Any advice would be appreciated :)
Thanks,
Dongwon
---------- Forwarded message ---------
From: Dongwon Kim <eastcirc...@gmail.com>
Date: Mon, Dec 14, 2020 at 11:27 PM
Subject: How to gracefully avoid "Generic types have been disabled in the
ExecutionConfig and type java.util.List is treated as a generic type"?
To: user <user@flink.apache.org>
Hi,
The following program compiles and runs w/o exceptions:
> public class Test {
>
> public static class A {
> private int n;
>
> public A() { }
> public int getN() { return n; }
> public void setN(int n) { this.n = n; }
> }
>
> public static class B {
> private List<A> lst;
>
> public B() { }
> public List<A> getLst() { return lst; }
> public void setLst(List<A> lst) { this.lst = lst; }
> }
>
> public static void main(String[] args) throws Exception {
> StreamExecutionEnvironment env =
> StreamExecutionEnvironment.createLocalEnvironment();
>
> env.fromElements(new B())
> .print();
>
> env.execute();
> }
> }
>
When I add the following line,
> env.getConfig().disableGenericTypes();
then the program shows me an exception:
> Exception in thread "main" java.lang.UnsupportedOperationException:
> Generic types have been disabled in the ExecutionConfig and type
> java.util.List is treated as a generic type.
> at
> org.apache.flink.api.java.typeutils.GenericTypeInfo.createSerializer(GenericTypeInfo.java:86)
> at
> org.apache.flink.api.java.typeutils.PojoTypeInfo.createPojoSerializer(PojoTypeInfo.java:319)
> at
> org.apache.flink.api.java.typeutils.PojoTypeInfo.createSerializer(PojoTypeInfo.java:311)
> at
> org.apache.flink.streaming.api.environment.StreamExecutionEnvironment.fromCollection(StreamExecutionEnvironment.java:970)
> at
> org.apache.flink.streaming.api.environment.StreamExecutionEnvironment.fromElements(StreamExecutionEnvironment.java:871)
> at Test.main(Test.java:29)
To avoid this exception, I found that I have to declare a type factory like:
> public static class BTypeFactory extends TypeInfoFactory<B> {
> @Override
> public TypeInformation<B> createTypeInfo(Type t, Map<String,
> TypeInformation<?>> genericParameters) {
> return Types.POJO(
> B.class,
> ImmutableMap.<String, TypeInformation<?>>builder()
> .put("lst", Types.LIST(Types.POJO(A.class)))
> .build()
> );
> }
> }
and give it to class B as follows:
> @TypeInfo(BTypeFactory.class)
> public static class B {
Is there no other way but to declare BTypeFactory in such cases?
I don't like the way I have to type a field name twice, one for a member
variable and the other for an Map entry in TypeInfoFactory.
Thanks in advance,
Dongwon
