Java tutorial
/** * 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. */ package org.apache.curator.x.async.details; import org.apache.curator.framework.api.CuratorEvent; import org.apache.curator.framework.api.transaction.CuratorTransactionResult; import org.apache.zookeeper.KeeperException; import org.apache.zookeeper.data.ACL; import org.apache.zookeeper.data.Stat; import java.util.List; import java.util.concurrent.Callable; import java.util.function.Function; class BackgroundProcs { static final BackgroundProc<String> nameProc = makeProc(CuratorEvent::getName); static final BackgroundProc<String> pathProc = makeProc(CuratorEvent::getPath); static final BackgroundProc<Void> ignoredProc = makeProc(e -> null); static final BackgroundProc<byte[]> dataProc = makeProc(CuratorEvent::getData); static final BackgroundProc<Stat> statProc = makeProc(CuratorEvent::getStat); static final BackgroundProc<Stat> safeStatProc = (event, future) -> { if ((event.getResultCode() == 0) || (event.getResultCode() == KeeperException.Code.NONODE.intValue())) { future.complete(event.getStat()); } else { future.completeExceptionally( KeeperException.create(KeeperException.Code.get(event.getResultCode()), event.getPath())); } return null; }; static final BackgroundProc<List<String>> childrenProc = makeProc(CuratorEvent::getChildren); static final BackgroundProc<List<ACL>> aclProc = makeProc(CuratorEvent::getACLList); static final BackgroundProc<List<CuratorTransactionResult>> opResultsProc = makeProc( CuratorEvent::getOpResults); static <T> BackgroundProc<T> makeProc(Function<CuratorEvent, T> proc) { return (event, future) -> { if (event.getResultCode() == 0) { future.complete(proc.apply(event)); } else { future.completeExceptionally( KeeperException.create(KeeperException.Code.get(event.getResultCode()), event.getPath())); } return null; }; } static <T> InternalCallback<T> safeCall(InternalCallback<T> callback, Callable<?> proc) { try { proc.call(); } catch (Exception e) { callback.toCompletableFuture().completeExceptionally(e); } return callback; } BackgroundProcs() { } }