ActiveUser.java

package com.huixinpn.dionysus.service.impl;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.huixinpn.dionysus.repository.chat.RoomRepository;
import com.huixinpn.dionysus.repository.user.UserRepository;
import com.huixinpn.dionysus.service.ActiveUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.HashMap;
import java.util.Set;
import java.util.concurrent.TimeUnit;

/**
 * Created by huanghao on 7/13/15.
 */

@Service
public class ActiveUser implements ActiveUserService {
    @Autowired
    private UserRepository userRepository;

    @Autowired
    private RoomRepository roomRepository;


    private LoadingCache<String, RoomState> statsByRoom = CacheBuilder.newBuilder()
            .expireAfterAccess(5, TimeUnit.MINUTES)
            .maximumSize(50)
            .build(new CacheLoader<String, RoomState>() {

                @Override
                public RoomState load(String key) throws Exception {
                    return new RoomState(userRepository);
                }

            });

    @Override
    public void mark(String roomId, String username) {
        statsByRoom.getUnchecked(roomId).mark(username);
    }

    @Override
    public HashMap<String, UserState> getActiveUsers(String roomId) {
        return statsByRoom.getUnchecked(roomId).getActiveUsers();
    }

    @Override
    public Set<String> getActiveRooms() {
        return statsByRoom.asMap().keySet();
    }

    @Override
    public UserState getActiveUser(String roomId, String username) {
        return statsByRoom.getUnchecked(roomId).getActiveUsers().get(username);
    }
}