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.x.async.AsyncResult; import org.apache.zookeeper.KeeperException; import java.util.Objects; import java.util.Optional; public class AsyncResultImpl<T> implements AsyncResult<T> { private final T value; private final KeeperException.Code code; private final Throwable exception; public AsyncResultImpl() { this(null, KeeperException.Code.OK, null); } public AsyncResultImpl(KeeperException.Code code) { this(null, code, null); } public AsyncResultImpl(T value) { this(value, KeeperException.Code.OK, null); } public AsyncResultImpl(Throwable exception) { this(null, KeeperException.Code.SYSTEMERROR, exception); } private AsyncResultImpl(T value, KeeperException.Code code, Throwable exception) { this.value = value; this.exception = exception; this.code = Objects.requireNonNull(code, "error cannot be null"); } public T getRawValue() { return value; } public Optional<T> getValue() { return Optional.ofNullable(value); } public KeeperException.Code getCode() { return code; } public Throwable getRawException() { return exception; } public Optional<Throwable> getException() { return Optional.ofNullable(exception); } public void checkException() { if (exception != null) { throw new RuntimeException(exception); } } @Override public void checkError() { checkException(); if (code != KeeperException.Code.OK) { throw new RuntimeException(KeeperException.create(code)); } } @Override public boolean equals(Object o) { if (this == o) { return true; } if (o == null || getClass() != o.getClass()) { return false; } AsyncResultImpl<?> that = (AsyncResultImpl<?>) o; if (value != null ? !value.equals(that.value) : that.value != null) { return false; } //noinspection SimplifiableIfStatement if (code != that.code) { return false; } return exception != null ? exception.equals(that.exception) : that.exception == null; } @Override public int hashCode() { int result = value != null ? value.hashCode() : 0; result = 31 * result + code.hashCode(); result = 31 * result + (exception != null ? exception.hashCode() : 0); return result; } @Override public String toString() { return "AsyncResult{" + "value=" + value + ", code=" + code + ", exception=" + exception + '}'; } }