| /* |
| * 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.flink.util; |
| |
| import org.apache.flink.util.function.CheckedSupplier; |
| |
| import javax.annotation.Nullable; |
| |
| import java.io.IOException; |
| import java.io.ObjectInputStream; |
| import java.io.ObjectOutputStream; |
| import java.io.Serializable; |
| import java.util.Objects; |
| |
| import static org.apache.flink.util.Preconditions.checkNotNull; |
| |
| /** |
| * Wrapper around an object representing either a success (with a given value) or a failure cause. |
| */ |
| public class OptionalFailure<T> implements Serializable { |
| private static final long serialVersionUID = 1L; |
| |
| @Nullable private transient T value; |
| |
| @Nullable private Throwable failureCause; |
| |
| private OptionalFailure(@Nullable T value, @Nullable Throwable failureCause) { |
| this.value = value; |
| this.failureCause = failureCause; |
| } |
| |
| public static <T> OptionalFailure<T> of(T value) { |
| return new OptionalFailure<>(value, null); |
| } |
| |
| public static <T> OptionalFailure<T> ofFailure(Throwable failureCause) { |
| return new OptionalFailure<>(null, failureCause); |
| } |
| |
| /** |
| * @return wrapped {@link OptionalFailure} returned by {@code valueSupplier} or wrapped failure |
| * if {@code valueSupplier} has thrown an {@link Exception}. |
| */ |
| public static <T> OptionalFailure<T> createFrom(CheckedSupplier<T> valueSupplier) { |
| try { |
| return of(valueSupplier.get()); |
| } catch (Exception ex) { |
| return ofFailure(ex); |
| } |
| } |
| |
| /** @return stored value or throw a {@link FlinkException} with {@code failureCause}. */ |
| public T get() throws FlinkException { |
| if (value != null) { |
| return value; |
| } |
| checkNotNull(failureCause); |
| throw new FlinkException(failureCause); |
| } |
| |
| /** @return same as {@link #get()} but throws a {@link FlinkRuntimeException}. */ |
| public T getUnchecked() throws FlinkRuntimeException { |
| if (value != null) { |
| return value; |
| } |
| checkNotNull(failureCause); |
| throw new FlinkRuntimeException(failureCause); |
| } |
| |
| public Throwable getFailureCause() { |
| return checkNotNull(failureCause); |
| } |
| |
| public boolean isFailure() { |
| return failureCause != null; |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(value, failureCause); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (obj == null) { |
| return false; |
| } |
| if (obj == this) { |
| return true; |
| } |
| if (!(obj instanceof OptionalFailure<?>)) { |
| return false; |
| } |
| OptionalFailure<?> other = (OptionalFailure<?>) obj; |
| return Objects.equals(value, other.value) |
| && Objects.equals(failureCause, other.failureCause); |
| } |
| |
| private void writeObject(ObjectOutputStream stream) throws IOException { |
| stream.defaultWriteObject(); |
| stream.writeObject(value); |
| } |
| |
| private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException { |
| stream.defaultReadObject(); |
| value = (T) stream.readObject(); |
| } |
| |
| @Override |
| public String toString() { |
| return getClass().getSimpleName() |
| + "{value=" |
| + value |
| + ", failureCause=" |
| + failureCause |
| + "}"; |
| } |
| } |