/*
* 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.nifi.processors.parquet.record;
import org.apache.avro.generic.GenericRecord;
import org.apache.nifi.avro.AvroTypeUtil;
import org.apache.nifi.processors.hadoop.record.HDFSRecordReader;
import org.apache.nifi.serialization.record.MapRecord;
import org.apache.nifi.serialization.record.Record;
import org.apache.nifi.serialization.record.RecordSchema;
import org.apache.parquet.hadoop.ParquetReader;
import java.io.IOException;
import java.util.Map;
/**
* HDFSRecordReader that reads Parquet files using Avro.
*/
public class AvroParquetHDFSRecordReader implements HDFSRecordReader {
private GenericRecord lastRecord;
private RecordSchema recordSchema;
private boolean initialized = false;
private final ParquetReader<GenericRecord> parquetReader;
public AvroParquetHDFSRecordReader(final ParquetReader<GenericRecord> parquetReader) {
this.parquetReader = parquetReader;
}
@Override
public Record nextRecord() throws IOException {
if (initialized && lastRecord == null) {
return null;
}
lastRecord = parquetReader.read();
initialized = true;
if (lastRecord == null) {
return null;
}
if (recordSchema == null) {
recordSchema = AvroTypeUtil.createSchema(lastRecord.getSchema());
}
final Map<String, Object> values = AvroTypeUtil.convertAvroRecordToMap(lastRecord, recordSchema);
return new MapRecord(recordSchema, values);
}
@Override
public void close() throws IOException {
parquetReader.close();
}
}