Flink 1.12.1 NoClassDefFoundError SourceFunction

Posted 2021-06-05 风真天

Flink 1.12.1 java.lang.NoClassDefFoundError: org/apache/flink/streaming/api/functions/source/SourceFunction

错误信息描述

使用Idea运行项目，抛出以下异常

java.lang.NoClassDefFoundError: org/apache/flink/streaming/api/functions/source/SourceFunction
	at java.lang.Class.getDeclaredMethods0(Native Method)
	at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
	at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
	at java.lang.Class.getMethod0(Class.java:3018)
	at java.lang.Class.getMethod(Class.java:1784)
	at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
	at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: org.apache.flink.streaming.api.functions.source.SourceFunction
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:355)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
	... 7 more
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" 

解决方案一

修改pom文件，把里面与flink有关的scope为provided的代码行注释，类似以下效果

<!-- This dependency is provided, because it should not be packaged into the JAR file. -->
<dependency>
	<groupId>org.apache.flink</groupId>
	<artifactId>flink-streaming-java_${scala.binary.version}</artifactId>
	<version>${flink.version}</version>
	<!-- <scope>provided</scope> -->
</dependency>
<dependency>
	<groupId>org.apache.flink</groupId>
	<artifactId>flink-clients_${scala.binary.version}</artifactId>
	<version>${flink.version}</version>
	<!-- <scope>provided</scope> -->
</dependency>

刷新Maven依赖，重新运行项目

maven reimport

解决方案二

我使用的是Idea 2020.3，通过调整idea配置，支持在项目运行时，将Provided的依赖有效

进入Edit Configurations

选择Modify options，选择Use classpath of module

选择Inclue dependencies with "Provided" scope