jpa list converter

JPA (Java Persistence API) provides a way to convert collections of non-standard types to and from the database. To convert a list of objects to a database column, you can create a custom converter using the `@Converter` annotation.

Here's an example of how you can create a converter for a list of strings:

import javax.persistence.AttributeConverter;
import javax.persistence.Converter;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

@Converter
public class ListConverter implements AttributeConverter<List<String>, String> {

    private static final String DELIMITER = ",";