flink-formats/flink-sequence-file/src/test/java/org/apache/flink/formats/sequencefile/SerializableHadoopConfigurationTest.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.flink.formats.sequencefile;

import org.apache.hadoop.conf.Configuration;
import org.hamcrest.Description;
import org.hamcrest.TypeSafeMatcher;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

/**
 * Tests for the {@link SerializableHadoopConfiguration}.
 */
public class SerializableHadoopConfigurationTest {

	private static final String TEST_KEY = "test-key";

	private static final String TEST_VALUE = "test-value";

	private Configuration configuration;

	@Before
	public void createConfigWithCustomProperty() {
		this.configuration = new Configuration();
		configuration.set(TEST_KEY, TEST_VALUE);
	}

	@Test
	public void customPropertiesSurviveSerializationDeserialization() throws IOException, ClassNotFoundException {
		final SerializableHadoopConfiguration serializableConfigUnderTest = new SerializableHadoopConfiguration(configuration);
		final byte[] serializedConfigUnderTest = serializeAndGetBytes(serializableConfigUnderTest);
		final SerializableHadoopConfiguration deserializableConfigUnderTest = deserializeAndGetConfiguration(serializedConfigUnderTest);

		Assert.assertThat(deserializableConfigUnderTest.get(), hasTheSamePropertiesAs(configuration));
	}

	// ----------------------------------------	Matchers ---------------------------------------- //

	private static TypeSafeMatcher<Configuration> hasTheSamePropertiesAs(final Configuration expectedConfig) {
		return new TypeSafeMatcher<Configuration>() {
			@Override
			protected boolean matchesSafely(Configuration actualConfig) {
				final String value = actualConfig.get(TEST_KEY);
				return actualConfig != expectedConfig && value != null && expectedConfig.get(TEST_KEY).equals(value);
			}

			@Override
			public void describeTo(Description description) {
				description.appendText("a Hadoop Configuration with property: key=")
						.appendValue(TEST_KEY)
						.appendText(" and value=")
						.appendValue(TEST_VALUE);
			}
		};
	}

	// ----------------------------------------	Helper Methods ---------------------------------------- //

	private byte[] serializeAndGetBytes(SerializableHadoopConfiguration serializableConfigUnderTest) throws IOException {
		try (
				ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
				ObjectOutputStream out = new ObjectOutputStream(byteStream)
		) {
			out.writeObject(serializableConfigUnderTest);
			out.flush();
			return byteStream.toByteArray();
		}
	}

	private SerializableHadoopConfiguration deserializeAndGetConfiguration(byte[] serializedConfig) throws IOException, ClassNotFoundException {
		try (ObjectInputStream in = new ObjectInputStream(new ByteArrayInputStream(serializedConfig))) {
			return (SerializableHadoopConfiguration) in.readObject();
		}
	}
}