| /** |
| * 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 com.datatorrent.contrib.hbase; |
| |
| import java.util.List; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import org.apache.hadoop.classification.InterfaceStability.Evolving; |
| import org.apache.hadoop.hbase.Cell; |
| import org.apache.hadoop.hbase.CellUtil; |
| import org.apache.hadoop.hbase.client.Result; |
| import org.apache.hadoop.hbase.client.Scan; |
| import org.apache.hadoop.hbase.util.Bytes; |
| |
| import com.datatorrent.lib.util.FieldValueGenerator; |
| import com.datatorrent.lib.util.FieldValueGenerator.ValueConverter; |
| import com.datatorrent.lib.util.PojoUtils; |
| import com.datatorrent.lib.util.PojoUtils.Setter; |
| import com.datatorrent.lib.util.TableInfo; |
| import com.datatorrent.api.Context; |
| import com.datatorrent.api.DefaultOutputPort; |
| import com.datatorrent.api.Context.OperatorContext; |
| |
| /** |
| * HBasePOJOInputOperator reads data from a HBase store, converts it to a POJO and puts it on the output port. |
| * The read from HBase is asynchronous. |
| * @displayName HBase Input Operator |
| * @category Input |
| * @tags database, nosql, pojo, hbase |
| * @since 3.1.0 |
| */ |
| @Evolving |
| public class HBasePOJOInputOperator extends HBaseScanOperator<Object> |
| { |
| private TableInfo<HBaseFieldInfo> tableInfo; |
| private String pojoTypeName; |
| |
| // Transients |
| protected transient Class<?> pojoType; |
| protected transient FieldValueGenerator<HBaseFieldInfo> fieldValueGenerator; |
| protected transient BytesValueConverter valueConverter; |
| private transient Scan scan; |
| private transient Setter<Object, String> rowSetter; |
| |
| public static class BytesValueConverter implements ValueConverter<HBaseFieldInfo> |
| { |
| @Override |
| public Object convertValue( HBaseFieldInfo fieldInfo, Object value) |
| { |
| return fieldInfo.toValue( (byte[])value ); |
| } |
| } |
| |
| public final transient DefaultOutputPort<Object> outputPort = new DefaultOutputPort<Object>() |
| { |
| public void setup(com.datatorrent.api.Context.PortContext context) |
| { |
| pojoType = context.getAttributes().get(Context.PortContext.TUPLE_CLASS); |
| } |
| }; |
| |
| @Override |
| public void activate(Context context) |
| { |
| try { |
| pojoType.newInstance(); // try create new instance to verify the class. |
| rowSetter = PojoUtils.createSetter(pojoType, tableInfo.getRowOrIdExpression(), String.class); |
| fieldValueGenerator = new HBaseFieldValueGenerator(pojoType, tableInfo.getFieldsInfo()); |
| valueConverter = new BytesValueConverter(); |
| scan = new Scan(); |
| super.activate(context); |
| } catch (Exception ex) { |
| throw new RuntimeException(ex); |
| } |
| } |
| |
| @Override |
| protected Object getTuple(Result result) |
| { |
| try { |
| String readRow = Bytes.toString(result.getRow()); |
| if( readRow.equals( getLastReadRow() )) { |
| return null; |
| } |
| |
| Object instance = pojoType.newInstance(); |
| rowSetter.set(instance, readRow); |
| |
| List<Cell> cells = result.listCells(); |
| for (Cell cell : cells) { |
| String columnName = Bytes.toString(CellUtil.cloneQualifier(cell)); |
| String columnFamily = Bytes.toString(CellUtil.cloneFamily(cell)); |
| byte[] value = CellUtil.cloneValue(cell); |
| ((HBaseFieldValueGenerator)fieldValueGenerator).setColumnValue(instance, columnName, columnFamily, value, |
| valueConverter); |
| } |
| |
| setLastReadRow(readRow); |
| return instance; |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| @Override |
| protected Scan operationScan() |
| { |
| if (getLastReadRow() == null && getStartRow() == null) { |
| // If no start row specified and no row read yet |
| if (scan == null) { |
| scan = new Scan(); |
| } |
| } else if (getEndRow() == null) { |
| // If only start row specified |
| scan.setStartRow(Bytes.toBytes(getLastReadRow() == null ? getStartRow() : getLastReadRow())); |
| } else { |
| // If end row also specified |
| scan.setStartRow(Bytes.toBytes(getLastReadRow() == null ? getStartRow() : getLastReadRow())); |
| scan.setStopRow(Bytes.toBytes(getEndRow())); |
| } |
| for (HBaseFieldInfo field : tableInfo.getFieldsInfo()) { |
| scan.addColumn(Bytes.toBytes(field.getFamilyName()), Bytes.toBytes(field.getColumnName())); |
| } |
| return scan; |
| } |
| |
| @Override |
| protected void emitTuple(Object tuple) |
| { |
| outputPort.emit(tuple); |
| } |
| |
| /** |
| * Returns the {@link #tableInfo} object as configured |
| * @return {@link #tableInfo} |
| */ |
| public TableInfo<HBaseFieldInfo> getTableInfo() |
| { |
| return tableInfo; |
| } |
| |
| /** |
| * Sets the {@link #tableInfo} object |
| * @param tableInfo |
| */ |
| public void setTableInfo(TableInfo<HBaseFieldInfo> tableInfo) |
| { |
| this.tableInfo = tableInfo; |
| } |
| |
| /** |
| * Returns the POJO class name |
| * @return {@link #pojoTypeName} |
| */ |
| public String getPojoTypeName() |
| { |
| return pojoTypeName; |
| } |
| |
| /** |
| * Sets the POJO class name |
| * @param pojoTypeName |
| */ |
| public void setPojoTypeName(String pojoTypeName) |
| { |
| this.pojoTypeName = pojoTypeName; |
| } |
| |
| private static final Logger logger = LoggerFactory.getLogger(HBasePOJOInputOperator.class); |
| |
| } |