找不到请求的操作的编解码器：[timestamp <-> java.util.UUID]

Question

我在Cassandra中有一张桌子，试图对其进行迭代并从中提取东西。 我正在使用datastax Java驱动程序3.1.0。

CREATE TABLE test (
  client_id int,
  process_id text,
  last_modified_date timestamp,
  PRIMARY KEY ((client_id), process_id)
)

下面是代码：

private List<MetaHolder> getMetaHolder() {
    List<MetaHolder> metaHolder = new ArrayList<>();
    String sql = "select * from test where client_id=1";
    try {
      BoundStatement bs = Cache.getInstance().getStatement(sql);
      bs.setConsistencyLevel(ConsistencyLevel.QUORUM);

      ResultSet res = session.execute(bs);
      Iterator<Row> rows = res.iterator();
      while (rows.hasNext()) {
        Row row = rows.next();
        String processId = row.getString("PROCESS_ID");
        // this line throws exception
        UUID lastModifiedDate = row.getUUID("LAST_MODIFIED_DATE");
        MetaHolder metadata =
            new MetaHolder(processId, lastModifiedDate);
        metaHolder.add(metadata);
      }
    } catch (Exception ex) {
      LOGGER.logError("error= ", ExceptionUtils.getStackTrace(ex));
    }
    return metaHolder;
}

以下是例外：

error= com.datastax.driver.core.exceptions.CodecNotFoundException: Codec not found for requested operation: [timestamp <-> java.util.UUID]

有什么办法可以通过创建编解码器来使用JodaTime，而不是在代码中使用UUID？

Answer 1

更改以下代码

UUID lastModifiedDate = row.getUUID("LAST_MODIFIED_DATE");

至

Date lastModifiedDate = row.getTimestamp("LAST_MODIFIED_DATE");

您可以从日期获取joda DateTime

DateTime lastModifiedDateTime = new DateTime(lastModifiedDate);