Github user chinmaykolhatkar commented on a diff in the pull request:
https://github.com/apache/incubator-apex-malhar/pull/219#discussion_r58043536
--- Diff:
contrib/src/main/java/com/datatorrent/contrib/parquet/ParquetFilePOJOReader.java
---
@@ -0,0 +1,318 @@
+/**
+ * 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.parquet;
+
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.StringTokenizer;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.apache.commons.lang3.ClassUtils;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+
+import com.datatorrent.api.Context;
+import com.datatorrent.api.DefaultOutputPort;
+import com.datatorrent.api.annotation.OutputPortFieldAnnotation;
+import com.datatorrent.lib.util.FieldInfo;
+import com.datatorrent.lib.util.FieldInfo.SupportType;
+import com.datatorrent.lib.util.PojoUtils;
+import com.datatorrent.lib.util.PojoUtils.Setter;
+
+import parquet.example.data.Group;
+import parquet.io.InvalidRecordException;
+import parquet.io.ParquetEncodingException;
+import parquet.schema.PrimitiveType.PrimitiveTypeName;
+
+/**
+ * <p>
+ * ParquetFilePOJOReader
+ * </p>
+ * ParquetFilePOJOReader operator is a concrete implementation of
+ * AbstractParquetFileReader to read Parquet files and emit records as
POJOs.The
+ * POJO class name & field mapping should be provided by the user. If this
+ * mapping is not provided then reflection is used to determine this
mapping. As
+ * of now only primitive types ( INT32, INT64, BOOLEAN, FLOAT, DOUBLE,
BINARY )
+ * are supported.
+ *
+ * Parquet primitive types maps to POJO datatypes as follows : INT32 -> int
+ * INT64 -> long BOOLEAN -> boolean FLOAT -> float DOUBLE -> double BINARY
->
+ * String
+ *
+ * @displayName ParquetFilePOJOReader
+ * @tags parquet,input adapter
+ * @since 3.3.0
+ */
+public class ParquetFilePOJOReader extends
AbstractParquetFileReader<Object>
+{
+
+ /**
+ * POJO class
+ */
+ protected transient Class<?> pojoClass;
+ /**
+ * Map containing setters for fields in POJO
+ */
+ protected transient Map<String, Setter> pojoSetters;
+ /**
+ * String representing Parquet TO POJO field mapping. If not provided,
then
+ * reflection is used to determine the mapping. Format :
+ * PARQUET_FIELD_NAME:POJO_FIELD_NAME:TYPE
+ * E.g.event_id:event_id_v2:INTEGER,org_id:org_id_v2:STRING,long_id:
+ * long_id_v2:
+ *
LONG,css_file_loaded:css_file_loaded_v2:BOOLEAN,float_val:float_val_v2:
+ * FLOAT,double_val:double_val_v2:DOUBLE
+ */
+ protected transient String groupToPOJOFieldsMapping = null;
+ protected transient List<FieldInfo> fieldInfos;
+ protected transient List<ActiveFieldInfo> columnFieldSetters = null;
+ protected static final String FIELD_SEPARATOR = ":";
+ protected static final String RECORD_SEPARATOR = ",";
+ private static final Logger logger =
LoggerFactory.getLogger(ParquetFilePOJOReader.class);
+
+ @OutputPortFieldAnnotation(schemaRequired = true)
+ public final transient DefaultOutputPort<Object> output = new
DefaultOutputPort<Object>()
+ {
+
+ @Override
+ public void setup(Context.PortContext context)
+ {
+ pojoClass = context.getValue(Context.PortContext.TUPLE_CLASS);
+ pojoSetters = Maps.newHashMap();
+ for (Field f : pojoClass.getDeclaredFields()) {
+ try {
