如何为Google数据流添加依赖项？

Question

I am trying to add opencv to a data-flow project. And from what I have read, all you should have to do is add the opencv jar and it will be uploaded to the staging bucket. But I know that cant be all (mostly doesn't work). I get the following error when I try to run my code as a direct pipeline on my local machine.

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Exception in thread "main" java.lang.UnsatisfiedLinkError: org.opencv.videoio.VideoCapture.VideoCapture_1(Ljava/lang/String;)J at org.opencv.videoio.VideoCapture.VideoCapture_1(Native Method) at org.opencv.videoio.VideoCapture.<init>(VideoCapture.java:40)

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I have read this post, How do I add Java dependencies to a Google Dataflow project? , but all it says it to add the jar to the classpath. Which doesnt work. I am missing something obvious I feel.

Answer 1

UnsatisfiedLinkError is: Thrown if the Java Virtual Machine cannot find an appropriate native-language definition of a method declared native. https://docs.oracle.com/javase/7/docs/api/java/lang/UnsatisfiedLinkError.html

Since the issue is occurring when you build/run locally, it is not related to the Dataflow Service or uploading to a staging bucket.

A quick Google search for "opencv UnsatisfiedLinkError" brought up many results. The most common response was that this line is missing:

static {
  System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
}