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https://issues.apache.org/jira/browse/APEXMALHAR-2011?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15217581#comment-15217581
]
ASF GitHub Bot commented on APEXMALHAR-2011:
--------------------------------------------
Github user chinmaykolhatkar commented on a diff in the pull request:
https://github.com/apache/incubator-apex-malhar/pull/211#discussion_r57846459
--- Diff:
contrib/src/main/java/com/datatorrent/contrib/avro/PojoToAvro.java ---
@@ -0,0 +1,264 @@
+/**
+ * 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.avro;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.apache.avro.AvroRuntimeException;
+import org.apache.avro.Schema;
+import org.apache.avro.Schema.Field;
+import org.apache.avro.generic.GenericData;
+import org.apache.avro.generic.GenericRecord;
+import org.apache.commons.lang3.ClassUtils;
+import org.apache.hadoop.classification.InterfaceStability;
+
+import com.datatorrent.api.AutoMetric;
+import com.datatorrent.api.Context;
+import com.datatorrent.api.Context.PortContext;
+import com.datatorrent.api.DefaultInputPort;
+import com.datatorrent.api.DefaultOutputPort;
+import com.datatorrent.api.annotation.InputPortFieldAnnotation;
+import com.datatorrent.common.util.BaseOperator;
+import com.datatorrent.lib.util.PojoUtils;
+import com.datatorrent.lib.util.PojoUtils.Getter;
+
+/**
+ * <p>
+ * PojoToAvro
+ * </p>
+ * A generic implementation for POJO to Avro conversion. A POJO is
converted to
+ * a GenericRecord based on the schema provided. As of now only primitive
types
+ * are supported.
+ *
+ * @displayName Pojo To Avro
+ * @category Converter
+ * @tags avro
+ * @since 3.3.0
+ */
[email protected]
+public class PojoToAvro extends BaseOperator
+{
+
+ private List<Field> columnNames;
+
+ private Class<?> cls;
+
+ private List<Getter> keyMethodMap;
+
+ private transient String schemaString;
+
+ private transient Schema schema;
+
+ @AutoMetric
+ int recordCnt = 0;
+
+ @AutoMetric
+ int errorCnt = 0;
+
+ @AutoMetric
+ int fieldErrorCnt = 0;
+
+ public final transient DefaultOutputPort<GenericRecord> output = new
DefaultOutputPort<GenericRecord>();
+
+ private void parseSchema() throws IOException
+ {
+ setSchema(new Schema.Parser().parse(getSchemaString()));
+ }
+
+ /**
+ * Returns the schema string for Avro Generic Record
+ *
+ * @return schemaString
+ */
+ public String getSchemaString()
+ {
+ return schemaString;
+ }
+
+ /**
+ * Sets the schema string
+ */
+ public void setSchemaString(String schemaString)
+ {
+ this.schemaString = schemaString;
+ }
+
+ /**
+ * Returns the schema object
+ *
+ * @return schema
+ */
+ private Schema getSchema()
+ {
+ return schema;
+ }
+
+ /**
+ * Sets the shcema object
+ */
+ private void setSchema(Schema schema)
+ {
+ this.schema = schema;
+ }
+
+ /**
+ * Returns the list for field names from provided Avro schema
+ *
+ * @return List of Fields
+ */
+ private List<Field> getColumnNames()
+ {
+ return columnNames;
+ }
+
+ /**
+ * Sets the list of column names representing the fields in Avro schema
+ */
+ private void setColumnNames(List<Field> columnNames)
+ {
+ this.columnNames = columnNames;
+ }
+
+ /**
+ * This method generates the getters for provided field of a given class
+ *
+ * @return Getter
+ */
+ private Getter<?, ?> generateGettersForField(Class<?> cls, String
inputFieldName)
+ throws NoSuchFieldException, SecurityException
+ {
+ java.lang.reflect.Field f = cls.getDeclaredField(inputFieldName);
