User Defined Function/Operation Assembly () processes data using Java-based functions defined by the user.
This assembly processes one input record at a time and can emit zero, one, or multiple output records.

It is typically used when built-in transformation functions are not sufficient and custom processing logic is required.

Parameters of User Defined Function / Operation

• UDF Function-class
  Java class that extends com.solusi247.function.Function247
• Parameter
  Parameter value passed to the UDF class
• Output Fields
  List of output field names and their data types

Creating a User Defined Function / Operation

A User Defined Function / Operation is created by:

1. Creating a Java class that extends com.solusi247.function.Function247
2. Implementing the following abstract method:

       void operate(List<Comparable> record)
   

   This method is executed once for every input record.

Methods of com.solusi247.function.Function247

The class com.solusi247.function.Function247 provides the following methods:

1. public abstract void operate(List<Comparable> record)
   Called for every incoming record.
   Contains the core processing logic.
2. public String getParameter()
   this method returns the received parameter
3. public void prepare()
   Called after the UDF object is created.
   Used for initialization logic.
4. public void cleanup()
   Called after all records have been processed.
   Used for cleanup or resource release.
5. public final void addToOutputCollector(List<Comparable> record)
   Emits a record to the output stream.
6. public List<String> getIncomingFields()
   Returns the list of field names from the incoming record.

Example: Java-Based User Defined Function / Operation

Reverse a Specific Field in a Record

package plugins.function;

import com.solusi247.function.Function247;
import java.util.ArrayList;
import java.util.List;


public class Reverse extends Function247{

    @Override
    public void operate(List<Comparable> record) {
        
        ArrayList<Comparable> list_out=new ArrayList<>();
        for (int i=0; i<list.size(); i++){
            if (i==5){
                StringBuilder sb=new StringBuilder(record.get(i).toString());
                list_out.add(sb.reverse().toString());
            }else{
                list_out.add(list.get(i));
            }
        }        
        this.addToOutputCollector(list_out);
        
    }
    
}

Explanation of the Example

• The input record is received as List<Comparable>
• The field at index 5 is reversed
• All other fields remain unchanged
• The transformed record is emitted using addToOutputCollector()

Deploying the UDF in HGrid247

To make the UDF appear in the HGrid247-3.5 GUI:

• Compile the Java class into a JAR file
• Place the JAR file into the following directory:

      HGrid247-3.5/
      ├── plugins/
      │     └── Reverse.jar
  

• Restart the HGrid247 GUI
• The UDF will be available in User Defined Function / Operation Assembly

Required Dependency

Java-based plug-ins require the following library:

    libCommon/HGrid247CommonLib-3.5.jar

Summary

The User Defined Function / Operation Assembly enables developers to:

• Implement advanced or proprietary logic
• Process records programmatically using Java
• Extend the platform beyond built-in assembly

This assembly provides maximum flexibility and is ideal for complex data processing requirements.

Supported Engines

Map Reduce	Spark 1.x RDD	Spark 2.x RDD	Spark 2.x Dataset	Apache Beam 2.29.0 Batch	Apache Beam 2.29.0 Streaming	Apache Flink 1.12.0 Batch	Apache Flink 1.12.0 Streaming	Apache Tez 0.9.1	PySpark