content: /**
   * 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.apex.malhar.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.apex.malhar.lib.util.PojoUtils;
  import org.apache.apex.malhar.lib.util.PojoUtils.Getter;
  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.google.common.annotations.VisibleForTesting;
  
  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;
  
  /**
   * <p>
   * PojoToAvro
   * </p>
   * A generic implementation for POJO to Avro conversion. A POJO is converted to
   * a GenericRecord based on the schema provided.<br>
   * As of now only primitive types are supported.<br>
   * Error records are emitted on the errorPort if connected
   *
   * @displayName Pojo To Avro
   * @category Converter
   * @tags avro
   *
   * @since 3.4.0
   */
  @InterfaceStability.Evolving
  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
    @VisibleForTesting
    int recordCount = 0;
  
    @AutoMetric
    @VisibleForTesting
    int errorCount = 0;
  
    @AutoMetric
    @VisibleForTesting
    int fieldErrorCount = 0;
  
    public final transient DefaultOutputPort<GenericRecord> output = new DefaultOutputPort<>();
  
    public final transient DefaultOutputPort<Object> errorPort = new DefaultOutputPort<>();
  
    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<>();
      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(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);
        }
      }
  
      @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 creating record");
        errorCount++;
      }
  
      if (record != null) {
        output.emit(record);
        recordCount++;
      } else if (errorPort.isConnected()) {
        errorPort.emit(tuple);
        errorCount++;
      }
    }
  
    /**
     * 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", e);
          fieldErrorCount++;
        } catch (Exception e) {
          LOG.error("Parse Exception", e);
          fieldErrorCount++;
          writeErrorCount++;
        }
      }
  
      if (columnNames.size() == writeErrorCount) {
        errorCount++;
        return null;
      } else {
        return rec;
      }
    }
  
    @Override
    public void beginWindow(long windowId)
    {
      recordCount = 0;
      errorCount = 0;
      fieldErrorCount = 0;
    }
  
    private static final Logger LOG = LoggerFactory.getLogger(PojoToAvro.class);
  
  }
  