VirtualFuture.java

/*
 *  * This file is part of the Hesperides distribution.
 *  * (https://github.com/voyages-sncf-technologies/hesperides)
 *  * Copyright (c) 2016 VSCT.
 *  *
 *  * Hesperides is free software: you can redistribute it and/or modify
 *  * it under the terms of the GNU General Public License as
 *  * published by the Free Software Foundation, version 3.
 *  *
 *  * Hesperides is distributed in the hope that it will be useful, but
 *  * WITHOUT ANY WARRANTY; without even the implied warranty of
 *  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 *  * General Public License for more details.
 *  *
 *  * You should have received a copy of the GNU General Public License
 *  * along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 */
package com.vsct.dt.hesperides.applications.virtual;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * Created by emeric_martineau on 09/02/2017.
 */
public class VirtualFuture<T> implements Future<T> {
    private interface VirtualResult<T> {
        T get() throws Exception;
    }

    private VirtualResult<T> vr;

    public VirtualFuture(final Callable<T> task) {
        vr = () -> task.call();
    }

    public VirtualFuture(final Runnable task, final T result) {
        vr = () -> result;
    }

    public VirtualFuture(final Runnable task) {
        vr = () -> {
            task.run();
            return null;
        };
    }

    @Override
    public boolean cancel(final boolean mayInterruptIfRunning) {
        return false;
    }

    @Override
    public boolean isCancelled() {
        return false;
    }

    @Override
    public boolean isDone() {
        return false;
    }

    @Override
    public T get() throws InterruptedException, ExecutionException {
        try {
            return vr.get();
        } catch (InterruptedException | ExecutionException e) {
            throw e;
        } catch (Exception e) {
            throw new ExecutionException(e);
        }
    }

    @Override
    public T get(final long timeout, final TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
        try {
            return vr.get();
        } catch (InterruptedException | ExecutionException e) {
            throw e;
        } catch (Exception e) {
            throw new ExecutionException(e);
        }
    }
}