我正在使用配置为使用 flink-table jar（意思是我的程序的jar不包括 flink-table ). 使用以下代码

import org.apache.flink.api.common.typeinfo.TypeHint;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.operators.DataSource;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.api.java.typeutils.ResultTypeQueryable;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.TableEnvironment;
import org.apache.flink.table.api.java.BatchTableEnvironment;
import org.apache.flink.table.functions.AggregateFunction;
import org.apache.flink.types.Row;

import java.util.ArrayList;
import java.util.List;

public class JMain {
    public static void main(String[] args) throws Exception {
        ExecutionEnvironment execEnv = ExecutionEnvironment.getExecutionEnvironment();
        BatchTableEnvironment tableEnv = TableEnvironment.getTableEnvironment(execEnv);

        tableEnv.registerFunction("enlist", new Enlister());

        DataSource<Tuple2<String, String>> source = execEnv.fromElements(
                new Tuple2<>("a", "1"),
                new Tuple2<>("a", "2"),
                new Tuple2<>("b", "3")
        );

        Table table = tableEnv.fromDataSet(source, "a, b")
                .groupBy("a")
                .select("enlist(a, b)");

        tableEnv.toDataSet(table, Row.class)
                .print();
    }

    public static class Enlister
            extends AggregateFunction<List<String>, ArrayList<String>>
            implements ResultTypeQueryable<List<String>>
    {
        @Override
        public ArrayList<String> createAccumulator() {
            return new ArrayList<>();
        }

        @Override
        public List<String> getValue(ArrayList<String> acc) {
            return acc;
        }

        @SuppressWarnings("unused")
        public void accumulate(ArrayList<String> acc, String a, String b) {
            acc.add(a + ":" + b);
        }

        @SuppressWarnings("unused")
        public void merge(ArrayList<String> acc, Iterable<ArrayList<String>> it) {
            for (ArrayList<String> otherAcc : it) {
                acc.addAll(otherAcc);
            }
        }

        @SuppressWarnings("unused")
        public void resetAccumulator(ArrayList<String> acc) {
            acc.clear();
        }

        @Override
        public TypeInformation<List<String>> getProducedType() {
            return TypeInformation.of(new TypeHint<List<String>>(){});
        }
    }
}

我有个奇怪的例外：

org.apache.flink.table.api.ValidationException: Expression Enlister(List('a, 'b)) failed on input check: Given parameters do not match any signature. 
Actual: (java.lang.String, java.lang.String) 
Expected: (java.lang.String, java.lang.String)

但是，如果我不执行 ResultTypeQueryable ，我得到了预期的输出：

Starting execution of program
[b:3]
[a:1, a:2]
Program execution finished
Job with JobID 20497bd3efe44fab0092a05a8eb7d9de has finished.
Job Runtime: 270 ms
Accumulator Results: 
- 56e0e5a9466b84ae44431c9c4b7aad71 (java.util.ArrayList) [2 elements]

我的实际用例似乎需要 ResultTypeQueryable ，否则我会得到这个例外：

The return type of function ... could not be determined automatically,
due to type erasure. You can give type information hints by using the
returns(...) method on the result of the transformation call,
or by letting your function implement the 'ResultTypeQueryable' interface

有什么办法可以解决吗？