使用r2dbc驱动程序的Jooq反应式抓取

Question

    override fun getCredentialsById(id: Long): Mono<UserCredentialsModel> {
    return Mono.from {
        dsl.select(
                USER_CREDENTIALS.ID,
                USER_CREDENTIALS.EMAIL,
                USER_CREDENTIALS.PHONE,
                USER_CREDENTIALS.LOGIN,
                USER_CREDENTIALS.PASSWORD)
            .from(USER_CREDENTIALS)
            .where(USER_CREDENTIALS.ID.eq(id))
            .and(USER_CREDENTIALS.IS_ACTIVE.eq(true))
            .fetchInto(UserCredentialsModel::class.java)
    }
}

@Bean
fun createContext(): DSLContext {
    return DSL.using(connection)
}

org.jooq.exception.DetachedException: Attempt to execute a blocking method (e.g. Query.execute() or ResultQuery.fetch()) when only an R2BDC ConnectionFactory was configured

然后，我应该如何以反应式的方式将查询结果提取到Kotlin数据类（或Java Jooq的POJO）中？

Answer 1

当反应性地使用jOOQ时，您永远不应该调用任何阻塞方法，例如ResultQuery.FetchoneInto(Class)。该方法只是resultquery.fetchone()和record.into(Class)的方便方法。没有什么可以阻止您自己调用record.into(Class)，无论是在阻塞世界还是在非阻塞世界。

因此，使用通常的反应器库方法来映射流内容：

mono.map { r -> r.into(UserCredentialsModel::class.java) }

或者，在一个完整的示例中：

return Mono.from {
    dsl.select(
            USER_CREDENTIALS.ID,
            USER_CREDENTIALS.EMAIL,
            USER_CREDENTIALS.PHONE,
            USER_CREDENTIALS.LOGIN,
            USER_CREDENTIALS.PASSWORD)
        .from(USER_CREDENTIALS)
        .where(USER_CREDENTIALS.ID.eq(id))
        .and(USER_CREDENTIALS.IS_ACTIVE.eq(true))
} .map { r -> r.into(UserCredentialsModel::class.java) }