A custom data transform implementation can be achieved by implementing the matcher and converter interfaces as shown in the example below.

Consider a scenario where you want to mask a sensitive field's value during replicat process.

1. Configure the target column which matches the following criteria:
   1. Catalog name: Cat1
   2. Schema name: Sch1
   3. Table name: Sample_Table
   4. Column name: Sample_Column
2. Configure a converter with some conversion implementation.
   1. Replace the column values for the above matched column with a masked value

@Matcher(id = "matcher1", description = "Custom target column matcher.")
public class CustomTargetMatcher implements TargetMatcher {
    @Override
    public boolean matches(final TableMetaData tableMetaData) {
        return tableMetaData.getCatalogName().equals("Cat1") && tableMetaData.getSchemaName().equals("Sch1") && tableMetaData.getTableName().equals("Sample_Table");
    }
    @Override
    public boolean matches(final ColumnMetaData columnMetaData) {
                return columnMetaData.getColumnName().equals("Sample_Column");
    }
}

@Converter(id = "converter1", description = "Custom data converter.")
public class CustomConverter implements DataConverter {
    
    public String convert(String originalData, final TableMetaData tableMetaData, final ColumnMetaData columnMetaData) {
         return "********"; // Masked Value
    }
}

Adapter properties for this implementation

gg.transforms=t1

# This config corresponds to the @Matcher => id param
gg.transform.t1.matcher=matcher1
# This config corresponds to the @Converter => id param
gg.transform.t1.converter=converter1

To use the custom classes:

Place the custom classes into a JAR and include them in the classpath. Include the custom JAR files in the JVM classpath using the Java properties (using java.class.path in the jvm.bootoptions property) or under gg.classpath