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https://issues.apache.org/jira/browse/APEXMALHAR-2011?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15197040#comment-15197040
]
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_r56298968
--- Diff:
contrib/src/main/java/com/datatorrent/contrib/avro/PojoToAvro.java ---
@@ -0,0 +1,296 @@
+/**
+ * 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.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
+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.OperatorContext;
+import com.datatorrent.api.Context.PortContext;
+import com.datatorrent.api.DefaultInputPort;
+import com.datatorrent.api.DefaultOutputPort;
+import com.datatorrent.api.Operator;
+import com.datatorrent.api.annotation.InputPortFieldAnnotation;
+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 implements Operator
+{
+
+ private List<Field> columnNames;
+
+ private Class<?> cls;
+
+ private List<Getter> keyMethodMap;
+
+ private String schemaFile;
+
+ private Schema schema;
+
+ @AutoMetric
+ int recordCnt = 0;
+
+ @AutoMetric
+ int errorCnt = 0;
+
+ @AutoMetric
+ int fieldErrorCnt = 0;
+
+ public final transient DefaultOutputPort<GenericRecord> output = new
DefaultOutputPort<GenericRecord>();
+
+ @Override
+ public void setup(OperatorContext context)
+ {
+ try {
+ parseSchema();
+ } catch (IOException e) {
+ LOG.error("Exception in parsing schema");
+ }
+ initializeColumnMap(getSchema());
+ }
+
+ public void parseSchema() throws IOException
+ {
+ setSchema(new Schema.Parser().parse(getSchemaString()));
+ }
+
+ public String getSchemaString()
+ {
+ return schemaFile;
+ }
+
+ public void setSchemaString(String schemaFile)
+ {
+ this.schemaFile = schemaFile;
+ }
+
+ public Schema getSchema()
+ {
+ return schema;
+ }
+
+ public void setSchema(Schema schema)
+ {
+ this.schema = schema;
+ }
+
+ public List<Field> getColumnNames()
+ {
+ return columnNames;
+ }
+
+ public void setColumnNames(List<Field> columnNames)
+ {
+ this.columnNames = columnNames;
+ }
+
+ public Class<?> getCls()
+ {
+ return cls;
+ }
+
+ public void setCls(Class<?> cls)
+ {
+ this.cls = cls;
+ }
+
+ public List<Getter> getKeyMethodMap()
+ {
+ return keyMethodMap;
+ }
+
+ public void setKeyMethodMap(List<Getter> keyMethodMap)
+ {
+ this.keyMethodMap = keyMethodMap;
+ }
+
+ /**
+ * Adding this as a plug for being able to serialize non primitive types
+ *
+ * @param -
+ * object to serialize Returns a byte array
+ */
+
+ public byte[] serialize(Object obj) throws IOException
+ {
+ try (ByteArrayOutputStream b = new ByteArrayOutputStream()) {
+ try (ObjectOutputStream o = new ObjectOutputStream(b)) {
+ o.writeObject(obj);
+ }
+ return b.toByteArray();
+ }
+ }
+
+ /**
+ * @param -
+ * className
+ * @param -
+ * name of the field to create the getter for Returns a 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;
+ }
+
+ /**
+ * @param -
+ * schema of the generic record Assumption is that the name of a
+ * field in POJO is the same as the name in Avro schema
+ */
+
+ public void initializeColumnMap(Schema schema)
+ {
+ columnNames = schema.getFields();
+
+ keyMethodMap = new ArrayList<Getter>();
+ for (int i = 0; i < columnNames.size(); i++) {
+ try {
+ keyMethodMap.add(generateGettersForField(cls,
columnNames.get(i).name()));
+ } catch (NoSuchFieldException | SecurityException e) {
+ throw new RuntimeException("Failed to initialize pojo class
getters for field: ", e);
+ }
+ }
+ }
+
+ @InputPortFieldAnnotation(optional = true, schemaRequired = true)
+ public final transient DefaultInputPort<Object> data = new
DefaultInputPort<Object>()
+ {
+
+ @Override
+ public void setup(PortContext context)
+ {
+ cls = context.getValue(Context.PortContext.TUPLE_CLASS);
+ }
+
+ @Override
+ public void process(Object tuple)
+ {
+
+ GenericRecord record = null;
--- End diff --
Please create a protected process method at operator class level and call
that method from this process method.
This is to ensure that one can extend processing of tuple.
> 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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