在 Flink-CEP 中检测模式的代码如下所示
// Generate temperature warnings for each matched warning pattern
DataStream<TemperatureEvent> warnings = tempPatternStream.select(
(Map<String, MonitoringEvent> pattern) -> {
TemperatureEvent first = (TemperatureEvent) pattern.get("first");
return new TemperatureEvent(first.getRackID(), first.getTemperature()) ;
}
);
如果在 Mac 中使用 command + F9 构建,则会显示以下错误
Exception in thread "main" org.apache.flink.api.common.functions.InvalidTypesException: The generic type parameters of 'Map' are missing.
It seems that your compiler has not stored them into the .class file.
Currently, only the Eclipse JDT compiler preserves the type information necessary to use the lambdas feature type-safely.
See the documentation for more information about how to compile jobs containing lambda expressions.
at org.apache.flink.api.java.typeutils.TypeExtractor.validateLambdaGenericParameter(TypeExtractor.java:1316)
at org.apache.flink.api.java.typeutils.TypeExtractor.validateLambdaGenericParameters(TypeExtractor.java:1302)
at org.apache.flink.api.java.typeutils.TypeExtractor.getUnaryOperatorReturnType(TypeExtractor.java:346)
at org.apache.flink.cep.PatternStream.select(PatternStream.java:64)
at org.stsffap.cep.monitoring.CEPMonitoring.main(CEPMonitoring.java:85
但是构建 usignmvn clean install
然后通过 Control + R 运行会显示输出,
我想知道为什么这一直在发生?
有什么办法可以做到吗?
PS:但是我正在使用 eclipse JDT 插件,即使那样它在日志中也显示错误。POM.XML 的内容是
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<compilerId>jdt</compilerId>
</configuration>
<dependencies>
<dependency>
<groupId>org.eclipse.tycho</groupId>
<artifactId>tycho-compiler-jdt</artifactId>
<version>0.21.0</version>
</dependency>
</dependencies>
</plugin>
非常欢迎提出建议。在此先感谢