Interface for custom field types 

The CustomFieldType interface marks Solr custom field types and provides their actual stored field type.

DataStax Enterprise implements a CustomFieldType interface that marks Solr custom field types and provides their actual stored field type. The custom field type stores an integer trie field as a string representing a comma separated list of integer values: when indexed, the string is split into its integer values, each one indexed as a trie integer field. This class effectively implements a multi-valued field based on its string representation.

To use the CustomFieldType interface:
  1. Implement a custom field type class something like the following reference implementation.
  2. Export the class to a JAR, and place the JAR in this location:
    • Package installations: usr/share/dse
    • Installer-No Services and Tarball installations: install_location/resources/dse/lib

The JAR is added to the CLASSPATH automatically.

Reference implementation

Here is an example of a custom field type class:

package com.datastax.bdp.search.solr.functional;

import com.datastax.bdp.search.solr.CustomFieldType;
import java.util.ArrayList;
import java.util.List;
import org.apache.lucene.index.IndexableField;
import org.apache.solr.schema.FieldType;
import org.apache.solr.schema.SchemaField;
import org.apache.solr.schema.StrField;
import org.apache.solr.schema.TrieField;

public class CustomTestField extends TrieField implements CustomFieldType
{
    public CustomTestField()
    {
        this.type = TrieField.TrieTypes.INTEGER;
    }

    @Override
    public FieldType getStoredFieldType()
    {
        return new StrField();
    }

    @Override
    public boolean multiValuedFieldCache()
    {
        return true;
    }

    @Override
    public List<IndexableField> createFields(SchemaField sf, Object value, float boost)
    {
        String[] values = ((String) value).split(" ");
        List<IndexableField> fields = new ArrayList<IndexableField>();
        for (String v : values)
        {
            fields.add(createField(sf, v, boost));
        }
        return fields;
    }

    @Override
    public String toInternal(String value)
    {
        return value;
    }

    @Override
    public String toExternal(IndexableField f)
    {
        return f.stringValue();
    }
}