org.apache.parquet.hadoop.example.GroupReadSupport Maven / Gradle / Ivy
/*
* 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.parquet.hadoop.example;
import java.util.Map;
import org.apache.hadoop.conf.Configuration;
import org.apache.parquet.example.data.Group;
import org.apache.parquet.example.data.simple.convert.GroupRecordConverter;
import org.apache.parquet.hadoop.api.ReadSupport;
import org.apache.parquet.io.api.RecordMaterializer;
import org.apache.parquet.schema.MessageType;
public class GroupReadSupport extends ReadSupport {
@Override
public org.apache.parquet.hadoop.api.ReadSupport.ReadContext init(
Configuration configuration, Map keyValueMetaData,
MessageType fileSchema) {
String partialSchemaString = configuration.get(ReadSupport.PARQUET_READ_SCHEMA);
MessageType requestedProjection = getSchemaForRead(fileSchema, partialSchemaString);
return new ReadContext(requestedProjection);
}
@Override
public RecordMaterializer prepareForRead(Configuration configuration,
Map keyValueMetaData, MessageType fileSchema,
org.apache.parquet.hadoop.api.ReadSupport.ReadContext readContext) {
return new GroupRecordConverter(readContext.getRequestedSchema());
}
}