+ pojoSetters.put(f.getName(), generateSettersForField(pojoClass,
f.getName()));
+ } catch (NoSuchFieldException | SecurityException e) {
+ logger.error("Failed to generate setters. Exception {}", e);
+ throw new RuntimeException(e);
+ }
+ }
+
+ if (groupToPOJOFieldsMapping == null) {
+ fieldInfos = createFieldInfoMap(generateFieldInfoInputs());
+ } else {
+ fieldInfos = createFieldInfoMap(groupToPOJOFieldsMapping);
+ }
+ initColumnFieldSetters();
+ }
+
+ };
+
+ /**
+ * Converts Group to POJO
+ */
+ @Override
+ protected Object convertGroup(Group group)
+ {
+ Object obj;
+ try {
+ obj = pojoClass.newInstance();
+ } catch (InstantiationException | IllegalAccessException ex) {
+ throw new RuntimeException(ex);
+ }
+ for (int i = 0; i < columnFieldSetters.size(); i++) {
+ try {
+ ParquetFilePOJOReader.ActiveFieldInfo afi =
columnFieldSetters.get(i);
+ int fieldIndex =
schema.getFieldIndex(afi.fieldInfo.getColumnName());
+ PrimitiveTypeName primitiveTypeName =
schema.getType(fieldIndex).asPrimitiveType().getPrimitiveTypeName();
+
+ switch (primitiveTypeName) {
+
+ case BOOLEAN:
+ Boolean booleanVal =
Boolean.parseBoolean(group.getValueToString(fieldIndex, 0));
+
pojoSetters.get(afi.fieldInfo.getPojoFieldExpression()).set(obj, booleanVal);
+ break;
+
+ case INT32:
+ Integer intVal =
Integer.parseInt(group.getValueToString(fieldIndex, 0));
+
pojoSetters.get(afi.fieldInfo.getPojoFieldExpression()).set(obj, intVal);
+ break;
+
+ case INT64:
+ Long longVal =
Long.parseLong(group.getValueToString(fieldIndex, 0));
+
pojoSetters.get(afi.fieldInfo.getPojoFieldExpression()).set(obj, longVal);
+ break;
+
+ case FLOAT:
+ Float floatVal =
Float.parseFloat(group.getValueToString(fieldIndex, 0));
+
pojoSetters.get(afi.fieldInfo.getPojoFieldExpression()).set(obj, floatVal);
+ break;
+
+ case DOUBLE:
+ Double doubleVal =
Double.parseDouble(group.getValueToString(fieldIndex, 0));
+
pojoSetters.get(afi.fieldInfo.getPojoFieldExpression()).set(obj, doubleVal);
+ break;
+
+ case BINARY:
+
pojoSetters.get(afi.fieldInfo.getPojoFieldExpression()).set(obj,
group.getValueToString(fieldIndex, 0));
+ break;
+
+ default:
+ throw new ParquetEncodingException("Unsupported column type: "
+ primitiveTypeName);
+
+ }
+ } catch (InvalidRecordException e) {
+ logger.error("Field not found in schema {} ", e);
+ }
+ }
+ return obj;
+ }
+
+ @Override
+ protected void emit(Object tuple)
+ {
+ output.emit(tuple);
+ }
+
+ /**
+ * Sets the {@link FieldInfo}s. A {@link FieldInfo} maps a store column
to a
+ * pojo field name.<br/>
+ * The value from fieldInfo.column is assigned to
+ * fieldInfo.pojoFieldExpression.
+ *
+ * @description $[].columnName name of the Output Field in POJO
+ * @description $[].pojoFieldExpression expression to get the respective
field
+ * from generic record
+ * @useSchema $[].pojoFieldExpression outputPort.fields[].name
+ */
+ public void setFieldInfos(List<FieldInfo> fieldInfos)
+ {
+ this.fieldInfos = fieldInfos;
+ }
+
+ /**
+ * Creates a map representing fieldName in POJO:field in Generic
Record:Data
+ * type
+ *
+ * @return List of FieldInfo
+ */
+ public List<FieldInfo> createFieldInfoMap(String str)
--- End diff --
Can this method be made private?
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