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Posted to dev@flink.apache.org by "bai sui (Jira)" <ji...@apache.org> on 2021/10/15 04:27:00 UTC
[jira] [Created] (FLINK-24558) dataStream can not use multiple
classloaders
bai sui created FLINK-24558:
-------------------------------
Summary: dataStream can not use multiple classloaders
Key: FLINK-24558
URL: https://issues.apache.org/jira/browse/FLINK-24558
Project: Flink
Issue Type: Improvement
Components: API / DataStream
Reporter: bai sui
create a dataStream demo as below,in the demo,create a very simple example,
read stream data from sourceFunction,and send it to sinkFunction without any processing.
The point is,by creating the instance of SourceFunction and SinkFunction has used two separately URLClassLoader with different dependencies,for avoiding the code conflict .
but the problem is flink client send to server ,the server side throw an classNotFoundException which defined the de classloader dependencies, Obviously the server side has not use the classloader as client side.
how can I solve the problem ,is there any one can give me some advice ? thanks a lot
{code:java}
public class FlinkStreamDemo {
public static void main(String[] args) throws Exception {
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
SourceFunction<DTO> sourceFunc = createSourceFunction();
DataStreamSource<DTO> dtoDataStreamSource = env.addSource(sourceFunc);
SinkFunction<DTO> sinkFunction = createSink();
dtoDataStreamSource.addSink(sinkFunction);
env.execute("flink-example");
}
private static SinkFunction<DTO> createSink() {
URL[] urls = new URL[]{};
ClassLoader classLoader = new URLClassLoader(urls);
ServiceLoader<ISinkFunctionFactory> loaders = ServiceLoader.load(ISinkFunctionFactory.class, classLoader);
Iterator<ISinkFunctionFactory> it = loaders.iterator();
if (it.hasNext()) {
return it.next().create();
}
throw new IllegalStateException();
}
private static SourceFunction<DTO> createSourceFunction() {
URL[] urls = new URL[]{};
ClassLoader classLoader = new URLClassLoader(urls);
ServiceLoader<ISourceFunctionFactory> loaders = ServiceLoader.load(ISourceFunctionFactory.class, classLoader);
Iterator<ISourceFunctionFactory> it = loaders.iterator();
if (it.hasNext()) {
return it.next().create();
}
throw new IllegalStateException();
}
public interface ISinkFunctionFactory {
SinkFunction<DTO> create();
}
public interface ISourceFunctionFactory {
SourceFunction<DTO> create();
}
}
{code}
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