JOOQ - 内联转换器未被应用

Question

在我的build.gradle文件中，我在forcedTypes中使用了一个转换器，在需要它的地方它可以正常工作。

forcedType {
    userType = 'java.util.List<stormsensor.thor.dto.telemetry.FlowEventType>'
    converter = 'stormsensor.thor.config.jooq.StringToFlowEventTypeListConverter'
    includeExpression = '.*\\.FLOW_EVENTS'
    includeTypes = '.*'
}

然而，我正在尝试将逗号分隔的字符串转换为特定用例的枚举列表：

DataType<List<FlowEventType>> LIST_TYPE = SQLDataType.VARCHAR.asConvertedDataType(new StringToFlowEventTypeListConverter());

ctx.select(
  groupConcatDistinct(NOTIFICATION_RULE.FLOW_EVENT_TYPE).as(field(name("notifications"), LIST_TYPE))
)
.from(NOTIFICATION_RULE)
.groupBy(MONITORING_POINT_ID)
.fetchInto(BatchNotificationRuleModel.class);

这会抛出一个异常

org.jooq.exception.MappingException: An error ocurred when mapping record to class stormsensor.thor.dto.notification.batch.BatchNotificationRuleModel
    at org.jooq.impl.DefaultRecordMapper$MutablePOJOMapper.map(DefaultRecordMapper.java:802)
    at org.jooq.impl.DefaultRecordMapper.map(DefaultRecordMapper.java:500)
    at org.jooq.impl.ResultImpl.into(ResultImpl.java:1284)
    at org.jooq.impl.AbstractResultQuery.fetchInto(AbstractResultQuery.java:1550)
    at org.jooq.impl.SelectImpl.fetchInto(SelectImpl.java:3746)
    at stormsensor.thor.repository.notification.BatchNotificationRuleRepositoryJdbcImpl.save(BatchNotificationRuleRepositoryJdbcImpl.java:98)
Caused by: org.jooq.exception.DataTypeException: Cannot convert from CRITICAL_DEPTH,NON_TIDAL_CSO (class java.lang.String) to interface java.util.List
    at org.jooq.tools.Convert$ConvertAll.fail(Convert.java:1194)
    at org.jooq.tools.Convert$ConvertAll.from(Convert.java:1083)
    at org.jooq.tools.Convert.convert0(Convert.java:324)
    at org.jooq.tools.Convert.convert(Convert.java:316)
    at org.jooq.tools.Convert.convert(Convert.java:387)
    at org.jooq.impl.AbstractRecord.get(AbstractRecord.java:275)
    at org.jooq.impl.DefaultRecordMapper$MutablePOJOMapper.map(DefaultRecordMapper.java:830)
    at org.jooq.impl.DefaultRecordMapper$MutablePOJOMapper.map(DefaultRecordMapper.java:762)
    ... 72 more

这是我正在获取的模型：

@Data
@NoArgsConstructor
public class BatchNotificationRuleModel implements Serializable {
    private static final long serialVersionUID = 1L;

    private List<FlowEventType> notifications;
    private List<MessageProtocolType> protocols;
}

我有所遗漏吗？

更新：

我能够使用内联方式进行转换

//...
.groupBy(MONITORING_POINT_ID)
.fetchStream().map(e -> {
    Converter<String, List<FlowEventType>> converter = new StringToFlowEventTypeListConverter();
    List<FlowEventType> notifications = e.get(field(name("notifications"), String.class), converter);
    return BatchNotificationRuleModel.builder().notifications(notifications).build();
}).collect(toList());

我应用的初始转换器和后期地图转换之间有什么区别？

- John Alexander

Answer 1

虽然我们可能认为Field.as(Field)应该使用参数字段的名称和类型进行类型转换，但事实并非如此。根据Javadoc的说明：

基于另一个字段的名称创建此字段的别名。

为了将表达式强制转换为所需的数据类型，你需要手动执行以下操作：

groupConcatDistinct(NOTIFICATION_RULE.FLOW_EVENT_TYPE)
  .coerce(LIST_TYPE)
  .as("notifications")

请看：

查看Field.coerce(DataType)

- Lukas Eder