org.elasticsearch.hadoop.mr.WritableCompatUtil Maven / Gradle / Ivy
/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.hadoop.mr;
import java.lang.reflect.Constructor;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Writable;
import org.elasticsearch.hadoop.EsHadoopIllegalStateException;
/**
* Utility handling the difference in built-in Writable between Hadoop 1 and 2.
*/
@SuppressWarnings("unchecked")
public abstract class WritableCompatUtil {
private final static Class SHORT_WRITABLE;
private final static Constructor SHORT_CTOR;
static {
Class clazz = null;
Constructor ctor = null;
try {
clazz = (Class) Class.forName("org.apache.hadoop.io.ShortWritable", false, IntWritable.class.getClassLoader());
ctor = clazz.getConstructor(short.class);
} catch (Exception ex) {
}
SHORT_WRITABLE = clazz;
SHORT_CTOR = ctor;
}
public static Class availableShortType() {
return (SHORT_WRITABLE != null ? SHORT_WRITABLE : IntWritable.class);
}
public static Writable availableShortWritable(short value) {
if (SHORT_CTOR != null) {
try {
return SHORT_CTOR.newInstance(value);
} catch (Exception e) {
throw new EsHadoopIllegalStateException(e);
}
}
return new IntWritable(value);
}
public static short unwrap(Writable writable) {
return Short.parseShort(writable.toString());
}
public static boolean isShortWritable(Writable writable) {
return (SHORT_WRITABLE != null && writable != null && SHORT_WRITABLE.isInstance(writable));
}
}