Java tutorial
/* * Copyright 1999-2015 dangdang.com. * <p> * Licensed 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. * </p> */ package com.dangdang.ddframe.job.cloud.scheduler.ha; import com.dangdang.ddframe.job.reg.base.CoordinatorRegistryCenter; import com.google.common.base.Optional; import com.google.common.base.Strings; import lombok.RequiredArgsConstructor; /** * FrameworkID ?. * * @author gaohongtao */ @RequiredArgsConstructor public class FrameworkIDService { private final CoordinatorRegistryCenter regCenter; /** * ?FrameworkID,?. * * @return ?FrameworkID? */ public Optional<String> fetch() { String frameworkId = regCenter.getDirectly(HANode.FRAMEWORK_ID_NODE); return Strings.isNullOrEmpty(frameworkId) ? Optional.<String>absent() : Optional.of(frameworkId); } /** * ?FrameworkID. * * @param id FrameworkID */ public void save(final String id) { if (!regCenter.isExisted(HANode.FRAMEWORK_ID_NODE)) { regCenter.persist(HANode.FRAMEWORK_ID_NODE, id); } } }