aswi2022code-of-duty-gitlab/backend/src/main/java/cz/zcu/kiv/backendapi/external/SetToStringConverter.java @ e21b7441

package cz.zcu.kiv.backendapi.external;

import javax.persistence.AttributeConverter;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * Class that converts set of strings to string and string to set of strings
 */
public class SetToStringConverter implements AttributeConverter<Set<String>, String> {
    /**
     * Delimiter for splitting/joining string
     */
    private static final String DELIMITER = ",";

    @Override
    public String convertToDatabaseColumn(Set<String> attribute) {
        return attribute == null ? null : String.join(DELIMITER, attribute);
    }

    @Override
    public Set<String> convertToEntityAttribute(String dbData) {
        return dbData == null ? new HashSet<>() : Arrays.stream(dbData.split(DELIMITER)).collect(Collectors.toSet());
    }

}