创建单例缓存map集合

1.项目中需要把数据和websocket链接缓存到map中

import java.util.Map; 
import java.util.concurrent.ConcurrentHashMap; 
 
import okhttp3.WebSocket; 
 
public class BufferMap { 
	private static BufferMap bufferMap; 
	private static Map<String, String> mapChacheMsgItems; 
	private static Map<String, WebSocket> webSocketMap; 
 
	private BufferMap() { 
		mapChacheMsgItems = new ConcurrentHashMap<String, String>(); 
		webSocketMap = new ConcurrentHashMap<String, WebSocket>(); 
	} 
 
	public static BufferMap getInstance() { 
		if (bufferMap == null) { 
			synchronized (BufferMap.class) { 
				if (bufferMap == null) { 
					bufferMap = new BufferMap(); 
				} 
			} 
		} 
		return bufferMap; 
	} 
 
	public WebSocket getWebSocket(String key) { 
		if (webSocketMap.containsKey(key)) { 
			return webSocketMap.get(key); 
		} 
		return null; 
	} 
 
	public WebSocket putWebSocket(String key, WebSocket webSocket) { 
		return webSocketMap.put(key, webSocket); 
	} 
 
	public Map<String, String> getChacheMsgItems() { 
		return mapChacheMsgItems; 
	} 
 
	public String getCacheMsgItem(String key) { 
		if (mapChacheMsgItems.containsKey(key)) { 
			return mapChacheMsgItems.get(key); 
		} 
		return null; 
	} 
 
	public String putMapChacheMsgItems(String key, String msg) { 
		return mapChacheMsgItems.put(key, msg); 
	} 
 
	public void removeCacheMsgItem(String key) { 
		if (mapChacheMsgItems.containsKey(key)) { 
			mapChacheMsgItems.remove(key); 
		} 
	} 
 
	public void clearCache() { 
		mapChacheMsgItems.clear(); 
	} 
}