ResettableInputStreamTest.java

/*
 * Copyright 2010-2017 Amazon.com, Inc. or its affiliates. All Rights
 * Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file 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 com.amazonaws.internal;

import static com.amazonaws.util.FileUtils.generateRandomAsciiFile;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.channels.ClosedChannelException;

import org.apache.commons.io.IOUtils;
import org.junit.BeforeClass;
import org.junit.Test;

public class ResettableInputStreamTest {

    private static File file;

    @BeforeClass
    public static void setup() throws IOException {
        file = generateRandomAsciiFile(100);
    }

    @Test
    public void testFileInputStream() throws IOException {
        InputStream is = new FileInputStream(file);
        assertFalse(is.markSupported());
        final String content = IOUtils.toString(is);
        final String content2 = IOUtils.toString(is);
        assertTrue(content.length() == 100);
        assertEquals(content2, "");
        is.close();
    }

    @Test
    public void testResetInputStreamWithFile() throws IOException {
        ResettableInputStream is = new ResettableInputStream(file);
        assertTrue(is.markSupported());
        final String content = IOUtils.toString(is);
        is.reset();
        final String content2 = IOUtils.toString(is);
        assertTrue(content.length() == 100);
        assertEquals(content, content2);
        is.close();
        assertEquals(file, is.getFile());
    }

    @Test
    public void testResetFileInputStream() throws IOException {
        ResettableInputStream is = new ResettableInputStream(
                new FileInputStream(file));
        assertTrue(is.markSupported());
        final String content = IOUtils.toString(is);
        is.reset();
        final String content2 = IOUtils.toString(is);
        assertTrue(content.length() == 100);
        assertEquals(content, content2);
        is.close();
        assertNull(is.getFile());
    }

    @Test
    public void testMarkAndResetWithFile() throws IOException {
        ResettableInputStream is = new ResettableInputStream(file);
        is.read(new byte[10]);
        is.mark(-1);
        final String content = IOUtils.toString(is);
        is.reset();
        final String content2 = IOUtils.toString(is);
        assertTrue(content.length() == 90);
        assertEquals(content, content2);
        is.close();
    }

    @Test
    public void testMarkAndResetFileInputStream() throws IOException {
        ResettableInputStream is = new ResettableInputStream(new FileInputStream(file));
        is.read(new byte[10]);
        is.mark(-1);
        final String content = IOUtils.toString(is);
        is.reset();
        final String content2 = IOUtils.toString(is);
        assertTrue(content.length() == 90);
        assertEquals(content, content2);
        is.close();
    }

    @Test
    public void testResetWithClosedFile() throws IOException {
        ResettableInputStream is = new ResettableInputStream(file).disableClose();
        final String content = IOUtils.toString(is);
        is.close();
        is.reset(); // survive a close operation!
        final String content2 = IOUtils.toString(is);
        assertTrue(content.length() == 100);
        assertEquals(content, content2);
        is.release();
    }

    @Test(expected=ClosedChannelException.class)
    public void negativeTestResetWithClosedFile() throws IOException {
        ResettableInputStream is = new ResettableInputStream(file);
        is.close();
        is.reset();
    }

    @Test
    public void testMarkAndResetWithClosedFile() throws IOException {
        ResettableInputStream is = new ResettableInputStream(file).disableClose();
        is.read(new byte[10]);
        is.mark(-1);
        final String content = IOUtils.toString(is);
        is.close();
        is.reset(); // survive a close operation!
        final String content2 = IOUtils.toString(is);
        assertTrue(content.length() == 90);
        assertEquals(content, content2);
        is.release();
    }

    @Test(expected=ClosedChannelException.class)
    public void testMarkAndResetClosedFileInputStream() throws IOException {
        ResettableInputStream is = new ResettableInputStream(new FileInputStream(file));
        is.close();
        is.reset(); // cannot survive a close if not disabled
    }
}