com.ebay.nest.io.sede.NullStructSerDe.java Source code

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Here is the source code for com.ebay.nest.io.sede.NullStructSerDe.java

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/**
 * 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.ebay.nest.io.sede;

import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Writable;

import com.ebay.nest.io.sede.objectinspector.ObjectInspector;
import com.ebay.nest.io.sede.objectinspector.StructField;
import com.ebay.nest.io.sede.objectinspector.StructObjectInspector;

/**
 * Placeholder SerDe for cases where neither serialization nor deserialization is needed
 *
 */
public class NullStructSerDe extends AbstractSerDe {

    class NullStructField implements StructField {
        @Override
        public String getFieldName() {
            return null;
        }

        @Override
        public ObjectInspector getFieldObjectInspector() {
            return null;
        }

        @Override
        public String getFieldComment() {
            return "";
        }
    }

    @Override
    public Object deserialize(Writable blob) throws SerDeException {
        return null;
    }

    private static ObjectInspector nullStructOI = new NullStructSerDeObjectInspector();

    @Override
    public ObjectInspector getObjectInspector() throws SerDeException {
        return nullStructOI;
    }

    @Override
    public SerDeStats getSerDeStats() {
        return null;
    }

    @Override
    public void initialize(Configuration conf, Properties tbl) throws SerDeException {
    }

    @Override
    public Class<? extends Writable> getSerializedClass() {
        return NullWritable.class;
    }

    @Override
    public Writable serialize(Object obj, ObjectInspector objInspector) throws SerDeException {
        return NullWritable.get();
    }

    /**
     * A object inspector for null struct serde.
     */
    public static class NullStructSerDeObjectInspector extends StructObjectInspector {
        public String getTypeName() {
            return "null";
        }

        public Category getCategory() {
            return Category.PRIMITIVE;
        }

        @Override
        public StructField getStructFieldRef(String fieldName) {
            return null;
        }

        @Override
        public List<NullStructField> getAllStructFieldRefs() {
            return new ArrayList<NullStructField>();
        }

        @Override
        public Object getStructFieldData(Object data, StructField fieldRef) {
            return null;
        }

        @Override
        public List<Object> getStructFieldsDataAsList(Object data) {
            return new ArrayList<Object>();
        }
    }

}