/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed 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 eu.stratosphere.nephele.util;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import eu.stratosphere.core.io.StringRecord;
/**
* Auxiliary class to (de)serialize enumeration values.
*
*/
public final class EnumUtils {
/**
* Private constructor to overwrite public one.
*/
private EnumUtils() {
}
/**
* Reads a value from the given enumeration from the specified input stream.
*
* @param <T>
* the type of the enumeration
* @param in
* the input stream to read from
* @param enumType
* the class of the enumeration
* @return the value of the given enumeration read from the input stream
* @throws IOException
* thrown if any error occurred while reading data from the stream
*/
public static <T extends Enum<T>> T readEnum(final DataInput in, final Class<T> enumType) throws IOException {
if (!in.readBoolean()) {
return null;
}
return T.valueOf(enumType, StringRecord.readString(in));
}
/**
* Writes a value of an enumeration to the given output stream.
*
* @param out
* the output stream to write to
* @param enumVal
* the value of a enumeration to be written to the output stream
* @throws IOException
* thrown if any error occurred while writing data to the stream
*/
public static void writeEnum(final DataOutput out, final Enum<?> enumVal) throws IOException {
if (enumVal == null) {
out.writeBoolean(false);
} else {
out.writeBoolean(true);
StringRecord.writeString(out, enumVal.name());
}
}
}