RetryException.java

/*
 * Copyright 2012-2015 Ray Holder
 *
 * 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.
 */

package me.hao0.antares.common.retry;

import javax.annotation.Nonnull;
import javax.annotation.concurrent.Immutable;

import static com.google.common.base.Preconditions.checkNotNull;

/**
 * An exception indicating that none of the attempts of the {@link Retryer}
 * succeeded. If the last {@link Attempt} resulted in an Exception, it is set as
 * the cause of the {@link RetryException}.
 *
 * @author JB
 */
@Immutable
public final class RetryException extends Exception {

    private final int numberOfFailedAttempts;
    private final Attempt<?> lastFailedAttempt;

    /**
     * If the last {@link Attempt} had an Exception, ensure it is available in
     * the stack trace.
     *
     * @param numberOfFailedAttempts times we've tried and failed
     * @param lastFailedAttempt      what happened the last time we failed
     */
    public RetryException(int numberOfFailedAttempts, @Nonnull Attempt<?> lastFailedAttempt) {
        this("Retrying failed to complete successfully after " + numberOfFailedAttempts + " attempts.", numberOfFailedAttempts, lastFailedAttempt);
    }

    /**
     * If the last {@link Attempt} had an Exception, ensure it is available in
     * the stack trace.
     *
     * @param message                Exception description to be added to the stack trace
     * @param numberOfFailedAttempts times we've tried and failed
     * @param lastFailedAttempt      what happened the last time we failed
     */
    public RetryException(String message, int numberOfFailedAttempts, Attempt<?> lastFailedAttempt) {
        super(message, checkNotNull(lastFailedAttempt, "Last attempt was null").hasException() ? lastFailedAttempt.getExceptionCause() : null);
        this.numberOfFailedAttempts = numberOfFailedAttempts;
        this.lastFailedAttempt = lastFailedAttempt;
    }

    /**
     * Returns the number of failed attempts
     *
     * @return the number of failed attempts
     */
    public int getNumberOfFailedAttempts() {
        return numberOfFailedAttempts;
    }

    /**
     * Returns the last failed attempt
     *
     * @return the last failed attempt
     */
    public Attempt<?> getLastFailedAttempt() {
        return lastFailedAttempt;
    }
}