com.forerunnergames.tools.common.Result.java Source code

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Here is the source code for com.forerunnergames.tools.common.Result.java

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/*
 * Copyright  2011 - 2013 Aaron Mahan
 * Copyright  2013 - 2016 Forerunner Games, LLC
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package com.forerunnergames.tools.common;

import com.google.common.base.Optional;

import javax.annotation.Nullable;

public class Result<T> {
    private final boolean isSuccessful;
    @Nullable
    private final T failureReason;

    protected Result(final boolean isSuccessful, @Nullable final T failureReason) {
        this.isSuccessful = isSuccessful;
        this.failureReason = failureReason;
    }

    public static <U> Result<U> success() {
        return new Result<>(true, null);
    }

    public static <V> Result<V> failure(final V failureReason) {
        Arguments.checkIsNotNull(failureReason, "failureReason");

        return new Result<>(false, failureReason);
    }

    public static boolean anyResultsFailed(final Iterable<Result<?>> results) {
        Arguments.checkIsNotNull(results, "results");
        Arguments.checkHasNoNullElements(results, "results");

        for (final Result<?> result : results) {
            if (result.failed())
                return true;
        }

        return false;
    }

    public static <V, R extends Result<V>> Optional<R> firstFailedFrom(final Iterable<R> results) {
        Arguments.checkIsNotNull(results, "results");
        Arguments.checkHasNoNullElements(results, "results");

        for (final R result : results) {
            if (result.failed())
                return Optional.of(result);
        }

        return Optional.absent();
    }

    @SafeVarargs
    public static <V, R extends Result<V>> Optional<R> firstFailedFrom(final R... results) {
        Arguments.checkIsNotNull(results, "results");
        Arguments.checkHasNoNullElements(results, "results");

        for (final R result : results) {
            if (result.failed())
                return Optional.of(result);
        }

        return Optional.absent();
    }

    public static <R extends Result<?>> Optional<R> firstGenericFailedFrom(final Iterable<R> results) {
        Arguments.checkIsNotNull(results, "results");
        Arguments.checkHasNoNullElements(results, "results");

        for (final R result : results) {
            if (result.failed())
                return Optional.of(result);
        }

        return Optional.absent();
    }

    @SafeVarargs
    public static <R extends Result<?>> Optional<R> firstGenericFailedFrom(final R... results) {
        Arguments.checkIsNotNull(results, "results");
        Arguments.checkHasNoNullElements(results, "results");

        for (final R result : results) {
            if (result.failed())
                return Optional.of(result);
        }

        return Optional.absent();
    }

    public static <V extends ReturnStatus<?>> boolean anyStatusFailed(final Iterable<V> results) {
        Arguments.checkIsNotNull(results, "results");
        Arguments.checkHasNoNullElements(results, "results");

        return firstFailedStatusFrom(results).isPresent();
    }

    public static <V extends ReturnStatus<?>> Optional<V> firstFailedStatusFrom(final Iterable<V> statuses) {
        Arguments.checkIsNotNull(statuses, "statuses");
        Arguments.checkHasNoNullElements(statuses, "statuses");

        for (final V status : statuses) {
            if (status.getResult().failed())
                return Optional.of(status);
        }

        return Optional.absent();
    }

    public boolean isSuccessful() {
        return isSuccessful;
    }

    public boolean succeeded() {
        return isSuccessful();
    }

    public boolean isFailure() {
        return !isSuccessful;
    }

    public boolean failed() {
        return isFailure();
    }

    public boolean failedBecauseOf(final T failureReason) {
        Arguments.checkIsNotNull(failureReason, "failureReason");

        return isFailure() && failureReasonIs(failureReason);
    }

    public boolean failureReasonIs(final T failureReason) {
        Arguments.checkIsNotNull(failureReason, "failureReason");

        return getFailureReason().equals(failureReason);
    }

    public T getFailureReason() {
        Preconditions.checkIsTrue(isFailure(), "Cannot get failure reason when result is successful.");

        return failureReason;
    }

    public interface ReturnStatus<R> {
        Result<R> getResult();
    }
}