非Hibernate环境下如何将List<String>存入PostgreSQL的JSONB字段？

Since you're using Spring Data Reactive (R2DBC) without Hibernate, the @Type annotation won't work here. The error occurs because R2DBC doesn't automatically know how to convert a List<String> to PostgreSQL's jsonb type—it's defaulting to treating it as a primitive array (hence the smallint[] mismatch). Here's how to fix this:

Step 1: Create Custom Converters #

You need two converters: one to serialize your List<String> to a JSON object, and another to deserialize the JSON back to a List<String>. We'll use Jackson's ObjectMapper for this (most Spring Boot projects include this by default, but add it to your dependencies if missing).

List to Json Converter #

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.core.convert.converter.Converter;
import org.springframework.data.convert.WritingConverter;
import io.r2dbc.postgresql.codec.Json;

import java.util.List;

@WritingConverter
public class ListToJsonConverter implements Converter<List<String>, Json> {

    private final ObjectMapper objectMapper;

    public ListToJsonConverter(ObjectMapper objectMapper) {
        this.objectMapper = objectMapper;
    }

    @Override
    public Json convert(List<String> source) {
        try {
            return Json.of(objectMapper.writeValueAsString(source));
        } catch (JsonProcessingException e) {
            throw new IllegalArgumentException("Failed to convert List<String> to JSON", e);
        }
    }
}

Json to List Converter #

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.core.convert.converter.Converter;
import org.springframework.data.convert.ReadingConverter;
import io.r2dbc.postgresql.codec.Json;

import java.util.List;

@ReadingConverter
public class JsonToListConverter implements Converter<Json, List<String>> {

    private final ObjectMapper objectMapper;

    public JsonToListConverter(ObjectMapper objectMapper) {
        this.objectMapper = objectMapper;
    }

    @Override
    public List<String> convert(Json source) {
        try {
            return objectMapper.readValue(source.asString(), new TypeReference<List<String>>() {});
        } catch (Exception e) {
            throw new IllegalArgumentException("Failed to convert JSON to List<String>", e);
        }
    }
}

Step 2: Register the Converters #

Register your custom converters with the R2DBC configuration. Create a configuration class to handle this:

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.r2dbc.config.AbstractR2dbcConfiguration;
import org.springframework.data.r2dbc.convert.R2dbcCustomConversions;
import io.r2dbc.spi.ConnectionFactory;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.Arrays;

@Configuration
public class R2dbcConfig extends AbstractR2dbcConfiguration {

    private final ObjectMapper objectMapper;

    public R2dbcConfig(ObjectMapper objectMapper) {
        this.objectMapper = objectMapper;
    }

    @Override
    public ConnectionFactory connectionFactory() {
        // Add your existing PostgreSQL ConnectionFactory setup here
        // Example: return new PostgresConnectionFactory(PostgresConnectionConfiguration.builder()...build());
    }

    @Override
    protected R2dbcCustomConversions r2dbcCustomConversions() {
        return new R2dbcCustomConversions(
            R2dbcCustomConversions.STORE_CONVERTERS,
            Arrays.asList(
                new ListToJsonConverter(objectMapper),
                new JsonToListConverter(objectMapper)
            )
        );
    }
}

If you don't want to extend AbstractR2dbcConfiguration, you can register the conversions as a standalone bean:

@Bean
public R2dbcCustomConversions r2dbcCustomConversions(ObjectMapper objectMapper) {
    return new R2dbcCustomConversions(
        R2dbcCustomConversions.STORE_CONVERTERS,
        Arrays.asList(
            new ListToJsonConverter(objectMapper),
            new JsonToListConverter(objectMapper)
        )
    );
}

Step 3: Explicitly Define Column Type (Optional) #

To make your entity class clearer, explicitly specify the column type for the colors field:

public class Tool implements Persistable<UUID> {
    @Id
    @Column("tool_id")
    private UUID id;
    @Column("tool_name")
    private String name;
    @Column(value = "tool_colors", columnDefinition = "jsonb")
    private List<String> colors;

    // Add getters, setters, and Persistable interface implementations here
}

Step 4: Test the Setup #

Now when you call toolRepository.save(tool), R2DBC will use your custom converters to serialize the List<String> to a JSONB-compatible value, resolving the type mismatch error.

内容的提问来源于stack exchange，提问作者lgean