public synchronized RpcContent addKey(String key) {
        RpcContent rpcContent = createRpcContent();
        map.put(key, rpcContent);
        return rpcContent;
    }
public synchronized RpcContent addKey(String key) {
        RpcContent rpcContent = createRpcContent();
        map.put(key, rpcContent);
        return rpcContent;
    }
public synchronized RpcContent addKey ( String key ) { RpcContent rpcContent = createRpcContent ( ) ; map . put ( key , rpcContent ) ; return rpcContent ; }
并发可能会出重复添加

@param key key
@return RpcContent
并发可能会出重复添加