+ Class<?> c = ClassUtils.primitiveToWrapper(f.getType());
+
+ Getter<?, ?> classGetter = PojoUtils.createGetter(cls, inputFieldName,
c);
+
+ return classGetter;
+ }
+
+ /**
+ * Initializes the list of columns in POJO based on the names from schema
+ */
+ private void initializeColumnMap(Schema schema)
+ {
+ setColumnNames(schema.getFields());
+
+ keyMethodMap = new ArrayList<Getter>();
+ for (int i = 0; i < getColumnNames().size(); i++) {
+ try {
+ keyMethodMap.add(generateGettersForField(cls,
getColumnNames().get(i).name()));
+ } catch (NoSuchFieldException | SecurityException e) {
+ throw new RuntimeException("Failed to initialize pojo class
getters for field: ", e);
+ }
+ }
+ }
+
+ @InputPortFieldAnnotation(optional = false, schemaRequired = true)
+ public final transient DefaultInputPort<Object> data = new
DefaultInputPort<Object>()
+ {
+
+ @Override
+ public void setup(PortContext context)
+ {
+ cls = context.getValue(Context.PortContext.TUPLE_CLASS);
+
+ try {
+ parseSchema();
+ initializeColumnMap(getSchema());
+ } catch (IOException e) {
+ LOG.error("Exception in parsing schema -" + e.getMessage());
+ }
+ }
+
+ @Override
+ public void process(Object tuple)
+ {
+ processTuple(tuple);
+ }
+
+ };
+
+ /**
+ * Converts incoming tuples into Generic records
+ */
+ protected void processTuple(Object tuple)
+ {
+ GenericRecord record = null;
+
+ try {
+ record = getGenericRecord(tuple);
+ } catch (Exception e) {
+ LOG.error("Exception in parsing record");
+ errorCnt++;
+ }
+
+ if (record != null) {
+ output.emit(record);
+ recordCnt++;
+ } else {
+ errorCnt++;
+ }
+ }
+
+ /**
+ * Returns a generic record mapping the POJO fields to provided schema
+ *
+ * @return Generic Record
+ */
+ private GenericRecord getGenericRecord(Object tuple) throws Exception
+ {
+ int writeErrorCount = 0;
+ GenericRecord rec = new GenericData.Record(getSchema());
+
+ for (int i = 0; i < columnNames.size(); i++) {
+ try {
+ rec.put(columnNames.get(i).name(),
AvroRecordHelper.convertValueStringToAvroKeyType(getSchema(),
+ columnNames.get(i).name(),
keyMethodMap.get(i).get(tuple).toString()));
+ } catch (AvroRuntimeException e) {
+ LOG.error("Could not set Field [" + columnNames.get(i).name() + "]
in the generic record");
+ fieldErrorCnt++;
+ } catch (Exception e) {
+ LOG.error("Parse Exception");
+ fieldErrorCnt++;
+ writeErrorCount++;
+ }
+ }
+
+ if (columnNames.size() == writeErrorCount) {
+ return null;
+ } else {
+ return rec;
+ }
+ }
+
+ @Override
+ public void endWindow()
+ {
+ recordCnt = 0;
+ errorCnt = 0;
+ fieldErrorCnt = 0;
+ }
+
+ public static final Logger LOG =
LoggerFactory.getLogger(PojoToAvro.class);
--- End diff --
Should be private.
> POJO to Avro record converter
> -----------------------------
>
> Key: APEXMALHAR-2011
> URL: https://issues.apache.org/jira/browse/APEXMALHAR-2011
> Project: Apache Apex Malhar
> Issue Type: New Feature
> Reporter: devendra tagare
>
> We are looking to develop a record converter which would take a POJO as an
> input and emit a Generic record as the output based on the given Avro schema.
> The expected inputs for this operator would be,
> 1.Class Name of the incoming POJO
> 2.Avro schema for the Generic Record to emit.
> This operator would receive an Object on its input port and emit a Generic
> record on the output port.
> To start with, we would handle primitive types and then go on to handle
> complex types.
> Thanks,
> Dev
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