Java tutorial
/* * 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.gobblin.converter.objectstore; import org.apache.avro.Schema; import org.apache.avro.generic.GenericRecord; import org.apache.avro.util.Utf8; import com.google.common.annotations.VisibleForTesting; import com.google.common.base.Charsets; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import com.google.common.primitives.Ints; import com.google.common.primitives.Longs; import org.apache.gobblin.annotation.Alpha; import org.apache.gobblin.configuration.WorkUnitState; import org.apache.gobblin.converter.DataConversionException; import org.apache.gobblin.converter.SingleRecordIterable; import org.apache.gobblin.util.AvroUtils; import org.apache.gobblin.writer.objectstore.ObjectStoreDeleteOperation; import org.apache.gobblin.writer.objectstore.ObjectStoreOperationBuilder; /** * A converter to build {@link ObjectStoreDeleteOperation}s using an Avro {@link GenericRecord}. The object id field in * input avro record can be set using {@link #OBJECT_ID_FIELD}. The field name is a required property. * * Supports objectIdField schema types string, int, long and bytes. * */ @Alpha public class ObjectStoreDeleteConverter extends ObjectStoreConverter<Schema, GenericRecord, ObjectStoreDeleteOperation> { @VisibleForTesting public static final String OBJECT_ID_FIELD = "gobblin.converter.objectstore.delete.objectIdField"; private String objectIdField; @Override public ObjectStoreDeleteConverter init(WorkUnitState workUnit) { Preconditions.checkArgument(workUnit.contains(OBJECT_ID_FIELD), String.format("%s is a required property. ", OBJECT_ID_FIELD)); this.objectIdField = workUnit.getProp(OBJECT_ID_FIELD); return this; } @Override public Iterable<ObjectStoreDeleteOperation> convertRecord(Class<?> outputSchema, GenericRecord inputRecord, WorkUnitState workUnit) throws DataConversionException { Optional<Object> fieldValue = AvroUtils.getFieldValue(inputRecord, this.objectIdField); byte[] objectId; if (fieldValue.isPresent()) { if (fieldValue.get() instanceof Utf8) { objectId = ((Utf8) fieldValue.get()).getBytes(); } else if (fieldValue.get() instanceof String) { objectId = ((String) fieldValue.get()).getBytes(Charsets.UTF_8); } else if (fieldValue.get() instanceof Long) { objectId = Longs.toByteArray((Long) fieldValue.get()); } else if (fieldValue.get() instanceof Integer) { objectId = Ints.toByteArray((Integer) fieldValue.get()); } else { objectId = (byte[]) fieldValue.get(); } return new SingleRecordIterable<ObjectStoreDeleteOperation>( ObjectStoreOperationBuilder.deleteBuilder().withObjectId(objectId).build()); } else { throw new DataConversionException( String.format("Object Id field %s not found in record %s", this.objectIdField, inputRecord)); } } }