| package org.apache.samoa.instances; |
| |
| /* |
| * #%L |
| * SAMOA |
| * %% |
| * Copyright (C) 2014 - 2015 Apache Software Foundation |
| * %% |
| * Licensed 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. |
| * #L% |
| */ |
| |
| import java.io.BufferedReader; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.InputStreamReader; |
| import java.io.Reader; |
| |
| import org.apache.avro.Schema; |
| import org.apache.avro.generic.GenericDatumReader; |
| import org.apache.avro.generic.GenericRecord; |
| import org.apache.avro.io.Decoder; |
| import org.apache.avro.io.DecoderFactory; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public class AvroJsonLoader extends AvroLoader { |
| |
| private static final long serialVersionUID = 1L; |
| private static final Logger logger = LoggerFactory.getLogger(AvroJsonLoader.class); |
| |
| /** The Character reader for JSON read */ |
| protected Reader reader = null; |
| |
| public AvroJsonLoader(InputStream inputStream, int classAttribute) { |
| super(classAttribute); |
| initializeSchema(inputStream); |
| } |
| |
| /* (non-Javadoc) |
| * @see org.apache.samoa.instances.AvroLoader#initializeSchema(java.io.InputStream) |
| */ |
| @Override |
| public void initializeSchema(InputStream inputStream) |
| { |
| String schemaString = null; |
| try { |
| this.reader = new BufferedReader(new InputStreamReader(inputStream)); |
| schemaString = ((BufferedReader) this.reader).readLine(); |
| this.schema = new Schema.Parser().parse(schemaString); |
| this.datumReader = new GenericDatumReader<GenericRecord>(schema); |
| this.instanceInformation = getHeader(); |
| this.isSparseData = isSparseData(); |
| |
| if (classAttribute < 0) { |
| this.instanceInformation.setClassIndex(this.instanceInformation.numAttributes() - 1); |
| } else if (classAttribute > 0) { |
| this.instanceInformation.setClassIndex(classAttribute - 1); |
| } |
| |
| } catch (IOException ioException) { |
| logger.error(AVRO_LOADER_SCHEMA_READ_ERROR + " : {}", ioException); |
| throw new RuntimeException(AVRO_LOADER_SCHEMA_READ_ERROR + " : " + ioException); |
| } |
| } |
| |
| /* (non-Javadoc) |
| * @see org.apache.samoa.instances.AvroLoader#readInstance() |
| */ |
| @Override |
| public Instance readInstance() { |
| |
| String line = null; |
| Decoder decoder = null; |
| GenericRecord record = null; |
| |
| try { |
| while ((line = ((BufferedReader) reader).readLine()) != null) { |
| if (line == null || line.trim().length() <= 0) |
| continue; |
| |
| decoder = DecoderFactory.get().jsonDecoder(schema, line); |
| record = datumReader.read(null, decoder); |
| break; |
| } |
| } catch (IOException ioException) { |
| logger.error(AVRO_LOADER_INSTANCE_READ_ERROR + " : {}", ioException); |
| throw new RuntimeException(AVRO_LOADER_INSTANCE_READ_ERROR + " : " + ioException); |
| } |
| |
| if (record == null) |
| { |
| closeReader(); |
| return null; |
| } |
| |
| if (isSparseData) |
| return readInstanceSparse(record); |
| |
| return readInstanceDense(record); |
| } |
| |
| /** |
| * Close the Avro Data Stream |
| */ |
| private void closeReader() |
| { |
| if (reader != null) |
| try { |
| reader.close(); |
| } catch (IOException ioException) { |
| logger.error(AVRO_LOADER_INSTANCE_READ_ERROR + " : {}", ioException); |
| throw new RuntimeException(AVRO_LOADER_INSTANCE_READ_ERROR + " : " + ioException); |
| } |
| } |
| } |