IIOProviderContextListenerTest.java

/*
 * Copyright (c) 2014, Harald Kuhr
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 * * Neither the name of the copyright holder nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.twelvemonkeys.servlet.image;

import static org.mockito.Mockito.mock;

import java.util.Locale;

import javax.imageio.ImageReader;
import javax.imageio.spi.IIORegistry;
import javax.imageio.spi.ImageReaderSpi;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

/**
 * IIOProviderContextListenerTest
 *
 * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
 * @author last modified by $Author: haraldk$
 * @version $Id: IIOProviderContextListenerTest.java,v 1.0 02.01.14 12:33 haraldk Exp$
 */
public class IIOProviderContextListenerTest {

    private final ServletContext context = mock(ServletContext.class);
    private  final ServletContextEvent initialized = new ServletContextEvent(context);
    private  final ServletContextEvent destroyed = new ServletContextEvent(context);

    @Test
    public void testContextInitialized() {
        ServletContextListener listener = new IIOProviderContextListener();
        listener.contextInitialized(initialized);
    }

    @Test
    public void testContextDestroyed() {
        ServletContextListener listener = new IIOProviderContextListener();
        listener.contextInitialized(initialized);
        listener.contextDestroyed(destroyed);
    }

    // Regression test for issue #29
    @Test
    public void testDestroyConcurrentModRegression() {
        ServletContextListener listener = new IIOProviderContextListener();
        listener.contextInitialized(initialized);

        ImageReaderSpi provider1 = new MockImageReaderSpiOne();
        ImageReaderSpi provider2 = new MockImageReaderSpiToo();

        // NOTE: Fake registering for simplicity, but it still exposes the original problem with de-registering
        IIORegistry registry = IIORegistry.getDefaultInstance();
        registry.registerServiceProvider(provider1);
        registry.registerServiceProvider(provider2);
        assertTrue(registry.contains(provider1));
        assertTrue(registry.contains(provider2));

        listener.contextDestroyed(destroyed);

        assertFalse(registry.contains(provider1));
        assertFalse(registry.contains(provider2));
    }

    private static abstract class MockImageReaderSpiBase extends ImageReaderSpi {
        @Override
        public boolean canDecodeInput(Object source) {
            return false;
        }

        @Override
        public ImageReader createReaderInstance(Object extension) {
            return null;
        }

        @Override
        public String getDescription(Locale locale) {
            return "I'm a mock. So don't mock me.";
        }
    }

    private static final class MockImageReaderSpiOne extends MockImageReaderSpiBase {
    }

    private static final class MockImageReaderSpiToo extends MockImageReaderSpiBase {
    }
}