How to map an ArrayList of primitives to a single column?

Question

Let\'s say I have the following situation:

Object Car has an ArrayList of prices, which are all numbers. Is it possible in Hibernate to save all the prices in a sin

Answer 1

I know this is an old question but for anyone trying to do this in a JPA context you can do this

import org.apache.commons.lang3.StringUtils;
import javax.persistence.AttributeConverter;
import javax.persistence.Converter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.util.Collections;

@Converter
public class IntArrayToStringConverter implements AttributeConverter,String>{
    @Override
    public String convertToDatabaseColumn(List attribute) {
        return attribute == null ? null : StringUtils.join(attribute,",");
    }

    @Override
    public List convertToEntityAttribute(String dbData) {
        if (StringUtils.isBlank(dbData))
            return Collections.emptyList();

        try (Stream stream = Arrays.stream(dbData.split(","))) {
            return stream.map(Integer::parseInt).collect(Collectors.toList());
        }
    }
}

Then to use it something like this in your entity

@Entity
public class SomeEntity
{

   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   private Integer id;

   @Column
   @Convert(converter = IntArrayToStringConverter.class)
   private List integers;

   ...
}