java - 使用JDBI将2d数组插入PostreSQL DB？

我可以使用SQL对象API将Game映射到GAMES数据库中的一行吗？以下是我的尝试：
数据类：

public class Game {
    protected int id;
    protected int whoseTurn;
    protected int winner;
    protected char[][] board;

    public Game(int id, int turn, int winner, char[][] board ) {
        this.id=id;
        this.whoseTurn=turn;
        this.winner=winner;
        this.board=board;
    }

    @JsonProperty
    public int getId() {
        return id;
    }

    @JsonInclude(Include.NON_NULL)
    public int getWhoseTurn() {
        return whoseTurn;
    }

    @JsonInclude(Include.NON_NULL)
    public int getWinner() {
        return winner;
    }

    public char[][] getBoard() {
        return board;
    }
}

道：

@RegisterMapper(GameMapper.class)
public interface GameDAO {

    @SqlUpdate("create table if not exists GAMES (ID integer, WHOSE_TURN varchar(10), WINNER varchar(10), BOARD char(1)[][])")
    void createTableIfNotExists();

    @SqlUpdate("insert into GAMES (ID, WHOSE_TURN, WINNER, BOARD) values (:id, :whoseTurn, :winner, :board)")
    void insert(@BindBean Game game);
}

当调用insert时，我得到以下错误：

org.postgresql.util.PSQLException: Can't infer the SQL type to use for an instance of [[C. Use setObject() with an explicit Types value to specify the type to use.

什么是[[C？我能让这个工作吗？如果不是的话，我真的很感激你的选择。

最佳答案

JDBI不知道如何转换数组类型。所以我们需要像这样为char[][]定义ArgumentFactory。

import org.skife.jdbi.v2.StatementContext;
import org.skife.jdbi.v2.tweak.Argument;
import org.skife.jdbi.v2.tweak.ArgumentFactory;

import java.sql.Array;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class CharArrayArgument implements ArgumentFactory<char[][]> {
    @Override
    public boolean accepts(Class<?> expectedType, Object value, StatementContext ctx) {
        return value != null && char[][].class.isAssignableFrom(value.getClass());
    }

    @Override
    public Argument build(Class<?> expectedType, final char[][] value, StatementContext ctx) {
        return new Argument() {
            @Override
            public void apply(int position, PreparedStatement statement, StatementContext ctx) throws SQLException {
                Array values = statement.getConnection().createArrayOf("char", value);
                statement.setArray(position, values);
            }
        };
    }
}

将此argumentFactory注册到dbi。它应该有用。

    dbi.registerArgumentFactory(new CharArrayArgument());
    GameDao gameDao = dbi.open(GameDao.class);
    Game game = new Game(1, 2, 3, new char[][]{{'a'}, {'b'}});

    gameDao.createTableIfNotExists();
    gameDao.insert(game);