flink-formats/flink-sequence-file/src/main/java/org/apache/flink/formats/sequencefile/SerializableHadoopConfiguration.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 java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

/**
 * Wrapper class for serialization of {@link Configuration}.
 */
class SerializableHadoopConfiguration implements Serializable {

	private static final long serialVersionUID = 1L;

	private transient Configuration hadoopConfig;

	SerializableHadoopConfiguration(Configuration hadoopConfig) {
		this.hadoopConfig = hadoopConfig;
	}

	Configuration get() {
		return this.hadoopConfig;
	}

	// --------------------
	private void writeObject(ObjectOutputStream out) throws IOException {
		this.hadoopConfig.write(out);
	}

	private void readObject(ObjectInputStream in) throws IOException {
		final Configuration config = new Configuration();
		config.readFields(in);

		if (this.hadoopConfig == null) {
			this.hadoopConfig = config;
		}
	}
}