| package org.apache.helix.zookeeper.zkclient; |
| |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| import org.apache.zookeeper.Watcher.Event.KeeperState; |
| |
| |
| public interface IZkStateListener { |
| |
| /** |
| * Called when the zookeeper connection state has changed. |
| * |
| * @param state the new zookeeper state. |
| * @throws Exception if any error occurs. |
| */ |
| void handleStateChanged(KeeperState state) throws Exception; |
| |
| /** |
| * Called after the zookeeper session has expired and a new session has been created. The new |
| * session id has to be passed in as the parameter. |
| * And you would have to re-create any ephemeral nodes here. This is a session aware operation. |
| * The ephemeral nodes have to be created within the expected session id, which means passed-in |
| * session id has to be checked with current zookeeper's session id. If the passed-in session id |
| * does not match current zookeeper's session id, ephemeral nodes should not be created. |
| * Otherwise, session race condition may occur and the newly created ephemeral nodes may not be in |
| * the expected session. |
| * |
| * @param sessionId the new session's id. The ephemeral nodes are expected to be created in this |
| * session. If this session id is expired, ephemeral nodes should not be created. |
| * @throws Exception if any error occurs. |
| */ |
| void handleNewSession(final String sessionId) throws Exception; |
| |
| /** |
| * Called when a session cannot be re-established. This should be used to implement connection |
| * failure handling e.g. retry to connect or pass the error up |
| * |
| * @param error |
| * The error that prevents a session from being established |
| * @throws Exception |
| * On any error. |
| */ |
| void handleSessionEstablishmentError(final Throwable error) throws Exception; |
| } |