/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.tika.io;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.junit.Test;
import static org.junit.Assert.assertEquals;;
/**
* Test cases for the {@link LookaheadInputStream} class.
*/
public class LookaheadInputStreamTest {
@Test
public void testNullStream() throws IOException {
InputStream lookahead = new LookaheadInputStream(null, 100);
assertEquals(-1, lookahead.read());
}
@Test
public void testEmptyStream() throws IOException {
InputStream stream = new ByteArrayInputStream(new byte[0]);
InputStream lookahead = new LookaheadInputStream(stream, 100);
assertEquals(-1, lookahead.read());
lookahead.close();
assertEquals(-1, stream.read());
}
@Test
public void testBasicLookahead() throws IOException {
InputStream stream =
new ByteArrayInputStream(new byte[] { 'a', 'b', 'c' });
InputStream lookahead = new LookaheadInputStream(stream, 2);
assertEquals('a', lookahead.read());
assertEquals('b', lookahead.read());
assertEquals(-1, lookahead.read());
lookahead.close();
assertEquals('a', stream.read());
assertEquals('b', stream.read());
assertEquals('c', stream.read());
assertEquals(-1, stream.read());
}
@Test
public void testZeroLookahead() throws IOException {
InputStream stream =
new ByteArrayInputStream(new byte[] { 'a', 'b', 'c' });
InputStream lookahead = new LookaheadInputStream(stream, 0);
assertEquals(-1, lookahead.read());
lookahead.close();
assertEquals('a', stream.read());
assertEquals('b', stream.read());
assertEquals('c', stream.read());
assertEquals(-1, stream.read());
}
@Test
public void testMarkLookahead() throws IOException {
InputStream stream =
new ByteArrayInputStream(new byte[] { 'a', 'b', 'c' });
InputStream lookahead = new LookaheadInputStream(stream, 2);
lookahead.mark(1);
assertEquals('a', lookahead.read());
lookahead.reset();
assertEquals('a', lookahead.read());
lookahead.mark(2);
assertEquals('b', lookahead.read());
assertEquals(-1, lookahead.read());
lookahead.reset();
assertEquals('b', lookahead.read());
assertEquals(-1, lookahead.read());
lookahead.close();
assertEquals('a', stream.read());
assertEquals('b', stream.read());
assertEquals('c', stream.read());
assertEquals(-1, stream.read());
}
@Test
public void testSkipLookahead() throws IOException {
InputStream stream =
new ByteArrayInputStream(new byte[] { 'a', 'b', 'c' });
InputStream lookahead = new LookaheadInputStream(stream, 2);
assertEquals(1, lookahead.skip(1));
assertEquals('b', lookahead.read());
assertEquals(0, lookahead.skip(1));
assertEquals(-1, lookahead.read());
lookahead.close();
assertEquals('a', stream.read());
assertEquals('b', stream.read());
assertEquals('c', stream.read());
assertEquals(-1, stream.read());
}
}