编译 Confluent KsqlDB 时的类型转换问题答案

【问题标题】：Type casting problem when compiling Confluent KsqlDB编译 Confluent KsqlDB 时的类型转换问题
【发布时间】：2020-01-03 15:58:58
【问题描述】：

我正在尝试编译（mvn pacakge with java 11.0.2）KSQL v5.3.1。

我在编译ksql-common时遇到以下错误：

[INFO] --- maven-surefire-plugin:2.21.0:test (default-test) @ ksql-common ---
[INFO] 
[INFO] -------------------------------------------------------
[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running io.confluent.ksql.util.WelcomeMsgUtilsTest
...
[INFO] Tests run: 11, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.014 s - in io.confluent.ksql.util.timestamp.StringToTimestampParserTest
[INFO] Running io.confluent.ksql.util.timestamp.TimestampExtractionPolicyFactoryTest
[ERROR] Tests run: 10, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.027 s <<< FAILURE! - in io.confluent.ksql.util.timestamp.TimestampExtractionPolicyFactoryTest
[ERROR] shouldThrowIfTimestampExtractorConfigIsInvalidClass(io.confluent.ksql.util.timestamp.TimestampExtractionPolicyFactoryTest)  Time elapsed: 0.009 s  <<< FAILURE!
java.lang.AssertionError: 

Expected: (an instance of io.confluent.ksql.util.KsqlException and exception with message a string containing "cannot be cast to org.apache.kafka.streams.processor.TimestampExtractor")
     but: exception with message a string containing "cannot be cast to org.apache.kafka.streams.processor.TimestampExtractor" message was "Cannot override default timestamp extractor: class io.confluent.ksql.util.timestamp.TimestampExtractionPolicyFactoryTest cannot be cast to class org.apache.kafka.streams.processor.TimestampExtractor (io.confluent.ksql.util.timestamp.TimestampExtractionPolicyFactoryTest and org.apache.kafka.streams.processor.TimestampExtractor are in unnamed module of loader 'app')"
Stacktrace was: io.confluent.ksql.util.KsqlException: Cannot override default timestamp extractor: class io.confluent.ksql.util.timestamp.TimestampExtractionPolicyFactoryTest cannot be cast to class org.apache.kafka.streams.processor.TimestampExtractor (io.confluent.ksql.util.timestamp.TimestampExtractionPolicyFactoryTest and org.apache.kafka.streams.processor.TimestampExtractor are in unnamed module of loader 'app')

帮助非常感谢；谢谢！

【问题讨论】：

我可以编译 v5.3.0...
正如@cricket_007 所说，您最好直接下载 Confluent Platform 下载。如果您真的想自己构建，请查看cnfl.io/slack 上的 ksqldb-dev 频道或 ksqldb-dev Google 群组groups.google.com/forum/#!forum/ksql-dev

标签： java junit apache-kafka confluent-platform ksqldb

【解决方案1】：

您可能想在 Github 上报告该问题，但我想包装说明包括跳过测试。

mvn package -DskipTests

否则，请随意下载 Confluent Platform 5.3.1 并且只配置和使用 ksql 属性，或者使用预构建的 Docker 镜像

【讨论】：