Question

文档显示，我不能将Jdbi与Dao Interface一起使用，请参见http://jdbi.org/#_reflection_mappers 它会引发下一个异常：

Exception in thread "main" java.lang.IllegalArgumentException: A bean, model.tipolog.TipoLog, was mapped which was not instantiable

List<TipoLog> tipoLogs1=jdbi.withExtension(TipoLogDao.class,dao->{
        return dao.listAllLogs();
});

public interface TipoLogDao {
    @SqlQuery("SELECT * FROM tamble")
    @RegisterBeanMapper(TipoLog.class)
    List<TipoLog> listAllLogs();
}

public class TipoLog {

    private String IdTipoLog;
    private String Nombre;
    private String Descripcion;
    private String Activo;

    @ConstructorProperties({"IdTipoLog", "Nombre", "Descripcion", "Activo"})
    public TipoLog(String IdTipoLog, String Nombre, String Descripcion, String Activo) {
        this.IdTipoLog = IdTipoLog;
        this.Nombre = Nombre;
        this.Descripcion = Descripcion;
        this.Activo = Activo;
    }
}

Answer 1

您不需要默认的构造函数。使用@RegisterConstructorMapper而不是@RegisterBeanMapper。

Answer 2

您的TipoLog类需要默认构造函数。这有效：

User.java

import java.beans.ConstructorProperties;

public class User {
    int id;
    String name;

    // required default constructor
    public User() {
        super();
    }

    @ConstructorProperties({ "id", "name" })
    public User(int id, String name) {
        super();
        this.id = id;
        this.name = name;
    }

    // getter, setter, hashCode, equals, toString
}

UserDao.java

import java.util.List;

import org.jdbi.v3.sqlobject.config.RegisterBeanMapper;
import org.jdbi.v3.sqlobject.statement.SqlQuery;
import org.jdbi.v3.sqlobject.statement.SqlUpdate;

public interface UserDao {
    @SqlUpdate("CREATE TABLE user (id INTEGER PRIMARY KEY, name VARCHAR)")
    void createTable();

    @SqlUpdate("INSERT INTO user(id, name) VALUES (?, ?)")
    void insertPositional(int id, String name);

    @SqlQuery("SELECT * FROM user ORDER BY name")
    @RegisterBeanMapper(User.class)
    List<User> listUsers();
}

ConstructorPropertiesExplore.java

import java.util.List;
import static org.assertj.core.api.Assertions.*;
import org.jdbi.v3.core.Jdbi;
import org.jdbi.v3.sqlobject.SqlObjectPlugin;

public class ConstructorPropertiesExplore {

    public static void main(String[] args) {
        Jdbi jdbi = Jdbi.create("jdbc:h2:mem:test");
        jdbi.installPlugin(new SqlObjectPlugin());

        List<User> users = jdbi.withExtension(UserDao.class, dao -> {
            dao.createTable();
            dao.insertPositional(0, "Alice");
            dao.insertPositional(1, "Bob");
            dao.insertPositional(2, "Clarice");
            dao.insertPositional(3, "David");

            return dao.listUsers();
        });

        assertThat(users).containsExactly(new User(0, "Alice"), new User(1, "Bob"), new User(2, "Clarice"),
                new User(3, "David"));
    }

}

具有@SqlQuery和@RegisterBeanMapper的Bean映射器无法实例化JDBI V3

2 个答案: