/*
* 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 com.alibaba.jstorm.hdfs.bolt.format;
import backtype.storm.tuple.Tuple;
import java.io.Serializable;
/**
* Interface for converting <code>Tuple</code> objects to HDFS sequence file key-value pairs.
*
*/
public interface SequenceFormat extends Serializable {
/**
* Key class used by implementation (e.g. IntWritable.class, etc.)
*
* @return
*/
Class keyClass();
/**
* Value class used by implementation (e.g. Text.class, etc.)
* @return
*/
Class valueClass();
/**
* Given a tuple, return the key that should be written to the sequence file.
*
* @param tuple
* @return
*/
Object key(Tuple tuple);
/**
* Given a tuple, return the value that should be written to the sequence file.
* @param tuple
* @return
*/
Object value(Tuple tuple);
}