Hello, I'm trying to run the fraud detection example in https://nightlies.apache.org/flink/flink-docs-release-1.17/docs/try-flink/datastream, but I'm getting

NoClassDefFoundError

Here's what I did: 1. Run the Maven project

archetype:generate

command. 2.

cd frauddetection

3. Run

mvn clean package

4. Run

java -jar target/frauddetection-0.1.jar

What I get:

Error: Unable to initialize main class spendreport.FraudDetectionJob
Caused by: java.lang.NoClassDefFoundError: org/apache/flink/streaming/api/functions/source/SourceFunction

Note that I did not touch any of the project files. I created a Slack account to post this after scouring the internet for two hours and no solution. Any help would be appreciated.

A couple of things to check: 1. The playgrounds haven't been updated for 1.17, so maybe try with Flink 1.16 if you haven't already. 2. If I recall correctly, that particular playground isn't mean to work out-of-the-box. I think you have to supply some missing code (which is included in the docs).

NoClassDefFoundError

I think the problem is related to flink dependency scopes being set to "provided",

<!-- Apache Flink dependencies -->
		<!-- These dependencies are provided, because they should not be packaged into the JAR file. -->

Why shouldn't they be package into the JAR? I could not find an explanation anywhere. I assume that they would be necessary for the program to run. Am I building it wrong? I'm just doing

mvn package

;

java -jar myjar

. I could get the program to run when I set the dependency scopes to "compile" but I had to remove the exclusions for log4j dependencies in the shade config. How am I supposed to build a flink program? I can't fathom that the way to build one is change the maven config in an undocumented way for even the "quickstart" skeleton.

If you are trying to run the application in an IDE (e.g., IntelliJ), you'll need to modify the run configuration to include dependencies with the provided scope.