage(chatMessage);

    ...When you want your chat call historyService.getChatHistory();

}

Once again keep in mind that this really only works for a simple application. If it's distributed there will be different chat histories per instance of the application at that point you could look into a distributed cache.

In any case don't go beyond simple with this implementation.

If you look here it will give you an idea of several caches that work with spring boot.

https://github.com/spring-projects/spring-boot/tree/master/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cache

Upvotes: 4

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