| /** |
| * 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 example; |
| |
| import java.io.File; |
| import java.io.IOException; |
| |
| import org.apache.avro.file.DataFileReader; |
| import org.apache.avro.file.DataFileWriter; |
| import org.apache.avro.io.DatumReader; |
| import org.apache.avro.io.DatumWriter; |
| import org.apache.avro.specific.SpecificDatumReader; |
| import org.apache.avro.specific.SpecificDatumWriter; |
| |
| import example.avro.User; |
| |
| public class SpecificMain { |
| public static void main(String[] args) throws IOException { |
| User user1 = new User(); |
| user1.setName("Alyssa"); |
| user1.setFavoriteNumber(256); |
| // Leave favorite color null |
| |
| // Alternate constructor |
| User user2 = new User("Ben", 7, "red"); |
| |
| // Construct via builder |
| User user3 = User.newBuilder() |
| .setName("Charlie") |
| .setFavoriteColor("blue") |
| .setFavoriteNumber(null) |
| .build(); |
| |
| // Serialize user1 and user2 to disk |
| File file = new File("users.avro"); |
| DatumWriter<User> userDatumWriter = new SpecificDatumWriter<User>(User.class); |
| DataFileWriter<User> dataFileWriter = new DataFileWriter<User>(userDatumWriter); |
| dataFileWriter.create(user1.getSchema(), file); |
| dataFileWriter.append(user1); |
| dataFileWriter.append(user2); |
| dataFileWriter.append(user3); |
| dataFileWriter.close(); |
| |
| // Deserialize Users from disk |
| DatumReader<User> userDatumReader = new SpecificDatumReader<User>(User.class); |
| DataFileReader<User> dataFileReader = new DataFileReader<User>(file, userDatumReader); |
| User user = null; |
| while (dataFileReader.hasNext()) { |
| // Reuse user object by passing it to next(). This saves us from |
| // allocating and garbage collecting many objects for files with |
| // many items. |
| user = dataFileReader.next(user); |
| System.out.println(user); |
| } |
| |
| } |
| } |