src/test/org/apache/commons/io/output/TaggedOutputStreamTest.java

/*
 * 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.commons.io.output;

import java.io.IOException;
import java.io.OutputStream;
import java.util.UUID;

import org.apache.commons.io.TaggedIOException;

import junit.framework.TestCase;

/**
 * JUnit Test Case for {@link TaggedOutputStream}.
 */
public class TaggedOutputStreamTest extends TestCase {

    public void testNormalStream() {
        try {
            ByteArrayOutputStream buffer = new ByteArrayOutputStream(); 
            OutputStream stream = new TaggedOutputStream(buffer);
            stream.write('a');
            stream.write(new byte[] { 'b' });
            stream.write(new byte[] { 'c' }, 0, 1);
            stream.flush();
            stream.close();
            assertEquals(3, buffer.size());
            assertEquals('a', buffer.toByteArray()[0]);
            assertEquals('b', buffer.toByteArray()[1]);
            assertEquals('c', buffer.toByteArray()[2]);
        } catch (IOException e) {
            fail("Unexpected exception thrown");
        }
    }

    public void testBrokenStream() {
        IOException exception = new IOException("test exception");
        TaggedOutputStream stream =
            new TaggedOutputStream(new BrokenOutputStream(exception));

        // Test the write() method
        try {
            stream.write('x');
            fail("Expected exception not thrown.");
        } catch (IOException e) {
            assertTrue(stream.isCauseOf(e));
            try {
                stream.throwIfCauseOf(e);
                fail("Expected exception not thrown.");
            } catch (IOException e2) {
                assertEquals(exception, e2);
            }
        }

        // Test the flush() method
        try {
            stream.flush();
            fail("Expected exception not thrown.");
        } catch (IOException e) {
            assertTrue(stream.isCauseOf(e));
            try {
                stream.throwIfCauseOf(e);
                fail("Expected exception not thrown.");
            } catch (IOException e2) {
                assertEquals(exception, e2);
            }
        }

        // Test the close() method
        try {
            stream.close();
            fail("Expected exception not thrown.");
        } catch (IOException e) {
            assertTrue(stream.isCauseOf(e));
            try {
                stream.throwIfCauseOf(e);
                fail("Expected exception not thrown.");
            } catch (IOException e2) {
                assertEquals(exception, e2);
            }
        }
    }

    public void testOtherException() {
        IOException exception = new IOException("test exception");
        OutputStream closed = new ClosedOutputStream();
        TaggedOutputStream stream = new TaggedOutputStream(closed);

        assertFalse(stream.isCauseOf(exception));
        assertFalse(stream.isCauseOf(
                new TaggedIOException(exception, UUID.randomUUID())));

        try {
            stream.throwIfCauseOf(exception);
        } catch (IOException e) {
            fail("Unexpected exception thrown");
        }

        try {
            stream.throwIfCauseOf(
                    new TaggedIOException(exception, UUID.randomUUID()));
        } catch (IOException e) {
            fail("Unexpected exception thrown");
        }
    }

}